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Stir Bar Sorptive Extraction (SBSE), a novel extraction technique for aqueous samples: theory and principles
Baltussen, H.A.; Sandra, P.J.F.; David, F.; Cramers, C.A.M.G.
The theory and practice of a novel approach for sample enrichment, namely the application of stir bars coated with the sorbent polydimethylsiloxane (PDMS) and referred to as stir bar sorptive extraction (SBSE) are presented. Stir bars with a length of 10 and 40 mm coated with 55 and 219 L of PDMS
Atmospheric pressure gas chromatography–time-of-flight-mass spectrometry (APGC–ToF-MS) for the determination of regulated and emerging contaminants in aqueous samples after stir bar sorptive extraction (SBSE)
International Nuclear Information System (INIS)
Pintado-Herrera, Marina G.; González-Mazo, Eduardo; Lara-Martín, Pablo A.
Graphical abstract: Examples of identification of target (triclosan, TCS) and non-target (tributhyl phosphate, TBP) compounds in environmental water samples by APGC–ToF-MS. Some confirmation criteria are shown (i.e. mass spectra, isotopic distribution, and accurate mass). - Highlights: • 102 regulated and emerging contaminants are simultaneously extracted by SBSE. • APGC–ToF-MS is presented as an alternative to EI for the analysis of microcontaminants. • Identification of non-target compounds in environmental matrices is also explored. - Abstract: This work presents the development, optimization and validation of a multi-residue method for the simultaneous determination of 102 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and several types of pesticides in aqueous matrices. Water samples were processed using stir bar sorptive extraction (SBSE) after the optimization of several parameters: agitation time, ionic strength, presence of organic modifiers, pH, and volume of the derivatizing agent. Target compounds were extracted from the bars by liquid desorption (LD). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to time-of-flight (ToF-MS) mass spectrometry. A new ionization source, atmospheric pressure gas chromatography (APGC), was tested. The optimized protocol showed acceptable recovery percentages (50–100%) and limits of detection below 1 ng L −1 for most of the compounds. Occurrence of 21 out of 102 analytes was confirmed in several environmental aquatic matrices, including seawater, sewage effluent, river water and groundwater. Non-target compounds such as organophosphorus flame retardants were also identified in real samples by accurate mass measurement of their molecular ions using GC-APGC–ToF-MS. To the best of our knowledge, this is the first time that this
Atmospheric pressure gas chromatography–time-of-flight-mass spectrometry (APGC–ToF-MS) for the determination of regulated and emerging contaminants in aqueous samples after stir bar sorptive extraction (SBSE)
Energy Technology Data Exchange (ETDEWEB)
Pintado-Herrera, Marina G.; González-Mazo, Eduardo; Lara-Martín, Pablo A., E-mail: firstname.lastname@example.com
Graphical abstract: Examples of identification of target (triclosan, TCS) and non-target (tributhyl phosphate, TBP) compounds in environmental water samples by APGC–ToF-MS. Some confirmation criteria are shown (i.e. mass spectra, isotopic distribution, and accurate mass). - Highlights: • 102 regulated and emerging contaminants are simultaneously extracted by SBSE. • APGC–ToF-MS is presented as an alternative to EI for the analysis of microcontaminants. • Identification of non-target compounds in environmental matrices is also explored. - Abstract: This work presents the development, optimization and validation of a multi-residue method for the simultaneous determination of 102 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and several types of pesticides in aqueous matrices. Water samples were processed using stir bar sorptive extraction (SBSE) after the optimization of several parameters: agitation time, ionic strength, presence of organic modifiers, pH, and volume of the derivatizing agent. Target compounds were extracted from the bars by liquid desorption (LD). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to time-of-flight (ToF-MS) mass spectrometry. A new ionization source, atmospheric pressure gas chromatography (APGC), was tested. The optimized protocol showed acceptable recovery percentages (50–100%) and limits of detection below 1 ng L{sup −1} for most of the compounds. Occurrence of 21 out of 102 analytes was confirmed in several environmental aquatic matrices, including seawater, sewage effluent, river water and groundwater. Non-target compounds such as organophosphorus flame retardants were also identified in real samples by accurate mass measurement of their molecular ions using GC-APGC–ToF-MS. To the best of our knowledge, this is the first time that this
Atmospheric pressure gas chromatography-time-of-flight-mass spectrometry (APGC-ToF-MS) for the determination of regulated and emerging contaminants in aqueous samples after stir bar sorptive extraction (SBSE).
Pintado-Herrera, Marina G; González-Mazo, Eduardo; Lara-Martín, Pablo A
This work presents the development, optimization and validation of a multi-residue method for the simultaneous determination of 102 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and several types of pesticides in aqueous matrices. Water samples were processed using stir bar sorptive extraction (SBSE) after the optimization of several parameters: agitation time, ionic strength, presence of organic modifiers, pH, and volume of the derivatizing agent. Target compounds were extracted from the bars by liquid desorption (LD). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to time-of-flight (ToF-MS) mass spectrometry. A new ionization source, atmospheric pressure gas chromatography (APGC), was tested. The optimized protocol showed acceptable recovery percentages (50-100%) and limits of detection below 1ngL(-1) for most of the compounds. Occurrence of 21 out of 102 analytes was confirmed in several environmental aquatic matrices, including seawater, sewage effluent, river water and groundwater. Non-target compounds such as organophosphorus flame retardants were also identified in real samples by accurate mass measurement of their molecular ions using GC-APGC-ToF-MS. To the best of our knowledge, this is the first time that this technique has been applied for the analysis of contaminants in aquatic systems. By employing lower energy than the more widely used electron impact ionization (EI), AGPC provides significant advantages over EI for those substances very susceptible to high fragmentation (e.g., fragrances, pyrethroids). Copyright © 2014 Elsevier B.V. All rights reserved.
The use of stir bar sorptive extraction-A potential alternative method for the determination of furan, evaluated using two example food matrices
Energy Technology Data Exchange (ETDEWEB)
Ridgway, Kathy, E-mail: firstname.lastname@example.com [Safety and Environmental Assurance Centre, Unilever Colworth, Bedfordshire, MK44 1LQ (United Kingdom); Lalljie, Sam P.D. [Safety and Environmental Assurance Centre, Unilever Colworth, Bedfordshire, MK44 1LQ (United Kingdom); Smith, Roger M. [Department of Chemistry, Loughborough University, Loughborough, Leics, LE11 3TU (United Kingdom)
A comparison is made between static headspace analysis and stir bar sorptive extraction (SBSE) for the quantitative determination of furan. The SBSE technique was optimised and evaluated using two example food matrices (coffee and jarred baby food). The use of the SBSE technique in most cases, gave comparable results to the static headspace method, using the method of standard additions with d{sub 4}-labelled furan as an internal standard. Using the SBSE method, limits of detection down to 2 ng g{sup -1} were achieved, with only a 1 h extraction. The method was performed at ambient temperatures, thus eliminating the possibility of formation of furan during extraction.
The use of stir bar sorptive extraction-A potential alternative method for the determination of furan, evaluated using two example food matrices
International Nuclear Information System (INIS)
Ridgway, Kathy; Lalljie, Sam P.D.; Smith, Roger M.
A comparison is made between static headspace analysis and stir bar sorptive extraction (SBSE) for the quantitative determination of furan. The SBSE technique was optimised and evaluated using two example food matrices (coffee and jarred baby food). The use of the SBSE technique in most cases, gave comparable results to the static headspace method, using the method of standard additions with d 4 -labelled furan as an internal standard. Using the SBSE method, limits of detection down to 2 ng g -1 were achieved, with only a 1 h extraction. The method was performed at ambient temperatures, thus eliminating the possibility of formation of furan during extraction.
Solid phase microextraction and stir bar sorptive extraction for organotin compounds - a comparison (P9)
International Nuclear Information System (INIS)
Mothes, S.; Wennrich, R.
Full text: Organotin compounds have been largely used in agricultural and industrial applications. Hyphenated techniques were developed for the sensitive and selective determination of such species. For this task GC has been coupled with atomic emission detection. Derivatization to transform the Sn-compounds into sufficiently volatile compounds was necessary and carried out using sodium tetrapropylborate. For sample preparation the application of solid phase microextraction (SPME) give recent advances in comparison to classical liquid-liquid extraction (LEE). A problem in the usage of SPME exists however in the small volume of the PDMS coating for enrichment the analytes. For improvement of both sample enrichment and extraction of the organotin compounds stir bar sorptive extraction (SBSE) was applied. It base on the application of stir bars coated with PDMS. Here the extraction yield is substantially higher. Aim of this study was to compare the capabilities of GC-AED in combination with SPME and SBSE. After optimization of the experimental parameters it was possible to reach detection limits in the pg / 1 - level. A comparison of both methods shows the expected results. By application of SBSE it was possible to increase the detection limits one order of magnitude. With SPME the reproducibility of the analytical results (in the 1 ng / 1 concentration range) was found to be between 10 and 15 %, it could be enhanced to 5-8 % by application of SBSE. These low limits of detection and the good reproducibility allowed the determination of organotin compounds according required regulations. Ref. 1 (author)
Development, optimisation and application of polyurethane foams as new polymeric phases for stir bar sorptive extraction.
Neng, N R; Pinto, M L; Pires, J; Marcos, P M; Nogueira, J M F
In this contribution, polyurethane foams are proposed as new polymeric phases for stir bar sorptive extraction (SBSE). Assays performed for polyurethane synthesis demonstrated that four series of formulations (P(1), P(2), P(3) and P(4)) present remarkable stability and excellent mechanical resistance to organic solvents. For polymer clean-up treatment, acetonitrile proved to be the best solvent under sonification, ensuring the reduction of the contamination and interferences. SBSE assays performed on these polyurethane polymers followed by liquid desorption and high-performance liquid chromatography-diode array detection (LD-HPLC-DAD) or large volume injection-capillary gas chromatography-mass spectrometry (LD-LVI-GC-MS), showed that P(2) presents the best recovery yields for atrazine, 2,3,4,5-tetrachlorophenol and fluorene, used as model compounds in water samples at a trace level. SBSE(P(2)) assays performed on this polymer mixed up with several adsorbent materials, i.e. activated carbon, a mesoporous material and a calixarene, did not bring any advantages in relation with the polymeric matrix alone. The comparison between assays performed by SBSE(P(2)) and by the conventional SBSE(PDMS) showed much better performance for the former phase on aqueous samples spiked with atrazine, 2,3,4,5-tetrachlorophenol and fluorene, in which the foremost two analytes present recovery values 3- and 10-fold higher, respectively. The polyurethanes proposed as new polymeric phases for SBSE provided powerful capabilities for the enrichment of organic compounds from aqueous matrices, showing to be indicated mainly in the case of the more polar analytes.
Pesticide residue determination in surface waters by stir bar sorptive extraction and liquid chromatography/tandem mass spectrometry.
Giordano, A; Fernández-Franzón, M; Ruiz, M J; Font, G; Picó, Y
In this stir bar sorptive extraction (SBSE) method, 16 pesticides were extracted from surface water samples by sorption onto 1 mm polydimethylsiloxane layer coated on a 10-mm-length stir bar magnet. After liquid desorption of the analytes with 1 ml of methanol, the detection was performed on a liquid chromatography-tandem mass spectrometry with a triple quadrupole (QqQ) analyzer using selected reaction monitoring mode via electrospray ionization. Parameters affecting SBSE operation, including sample volume, salt addition, extraction time, stirring rate, and desorption conditions, have been evaluated. The optimized SBSE method required two 50 ml aliquots of surface water samples, one aliquot was added of 30% NaCl and stirred at 900 rpm during 1 h for testing five pesticides with log K(o/w) 3. The method was validated in spiked surface water samples at limits of quantifications (LOQs) and ten times the LOQs showing recoveries Albufera Lake and surrounding channels, showing that SBSE is a powerful tool for routine control analysis of pesticide residues in surface water.
Chiral imprinted polymers as enantiospecific coatings of stir bar sorptive extraction devices.
Gomez-Caballero, Alberto; Guerreiro, Antonio; Karim, Kal; Piletsky, Sergey; Goicolea, M Aranzazu; Barrio, Ramon J
This paper reports the design of Molecularly Imprinted Polymers (MIP) with affinity towards (S)-citalopram using computational modeling for the selection of functional monomers and monomer:template ratio. Acrylamide was selected as functional monomer and the final complex functional monomer/template resulted in a 3:1 ratio. The polymer was synthesized by radical polymerization initiated by UV onto magnetic stir-bars in order to obtain a stir bar sorptive extraction (SBSE) device capable of selective enantiomeric recognition. After successful template removal, the parameters affecting the SBSE procedure (sample volume, ionic strength, extraction time and pH) were optimized for the effective rebinding of the target analyte. The resultant chirally imprinted polymer based stir-bar was able to selectively extract (S)-citalopram from a racemic mixture in an aqueous media with high specificity (specificity factor 4) between 25 and 500 μgL(-1). The MIP coated stir-bars can have significance for enantiospecific sample pre-concentration and subsequent analysis without the need for any chiral chromatographic separation. Copyright © 2011 Elsevier B.V. All rights reserved.
Stir bar sorptive extraction with EG-Silicone coating for bisphenols determination in personal care products by GC-MS.
Cacho, Juan Ignacio; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel
An easy to perform analytical method for the determination of three bisphenol compounds (BPs) in commonly used personal care products (PCPs) is presented. Ethylene glycol-silicone (EG-Silicone) coated stir bars, which have recently become commercially available, are evaluated in this study for the simultaneous determination of bisphenol A (BPA), bisphenol F (BPF) and bisphenol Z (BPZ) by stir bar sorptive extraction (SBSE) in combination with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). This new sorptive extraction phase allows the analysis of these compounds without any previous derivatization procedure. Different parameters affecting both SBSE extraction and thermal desorption were carefully optimized, using experimental designs based on the Taguchi orthogonal arrays. The procedure was applied to analyzing easily bought PCPs, providing detection limits of about 8 ng g(-1), with precisions lower than 11% in terms of relative standard deviation. Recovery studies performed at two different concentration levels provided satisfactory values for all the compounds. The analyzed personal care samples contained BPA at concentration levels ranging from 30.9 to 88.3 ng g(-1). Copyright © 2013 Elsevier B.V. All rights reserved.
Etched poly(ether ether ketone) jacket stir bar with detachable dumbbell-shaped structure for stir bar sorptive extraction.
Zhou, Wei; Wang, Chenlu; Wang, Xuemei; Chen, Zilin
Development of stir bar sorptive extraction (SBSE) device with high stability and extraction efficiency is critical and challenging by date. In this work, etched poly(ether ether ketone) (PEEK) tube with high mechanical strength and large specific surface area was used as jacket for SBSE device. By etching with concentrated sulfuric acid, the smooth outer surface of PEEK become porous with plenty of micro holes, which was beneficial for coating of sorbents and significantly improved the extraction performance. After functionalized by bio-polydopamine method, strong hydrophobic p-naphtholbenzein molecular was immobilized onto the chemical resistant PEEK surface (PNB@E-PEEK) as stationary phase. We also firstly developed a simple detachable dumbbell-shaped structure for improving the workability of PEEK jacket stir bar. The dumbbell-shaped construction can eliminate the friction between stir bar and container, and the design of detachable structure make elution can be accomplished easier with small amount of organic solvent. It was interesting that the developed detachable dumbbell-shaped PNB@E-PEEK stir bar showed exceptional stability and extraction efficiency for SBSE enrichment of multiple analytes including several Sudan dyes, triazines, polycyclic aromatic hydrocarbons (PAHs), alkaloids and flavonoid. By coupling with high performance liquid chromatography-ultraviolet detection (HPLC-UV), PNB@E-PEEK stir bar based SBSE-HPLC-UV method was applied for the analysis of common Sudan dye pollutants. The method showed low limits of detection (0.02-0.03 ng/mL), good linearity (R 2 ≥ 0.9979) and good reproducibility (relative standard deviation ≤ 7.96%). It has been successfully applied to determine three dye pollutants in tap and lake water. Copyright © 2018 Elsevier B.V. All rights reserved.
Comparison of a disposable sorptive sampler with thermal desorption in a gas chromatographic inlet, or in a dedicated thermal desorber, to conventional stir bar sorptive extraction-thermal desorption for the determination of micropollutants in water.
Wooding, Madelien; Rohwer, Egmont R; Naudé, Yvette
The presence of micropollutants in the aquatic environment is a worldwide environmental concern. The diversity of micropollutants and the low concentration levels at which they may occur in the aquatic environment have greatly complicated the analysis and detection of these chemicals. Two sorptive extraction samplers and two thermal desorption methods for the detection of micropollutants in water were compared. A low-cost, disposable, in-house made sorptive extraction sampler was compared to SBSE using a commercial Twister sorptive sampler. Both samplers consisted of polydimethylsiloxane (PDMS) as a sorptive medium to concentrate micropollutants. Direct thermal desorption of the disposable samplers in the inlet of a GC was compared to conventional thermal desorption using a commercial thermal desorber system (TDS). Comprehensive gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS) was used for compound separation and identification. Ten micropollutants, representing a range of heterogeneous compounds, were selected to evaluate the performance of the methods. The in-house constructed sampler, with its associated benefits of low-cost and disposability, gave results comparable to commercial SBSE. Direct thermal desorption of the disposable sampler in the inlet of a GC eliminated the need for expensive consumable cryogenics and total analysis time was greatly reduced as a lengthy desorption temperature programme was not required. Limits of detection for the methods ranged from 0.0010 ng L -1 to 0.19 ng L -1 . For most compounds, the mean (n = 3) recoveries ranged from 85% to 129% and the % relative standard deviation (% RSD) ranged from 1% to 58% with the majority of the analytes having a %RSD of less than 30%. Copyright © 2017 Elsevier B.V. All rights reserved.
Determination of short chain chlorinated paraffins in water by stir bar sorptive extraction-thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry.
Tölgyessy, P; Nagyová, S; Sládkovičová, M
A simple, robust, sensitive and environment friendly method for the determination of short chain chlorinated paraffins (SCCPs) in water using stir bar sorptive extraction (SBSE) coupled to thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry (TD-GC-QqQ-MS/MS) was developed. SBSE was performed using 100mL of water sample, 20mL of methanol as a modifier, and a commercial sorptive stir bar (with 10mm×0.5mm PDMS layer) during extraction period of 16h. After extraction, the sorptive stir bar was thermally desorbed and online analysed by GC-MS/MS. Method performance was evaluated for MilliQ and surface water spiked samples. For both types of matrices, a linear dynamic range of 0.5-3.0μgL -1 with correlation coefficients >0.999 and relative standard deviations (RSDs) of the relative response factors (RRFs) <12% was established. The limits of quantification (LOQs) of 0.06 and 0.08μgL -1 , and the precision (repeatability) of 6.4 and 7.7% (RSDs) were achieved for MilliQ and surface water, respectively. The method also showed good robustness, recovery and accuracy. The obtained performance characteristics indicate that the method is suitable for screening and monitoring and compliance checking with environmental quality standards (EQS, set by the EU) for SCCPs in surface waters. Copyright © 2017 Elsevier B.V. All rights reserved.
Determination of synthetic phenolic antioxidants in soft drinks by stir-bar sorptive extraction coupled to gas chromatography-mass spectrometry.
Cacho, Juan Ignacio; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel
The synthetic phenolic antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) were pre-concentrated by stir-bar sorptive extraction and thermally desorbed (SBSE-TD) before analysis by GC-MS. Several parameters affecting the derivatisation step and both SBSE extraction and thermal desorption were carefully optimised. When the analyses of BHA and TBHQ in their acetylated, silylated and underivatised forms were compared, the best results were obtained when the in-situ derivatisation procedure with acetic anhydride was employed. Quantification was carried out using carvacrol as the internal standard, providing quantification limits of between 0.11 and 0.15 ng ml(-1), depending on the compound. Recovery assays for samples spiked at two concentration levels, 1 and 5 ng ml(-1), provided recoveries in the 81-117% range. The proposed method was applied in the analysis canned soft drinks and the analytes were found in five of the 10 samples analysed.
Simple and sensitive monitoring of sulfonamide veterinary residues in milk by stir bar sorptive extraction based on monolithic material and high performance liquid chromatography analysis.
Huang, Xiaojia; Qiu, Ningning; Yuan, Dongxing
A simple, rapid, and sensitive method for the quantitative monitoring of five sulfonamide antibacterial residues (SAs) in milk was developed by stir bar sorptive extraction (SBSE) coupling to high performance liquid chromatography with diode array detection. The analytes were concentrated by SBSE based on poly (vinylimidazole-divinylbenzene) monolithic material as coating. The extraction procedure was very simple, milk was diluted with water then directly sorptive extraction without elimination of fats and protein in samples was required. To achieve optimum extraction performance for SAs, several parameters, including extraction and desorption time, desorption solvent, ionic strength and pH value of sample matrix were investigated. Under the optimized experimental conditions, low detection limits (S/N=3) quantification limits (S/N=10) of the proposed method for the target compounds were achieved within the range of 1.30-7.90 ng/mL and 4.29-26.3 ng/mL from spiked milk, respectively. Good linearities were obtained for SAs with the correlation coefficients (R(2)) above 0.996. Finally, the proposed method was successfully applied to the determination of SAs compounds in different milk samples and satisfied recoveries of spiked target compounds in real samples were obtained.
New Functionalized Sol-Gel Hybrid Sorbent Coating for Stir Bar Sorptive Extraction of Selected Non-Steroidal Anti Inflammatory Drugs in Human Urine Samples
International Nuclear Information System (INIS)
Mashkurah Abd Rahim; Wan Aini Wan Ibrahim; Zainab Ramli; Mohd Marsin Sanagi
A new sol-gel hybrid material, methyltrimethoxysilane-cyanopropyltriethoxysilane (MTMOS-CNPrTEOS) was successfully synthesized and used as a coating material in stir bar sorptive extraction (SBSE) of selected non-steroidal anti-inflammatory drugs (NSAIDs) in urine samples. The MTMOS-CNPrTEOS hybrid was synthesized by hydrolysis and condensation of MTMOS and CNPrTEOS in the presence of trifluoroacetic acid as catalyst via sol-gel method. Several factors influencing the synthesized sol-gel hybrid MTMOS-CNPrTEOS process such as mole ratio of MTMOS-CNPrTEOS, NaOH concentrations as etching solution, etching time, coating time and water content were investigated and optimized in this study. The optimum synthesis conditions obtained were 1:1 mol ratio of MTMOS-CNPrTEOS, 1 M NaOH as etching solution, 60 min etching time, 2 h coating time and 6 mmol water. The sol-gel hybrid MTMOS-CNPrTEOS synthesized under the optimum conditions was used to determine selected NSAIDs in human urine samples using normal stacking mode capillary electrophoresis with ultraviolet detection. MTMOS-CNPrTEOS SBSE method demonstrated good linearity (60 to 20,000 μg L -1 ) with excellent coefficient of determination (r 2 > 0.9990). The sol-gel hybrid MTMOS-CNPrTEOS SBSE method showed low limit of detection (35 - 41 μg L -1 ) with good precision (RSD < 6 %, n = 3) and excellent extraction recoveries (83.5 - 98.9 %) for the selected NSAIDs. The sol-gel hybrid MTMOS-CNPrTEOS SBSE method demonstrated good potential as an alternative sorbent in SBSE method for NSAIDs. (author)
Analysis of Volatile Components of Varietal English Wines Using Stir Bar Sorptive Extraction/Gas Chromatography-Mass Spectrometry
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Darren J. Caven-Quantrill
Full Text Available Aroma is an important property of wine and it can be influenced significantly by enological practices. The aim of this work was, by use of stir bar sorptive extraction/gas chromatography-mass spectrometry (SBSE/GC-MS, to compare semi-quantitative concentrations of the volatile constituents of stainless steel tank-fermented/matured Huxelrebe, Ortega, Schönburger and Siegerrebe varietal wines from a commercial English vineyard, with corresponding wines produced by oak cask ('barrel' fermentation/maturation. Aroma profiles of tank and barrel wines were different, with more volatiles detected and net concentrations being higher in barrel wines. Long chain ethyl carboxylate esters were generally more abundant in barrel wines, whereas acetate esters were generally more prominent in tank wines. By conducting a short (~7 month maturation period in secondhand (third or fourth fill casks, it was possible to make wines with more complex aromas, but without obvious oak aroma.
C18-coated stir bar sorptive extraction combined with high performance liquid chromatography-electrospray tandem mass spectrometry for the analysis of sulfonamides in milk and milk powder.
Yu, Chunhe; Hu, Bin
A simple, rapid, sensitive, inexpensive and less sample consuming method of C(18)-stir bar sorptive extraction (SBSE)-high performance liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) was proposed for the determination of six sulfonamides in milk and milk powder samples. C(18) silica particles coated stir bar was prepared by adhesion method, and two kinds of adhesive glue, polydimethylsiloxane (PDMS) sol and epoxy glue were tried. It was found that the C(18)-coated stir bar prepared by PDMS sol as adhesive glue is more robust than that prepared by epoxy glue when liquid desorption was employed, in terms of both lifetime and organic solvent tolerance. The preparation of C(18) stir bar was simple with good mechanic strength and the stir bar could be reused for more than 20 times. Granular coating has relatively high specific surface area and is propitious to sorptive extraction based process. Compared to conventional PDMS SBSE coating, C(18) coating shows good affinity to the target polar/weak polar sulfonamides. To achieve optimum SBSE extraction performance, several parameters including extraction and desorption time, ionic strength, sample pH and stirring speed were investigated. The detection limits of the proposed method for six sulfonamides were in the range of 0.9-10.5 μg/L for milk and 2.7-31.5 μg/kg for milk powder. Good linearities were obtained for sulfonamides with the correlation coefficients (R) above 0.9922. Finally, the proposed method was successfully applied to the determination of sulfonamides in milk and milk powder samples and satisfied recoveries of spiked target compounds in real samples were obtained. Copyright © 2012 Elsevier B.V. All rights reserved.
Determination of Carvedilol Enantiomers in Pharmaceutical Dosages by SBSE-HPLC Based on Diastereomer Formation.
Taraji, Maryam; Talebpour, Zahra; Adib, Nuoshin; Karimi, Shima; Haghighi, Farideh; Aboul-Enein, Hassan Y
A sensitive, selective and simple method for the simultaneous determination of carvedilol enantiomers in aqueous solution has been developed using stir bar sorptive extraction (SBSE) followed by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. This method is based on the reaction of carvedilol enantiomers with (-)-menthyl chloroformate (MCF) after extraction by the SBSE method to produce diastereomeric derivatives. The separation was achieved by use of a C18 analytical column and the influence of mobile phase composition on the enantioseparation of carvedilol was studied. The applicability of two sorptive phases, poly(methyl methacrylate/ethyleneglycol dimethacrylate) (PA-EG) and polydimethylsiloxane, were tested for extraction of carvedilol enantiomers from aqueous samples. The obtained results showed excellent linear dynamic ranges and precisions for each of them. The least limit of detection for (S)- and (R)-carvedilol obtained 8 and 11 µg L(-1), respectively, using the PA-EG sorptive phase. Inter- and intra-mean recoveries were also satisfactory, ranging from 98 to 103%, with coefficient of variation in the range of 1-5% at three fortified levels using a PA-EG coated stir bar. The proposed SBSE (PA-EG)-MCF derivatization-HPLC-UV method was successfully applied to enantioselective analysis of carvedilol in water and pharmaceutical dosages, confirming the application of this method. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: firstname.lastname@example.com.
Development of a microwave assisted extraction method for the analysis of 2,4,6-trichloroanisole in cork stoppers by SIDA-SBSE-GC-MS
International Nuclear Information System (INIS)
Vestner, Jochen; Fritsch, Stefanie; Rauhut, Doris
The aim of this research work was focused on the replacement of the time-consuming soaking of cork stoppers which is mainly used as screening method for cork lots in connection with sensory analysis and/or analytical methods to detect releasable 2,4,6-trichloroanisole (TCA) of natural cork stoppers. Releasable TCA from whole cork stoppers was analysed with the application of a microwave assisted extraction method (MAE) in combination with stir bar sorptive extraction (SBSE). The soaking of corks (SOAK) was used as a reference method to optimise MAE parameters. Cork lots of different quality and TCA contamination levels were used to adapt MAE. Pre-tests indicated that an MAE at 40 deg. C for 120 min with 90 min of cooling time are suitable conditions to avoid an over-extraction of TCA of low and medium tainted cork stoppers in comparison to SOAK. These MAE parameters allow the measuring of almost the same amounts of releasable TCA as with the application of the soaking procedure in the relevant range ( -1 releasable TCA from one cork) to evaluate the TCA level of cork stoppers. Stable isotope dilution assay (SIDA) was applied to optimise quantification of the released TCA with deuterium-labelled TCA (TCA-d 5 ) using a time-saving GC-MS technique in single ion monitoring (SIM) mode. The developed MAE method allows the measuring of releasable TCA from the whole cork stopper under improved conditions and in connection with a low use of solvent and a higher sample throughput.
Development of a microwave assisted extraction method for the analysis of 2,4,6-trichloroanisole in cork stoppers by SIDA-SBSE-GC-MS.
Vestner, Jochen; Fritsch, Stefanie; Rauhut, Doris
The aim of this research work was focused on the replacement of the time-consuming soaking of cork stoppers which is mainly used as screening method for cork lots in connection with sensory analysis and/or analytical methods to detect releasable 2,4,6-trichloroanisole (TCA) of natural cork stoppers. Releasable TCA from whole cork stoppers was analysed with the application of a microwave assisted extraction method (MAE) in combination with stir bar sorptive extraction (SBSE). The soaking of corks (SOAK) was used as a reference method to optimise MAE parameters. Cork lots of different quality and TCA contamination levels were used to adapt MAE. Pre-tests indicated that an MAE at 40 degrees C for 120 min with 90 min of cooling time are suitable conditions to avoid an over-extraction of TCA of low and medium tainted cork stoppers in comparison to SOAK. These MAE parameters allow the measuring of almost the same amounts of releasable TCA as with the application of the soaking procedure in the relevant range (cork) to evaluate the TCA level of cork stoppers. Stable isotope dilution assay (SIDA) was applied to optimise quantification of the released TCA with deuterium-labelled TCA (TCA-d(5)) using a time-saving GC-MS technique in single ion monitoring (SIM) mode. The developed MAE method allows the measuring of releasable TCA from the whole cork stopper under improved conditions and in connection with a low use of solvent and a higher sample throughput. Copyright 2009 Elsevier B.V. All rights reserved.
Characterization of the aroma profile of Madeira wine by sorptive extraction techniques.
Alves, R F; Nascimento, A M D; Nogueira, J M F
The characterization of the aroma profile of 33 samples of Madeira wine from five monovarieties (Sercial, Verdelho, Boal, Malvasia and Tinta Negra Mole) having different type and categories is presented, using solid phase microextraction and stir bar sorptive extraction techniques (SPME and SBSE) followed by capillary gas chromatography and mass spectrometry detection (GC-MS). Headspace SPME/GC-MS provided effectiveness to identify the major constituents of the aroma profile of Madeira wine, where no remarkable differences occur among the samples studied. The volatile compounds are mainly constituted by ethyl octanoate (11.3-256.9μgL -1 ), ethyl decanoate (21.5-210.5μgL -1 ), ethyl decenoate (0.1-112.8μgL -1 ), diethyl succinate (0.9-65.6μgL -1 ), ethyl dodecanoate (1.2-6.5μgL -1 ), ethyl nonanoate (0.6-5.2μgL -1 ), ethyl hexanoate (0.2-3.7μgL -1 ) and isoamyl octanoate (0-2.2μgL -1 ). C 13 norisoprenoids such as vitispirane (0.9-7.0μgL -1 ) and 1,1,6-trimethyl 1,2-dihydro naphthalene (0.7-12.5μgL -1 ), as well as phenyl ethanol (0-8.1μgL -1 ), were also found in Madeira wine samples. The powerful capabilities of SBSE followed thermal desorption and GC-MS analysis allowed higher ability for profiling traces and ultra traces of compounds in Madeira wine samples, including esters (80.7-89.7%), carboxylic acids (1.6-4.2%), alcohols (3.5-8.2%), aldehydes (0.9-3.7%), pyrans (0.2-1.7%), lactones (sensorial threshold limits. Excellent correlation between Madeira wine ageing and the abundance of cis-oak lactone was attained showing to be an important chemical descriptor to characterize reserves and Vintages as well as a contributor to wine flavour. The differentiation between reserves, dry/medium dry and sweet/medium sweet young wines could be well established by means of chemometric analysis, using particular aroma compounds such as diethyl succinate, cis-oak lactone and ethyl octanoate as discriminating variables.
Water-compatible graphene oxide/molecularly imprinted polymer coated stir bar sorptive extraction of propranolol from urine samples followed by high performance liquid chromatography-ultraviolet detection.
Fan, Wenying; He, Man; You, Linna; Zhu, Xuewei; Chen, Beibei; Hu, Bin
Due to the high selectivity and stability, molecularly imprinted polymers (MIPs) have been successfully applied in stir bar sorptive extraction (SBSE) as a special coating to improve the selective extraction capability for target analytes. However, traditional MIPs usually suffer from incompatibility in aqueous media and low adsorption capacity, which limit the application of MIP coated stir bar in aqueous samples. To solve these problems, a water-compatible graphene oxides (GO)/MIP composite coated stir bar was prepared in this work by in situ polymerization. The prepared water-compatible GO/MIP coated stir bar presented good mechanical strength and chemical stability, and its recognition ability in aqueous samples was improved due to the polymerization of MIP in water environment, the adsorption capacity for target analytes was also increased by the addition of GO in MIP pre-polymer solution. Based on it, a method of water-compatible GO/MIP coated stir bar sorptive extraction combined with high performance liquid chromatography-ultraviolet detector (HPLV-UV) was proposed for the analysis of propranolol (PRO) in aqueous solution. The influencing factors of SBSE, such as sample pH, salt effect, stirring rate, extraction time, desorption solvent and desorption time, were optimized, and the analytical performance of the developed SBSE-HPLC-UV method was evaluated under the optimized conditions. The limit of detection (LOD) of the proposed method for PRO was about 0.37 μg L(-1), and the enrichment factor (EF) was 59.7-fold (theoretical EF was 100-fold). The reproducibility was also investigated at concentrations of 5 μg L(-1) and the relative standard deviation (RSD) was found to be 7.3% (n=7). The proposed method of GO/MIP coating-SBSE-HPLC-UV was successfully applied for the assay of the interested PRO drug in urine samples, and further extended to the investigation of the excretion of the drugs by monitoring the variation of the concentration of PRO in urine
Dual solid-phase and stir bar sorptive extraction combined with gas chromatography-mass spectrometry analysis provides a suitable tool for assaying limonene-derived mint aroma compounds in red wine.
Picard, Magali; Franc, Céline; de Revel, Gilles; Marchand, Stéphanie
A novel analytical method was developed for quantitative determination of eight limonene-derived monoterpenes responsible for the mint aroma in red wine. As these aromatic compounds are present at trace levels, a new dual extraction approach was proposed, combining solid-phase extraction (SPE) and stir bar sorptive extraction (SBSE), followed by gas chromatography-mass spectrometry analysis. The various parameters affecting the efficiency of extracting the analytes from wine samples in both the SPE and SBSE steps were first investigated, to determine the best compromise for the simultaneous analysis of the compounds studied. Following preliminary optimization of the dilution factor, phase ratio, and methanol content in the SBSE sample, cartridge sorbent mass, type of solvent, elution volume, and wine sample volume in the pre-concentration SPE step were studied. Highest response values were obtained when a 90 mL wine sample was extracted on a 500 mg SPE C18 cartridge and eluted with 1.5 mL methanol. The wine extract was then diluted in 10 mL water to obtain a final methanol content of 15% before the SBSE step. Good linearity, repeatability, reproducibility, accuracy and the required low detection and quantification limits were obtained under the conditions described, making this SPE-SBSE combination a suitable, powerful tool for routine analysis of the selected limonene-derived mint aroma compounds in large series of wine samples. Finally, the validated method was applied to 15 commercial red Bordeaux wines, aged from 3 to 23 years. Most of the compounds studied, present within the ng.L -1 range, were easily quantified for the first time in wine. Copyright © 2017 Elsevier B.V. All rights reserved.
A comparison of sorptive extraction techniques coupled to a new quantitative, sensitive, high throughput GC-MS/MS method for methoxypyrazine analysis in wine.
Hjelmeland, Anna K; Wylie, Philip L; Ebeler, Susan E
Methoxypyrazines are volatile compounds found in plants, microbes, and insects that have potent vegetal and earthy aromas. With sensory detection thresholds in the low ng L(-1) range, modest concentrations of these compounds can profoundly impact the aroma quality of foods and beverages, and high levels can lead to consumer rejection. The wine industry routinely analyzes the most prevalent methoxypyrazine, 2-isobutyl-3-methoxypyrazine (IBMP), to aid in harvest decisions, since concentrations decrease during berry ripening. In addition to IBMP, three other methoxypyrazines IPMP (2-isopropyl-3-methoxypyrazine), SBMP (2-sec-butyl-3-methoxypyrazine), and EMP (2-ethyl-3-methoxypyrazine) have been identified in grapes and/or wine and can impact aroma quality. Despite their routine analysis in the wine industry (mostly IBMP), accurate methoxypyrazine quantitation is hindered by two major challenges: sensitivity and resolution. With extremely low sensory detection thresholds (~8-15 ng L(-1) in wine for IBMP), highly sensitive analytical methods to quantify methoxypyrazines at trace levels are necessary. Here we were able to achieve resolution of IBMP as well as IPMP, EMP, and SBMP from co-eluting compounds using one-dimensional chromatography coupled to positive chemical ionization tandem mass spectrometry. Three extraction techniques HS-SPME (headspace-solid phase microextraction), SBSE (stirbar sorptive extraction), and HSSE (headspace sorptive extraction) were validated and compared. A 30 min extraction time was used for HS-SPME and SBSE extraction techniques, while 120 min was necessary to achieve sufficient sensitivity for HSSE extractions. All extraction methods have limits of quantitation (LOQ) at or below 1 ng L(-1) for all four methoxypyrazines analyzed, i.e., LOQ's at or below reported sensory detection limits in wine. The method is high throughput, with resolution of all compounds possible with a relatively rapid 27 min GC oven program. Copyright © 2015
Zirconia coated stir bar sorptive extraction combined with large volume sample stacking capillary electrophoresis-indirect ultraviolet detection for the determination of chemical warfare agent degradation products in water samples.
Li, Pingjing; Hu, Bin; Li, Xiaoyong
In this study, a sensitive, selective and reliable analytical method by combining zirconia (ZrO₂) coated stir bar sorptive extraction (SBSE) with large volume sample stacking capillary electrophoresis-indirect ultraviolet (LVSS-CE/indirect UV) was developed for the direct analysis of chemical warfare agent degradation products of alkyl alkylphosphonic acids (AAPAs) (including ethyl methylphosphonic acid (EMPA) and pinacolyl methylphosphonate (PMPA)) and methylphosphonic acid (MPA) in environmental waters. ZrO₂ coated stir bar was prepared by adhering nanometer-sized ZrO₂ particles onto the surface of stir bar with commercial PDMS sol as adhesion agent. Due to the high affinity of ZrO₂ to the electronegative phosphonate group, ZrO₂ coated stir bars could selectively extract the strongly polar AAPAs and MPA. After systematically optimizing the extraction conditions of ZrO₂-SBSE, the analytical performance of ZrO₂-SBSE-CE/indirect UV and ZrO₂-SBSE-LVSS-CE/indirect UV was assessed. The limits of detection (LODs, at a signal-to-noise ratio of 3) obtained by ZrO₂-SBSE-CE/indirect UV were 13.4-15.9 μg/L for PMPA, EMPA and MPA. The relative standard deviations (RSDs, n=7, c=200 μg/L) of the corrected peak area for the target analytes were in the range of 6.4-8.8%. Enhancement factors (EFs) in terms of LODs were found to be from 112- to 145-fold. By combining ZrO₂ coating SBSE with LVSS as a dual preconcentration strategy, the EFs were magnified up to 1583-fold, and the LODs of ZrO₂-SBSE-LVSS-CE/indirect UV were 1.4, 1.2 and 3.1 μg/L for PMPA, EMPA, and MPA, respectively. The RSDs (n=7, c=20 μg/L) were found to be in the range of 9.0-11.8%. The developed ZrO₂-SBSE-LVSS-CE/indirect UV method has been successfully applied to the analysis of PMPA, EMPA, and MPA in different environmental water samples, and the recoveries for the spiked water samples were found to be in the range of 93.8-105.3%. Copyright © 2012 Elsevier B.V. All rights reserved.
Ultra-trace determination of Persistent Organic Pollutants in Arctic ice using stir bar sorptive extraction and gas chromatography coupled to mass spectrometry.
Lacorte, S; Quintana, J; Tauler, R; Ventura, F; Tovar-Sánchez, A; Duarte, C M
This study presents the optimization and application of an analytical method based on the use of stir bar sorptive extraction (SBSE) gas chromatography coupled to mass spectrometry (GC-MS) for the ultra-trace analysis of POPs (Persistent Organic Pollutants) in Arctic ice. In a first step, the mass-spectrometry conditions were optimized to quantify 48 compounds (polycyclic aromatic hydrocarbons, brominated diphenyl ethers, chlorinated biphenyls, and organochlorinated pesticides) at the low pg/L level. In a second step, the performance of this analytical method was evaluated to determine POPs in Arctic cores collected during an oceanographic campaign. Using a calibration range from 1 to 1800 pg/L and by adjusting acquisition parameters, limits of detection at the 0.1-99 and 102-891 pg/L for organohalogenated compounds and polycyclic aromatic hydrocarbons, respectively, were obtained by extracting 200 mL of unfiltered ice water. alpha-hexachlorocyclohexane, DDTs, chlorinated biphenyl congeners 28, 101 and 118 and brominated diphenyl ethers congeners 47 and 99 were detected in ice cores at levels between 0.5 to 258 pg/L. We emphasise the advantages and disadvantages of in situ SBSE in comparison with traditional extraction techniques used to analyze POPs in ice.
Graphene oxide-coated stir bar sorptive extraction of trace aflatoxins from soy milk followed by high performance liquid chromatography-laser-induced fluorescence detection.
Ma, Haiyan; Ran, Congcong; Li, Mengjiao; Gao, Jinglin; Wang, Xinyu; Zhang, Lina; Bian, Jing; Li, Junmei; Jiang, Ye
Mycotoxins are potential food pollutants produced by fungi. Among them, aflatoxins (AFs) are the most toxic. Therefore, AFs were selected as models, and a sensitive, simple and green graphene oxide (GO)-based stir bar sorptive extraction (SBSE) method was developed for extraction and determination of AFs with high performance liquid chromatography-laser-induced fluorescence detector (HPLC-LIF). This method improved the sensitivity of AFs detection and solved the deposition difficulty of the direct use of GO as adsorbent. Several parameters including a spiked amount of NaCl, stirring rate, extraction time and desorption time were investigated. Under optimal conditions, the quantitative method had low limits of detection of 2.4-8.0 pg/mL, which were better than some reported AFs analytical methods. The developed method has been applied to soy milk samples with good recoveries ranging from 80.5 to 102.3%. The prepared GO-based SBSE can be used as a sensitive screening technique for detecting AFs in soy milk.
Characterisation, quantity and sorptive properties of microplastics extracted from cosmetics.
Napper, Imogen E; Bakir, Adil; Rowland, Steven J; Thompson, Richard C
Cosmetic products, such as facial scrubs, have been identified as potentially important primary sources of microplastics to the marine environment. This study characterises, quantifies and then investigates the sorptive properties of plastic microbeads that are used as exfoliants in cosmetics. Polyethylene microbeads were extracted from several products, and shown to have a wide size range (mean diameters between 164 and 327 μm). We estimated that between 4594 and 94,500 microbeads could be released in a single use. To examine the potential for microbeads to accumulate and transport chemicals they were exposed to a binary mixture of (3)H-phenanthrene and (14)C-DDT in seawater. The potential for transport of sorbed chemicals by microbeads was broadly similar to that of polythene (PE) particles used in previous sorption studies. In conclusion, cosmetic exfoliants are a potentially important, yet preventable source of microplastic contamination in the marine environment. Copyright © 2015 Elsevier Ltd. All rights reserved.
Análise dos produtos de degradação do esfenvalerato por SBSE/CLAE-UV/DAD utilizando planejamento fatorial fracionário
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Renata Colombo
Full Text Available A simple procedure based on stir bar sorptive extraction and high-performance liquid chromatography-ultraviolet/photodiode array detection (SBSE/LC-UV/PAD to determine intermediates and by-products of esfenvalerate is described. The influence of organic modifier, ionic strength, extraction time, temperature and pH were simultaneously evaluated by using a factorial experimental design. The utilization of different organic solvents and desorption times were also investigated to establish the optimal conditions for SBSE liquid desorption. Among the ten different peaks (intermediates and by-products detected after degradation of esfenvalerate, eight (including 3-phenoxybenzoic acid and 3-phenoxybenzaldehyde were successfully extracted by SBSE under the optimized conditions.
Mercury speciation and analysis in drinking water by stir bar sorptive extraction with in situ propyl derivatization and thermal desorption-gas chromatography-mass spectrometry.
Ito, Rie; Kawaguchi, Migaku; Sakui, Norihiro; Honda, Hidehiro; Okanouchi, Noriya; Saito, Koichi; Nakazawa, Hiroyuki
A method for mercury analysis and speciation in drinking water was developed, which involved stir bar sorptive extraction (SBSE) with in situ propyl derivatization and thermal desorption (TD)-GC-MS. Ten millilitre of tap water or bottled water was used. After a stir bar, pH adjustment agent and derivatization reagent were added, SBSE was performed. Then, the stir bar was subjected to TD-GC-MS. The detection limits were 0.01 ng mL(-1) (ethylmercury; EtHg), 0.02 ng mL(-1) (methylmercury; MeHg), and 0.2 ng mL(-1) (Hg(II) and diethylmercury (DiEtHg)). The method showed good linearity and correlation coefficients. The average recoveries of mercury species (n=5) in water samples spiked with 0.5, 2.0, and 6.0 ng mL(-1) mercury species were 93.1-131.1% (RSDmercury species in water samples.
Determination of tributyltin in environmental water matrices using stir bar sorptive extraction with in-situ derivatisation and large volume injection-gas chromatography-mass spectrometry.
Neng, N R; Santalla, R P; Nogueira, J M F
Stir bar sorptive extraction with in-situ derivatization using sodium tetrahydridoborate (NaBH4) followed by liquid desorption and large volume injection-gas chromatography-mass spectrometry detection under the selected ion monitoring mode (SBSE(NaBH4)in-situ-LD/LVI-GC-MS(SIM)) was successfully developed for the determination of tributyltin (TBT) in environmental water matrices. NaBH4 proved to be an effective and easy in-situ speciation agent for TBT in aqueous media, allowing the formation of adducts with enough stability and suitable polarity for SBSE analysis. Assays performed on water samples spiked at the 10.0μg/L, yielded convenient recoveries (68.2±3.0%), showed good accuracy, suitable precision (RSD<9.0%), low detection limits (23ng/L) and excellent linear dynamic range (r(2)=0.9999) from 0.1 to 170.0µg/L, under optimized experimental conditions. By using the standard addition method, the application of the present methodology to real surface water samples allowed very good performance at the trace level. The proposed methodology proved to be a feasible alternative for routine quality control analysis, easy to implement, reliable and sensitive to monitor TBT in environmental water matrices. Copyright © 2014 Elsevier B.V. All rights reserved.
Evaluation of stir-bar sorptive extraction coupled with thermal desorption GC-MS for the detection of leachables from polymer single use systems to drugs.
Scherer, Nicole; Marcseková, Klaudia; Posset, Tobias; Winter, Gerhard
Stir-bar Sorptive Extraction (SBSE) in combination with thermal desorption and gas chromatography-mass spectrometry (TD-GC-MS) is widely accepted as the gold-standard analysis method for trace amounts of organic substances, including leachables in aqueous matrices. Meanwhile, as far as pharmaceutical quality control in protein-based parenteral drugs is concerned, the use of SBSE analysis remains unexplored. Previous studies reported a strong influence of the matrix on the method's recovery. The scope of the present work was to fill in the unexplored territory in a threefold manner 1) by quantifying the effects that various matrices commonly found in pharmaceutical processing have on the recovery, 2) by comparing between different coating materials for stir bar (namely between polydimethylsiloxane (PDMS) material and ethylene-glycol (EG)-PDMS), and 3) by proposing a preparation step for stir-bar to mitigate inhibitory effects. The current study shows no inhibition of SBSE by protein matrices (p > 0.15). Further the influence of various drug matrices on the recovery of leachables with a log K o/w ≥ 3.6 is negligible (-3.9 to 3.8%). In contrast, the inhibition effect caused by an alkaline media led to a recovery decrease of -42.9%. For leachables with a log K o/w 0.992). On average, the conventional PDMS coating resulted in a 28-fold higher signal-to-noise ratio compared to EG-PDMS. Furthermore, a broader range of leachables was detectable with the PDSM coating. Preceding stir-bar preparation consisting of a simple soaking step improved the enrichment by 14%, effectively lowering the limit of detection. Copyright © 2018 Elsevier B.V. All rights reserved.
Polydimethylsiloxane/MIL-100(Fe) coated stir bar sorptive extraction-high performance liquid chromatography for the determination of triazines in environmental water samples.
Lei, Yun; Chen, Beibei; You, Linna; He, Man; Hu, Bin
Polydimethylsiloxane (PDMS)/MIL-100(Fe) coated stir bar was prepared by sol gel technique, and good preparation reproducibility was achieved with relative standard deviations (RSDs) ranging from 2.6% to 7.5% (n=7) and 3.6% to 10.8% (n=7) for bar-to-bar and batch-to-batch, respectively. Compared with commercial PDMS coated stir bar (Gerstel) and PEG coated stir bar (Gerstel), the prepared PDMS/MIL-100(Fe) stir bar showed better extraction efficiency for target triazines compounds. It also exhibited relatively fast extraction/desorption kinetics and long lifespan. Based on it, a method of PDMS/MIL-100(Fe) coated stir bar sorptive extraction (SBSE)-high performance liquid chromatography-ultraviolet detector (HPLC-UV) was developed for the determination of six triazines (simazine, atrazine, prometon, ametryn, prometryne and prebane) in environmental water samples. Several parameters affecting SBSE of six target triazines including extraction time, stirring rate, sample pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) were found to be in the range of 0.021-0.079μgL -1 . The repeatability RSDs were in the range of 2.3-6.3% (n=7, c=0.5μgL -1 ) and the enrichment factors (EFs) ranged from 51.1 to 102-fold (theoretical EF was 200-fold). The proposed method was applied to the analysis of target triazines in environmental water samples, with recoveries of 98.0-118% and 94.0-107% for spiked East Lake water and local pond water samples, respectively. Copyright © 2017. Published by Elsevier B.V.
Polyaniline/cyclodextrin composite coated stir bar sorptive extraction combined with high performance liquid chromatography-ultraviolet detection for the analysis of trace polychlorinated biphenyls in environmental waters.
Lei, Yun; He, Man; Chen, Beibei; Hu, Bin
A novel polyaniline/α-cyclodextrin (PANI/α-CD) composite coated stir bar was prepared by sol-gel process for the analysis of polychlorinated biphenyls (PCBs) in this work. The preparation reproducibility of the PANI/α-CD-coated stir bar was good, with relative standard deviations (RSDs) ranging from 2.3% to 3.7% (n=7) and 2.0% to 3.8% (n=7) for bar to bar and batch to batch, respectively. Based on it, a novel method of PANI/α-CD-coated stir bar sorptive extraction (SBSE) followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection was developed for the determination of trace PCBs in environmental waters. To obtain the best extraction performance for target PCBs, several parameters affecting SBSE, such as extraction time, stirring rate, and ionic strength were investigated. Under optimal experimental conditions, the limits of detection (LODs) of the proposed method for seven PCBs were in the range of 0.048-0.22 μg/L, and the RSDs were 5.3-9.8% (n=7, c=1 μg/L). Enrichment factors (EFs) ranging from 39.8 to 68.4-fold (theoretical EF, 83.3-fold) for target analytes were achieved. The proposed method was successfully applied for the determination of seven target PCBs in Yangtze River water and East Lake water, and the recoveries were in the range of 73.0-120% for the spiked East Lake water samples and 82.7-121% for the spiked Yangtze River water samples, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.
A sublimate sorbent for stir-bar sorptive extraction of aqueous endocrine disruptor pesticides for gas chromatography-electron capture detection.
Huang, Yu-Wen; Lee, Hua Kwang; Shih, Hou-Kuang; Jen, Jen-Fon
A dumbbell-shaped magnetic stir-bar with sublimate sorbent was prepared for the stir bar sorptive extraction (SBSE) of pesticides in an aqueous sample prior to gas chromatography-micro-electron capture detection (GC-μECD). Cyclododecane (CDD) was coated onto a magnetic stir-bar surface as a sublimate sorbent, and steel balls were placed on both ends to form a dumbbell-shaped magnetic stir-bar for SBSE. Four EDC pesticides including chlorpyrifos, ethion, bromopropylate, and λ-cyhalothrin in aqueous samples were selected as model species to examine the proposed SBSE and the following desorption. The parameters studied were those affecting the extraction efficiencies including the coating (solvent for CDD and thickness), extraction (sample pH, stirring rate, time, and salting out effect), dissolution solvent volume, and the loss of CDD sublimated in air. The maximum extraction efficiency was obtained under the following conditions. The stir bar (with CDD thickness of 5.2 μm) was added into a 10 mL sample solution (at pH 7) for a 20-min extraction at 600 rpm. Then, the stir bar was gently removed from the sample solution, disassembled, and immersed into a 0.2 mL insert tube consisting of 3 μL hexane to dissolve; 1 μL was used for GC-ECD analysis. The linear ranges were 0.005-5 μg L -1 with coefficients of determination ranging from 0.9950 - 0.9994. Detection limits (based on S/N = 3) of the four EDCs were 0.4-4.5 ngL -1 with a relative standard deviation (RSD) of 2.4-6.3%, and quantitation limits (based on S/N = 5) were 1-15 ngL -1 . The relative recoveries of the spiked samples were in the range of 83.2-98.7% with RSDs of 2.1-8.4% in farm field waters. The proposed sublimation sorbent obtained excellent enrichment factors (101-834) and provided a simple, rapid, sensitive, and eco-friendly sample preparation method. Copyright © 2018 Elsevier B.V. All rights reserved.
Stir bar sorptive extraction and liquid chromatography-tandem mass spectrometry determination of polar and non-polar emerging and priority pollutants in environmental waters.
Aparicio, Irene; Martín, Julia; Santos, Juan Luis; Malvar, José Luis; Alonso, Esteban
An analytical method based on stir bar sorptive extraction (SBSE) was developed and validated for the determination of environmental concern pollutants in environmental waters by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Target compounds include six water and oil repellents (perfluorinated compounds), four preservatives (butylated hydroxytoluene and three parabens), two plasticizers (bisphenol A and di(2-ethylhexyl)phthalate), seven surfactants (four linear alkylbenzene sulfonates, nonylphenol and two nonylphenol ethoxylates), a flame retardant (hexabromocyclododecane), four hormones, fourteen pharmaceutical compounds, an UV-filter (2-ethylhexyl 4-methoxycinnamate) and nine pesticides. To achieve the simultaneous extraction of polar and non-polar pollutants two stir bar coatings were tested, the classic polydimethylsiloxane (PDMS) coating and the novel ethylene glycol modified silicone (EG-silicone). The best extraction recoveries were obtained using EG-silicone coating. The effects of sample pH, volume and ionic strength and extraction time on extraction recoveries were evaluated. The analytical method was validated for surface water and tap water samples. The method quantification limits ranged from 7.0ngL -1 to 177ngL -1 . The inter-day precision, expressed as relative standard deviation, was lower than 20%. Accuracy, expressed as relative recovery values, was in the range from 61 to 130%. The method was applied for the determination of the 48 target compounds in surface and tap water samples. Copyright © 2017 Elsevier B.V. All rights reserved.
Polydimethylsiloxane/covalent triazine frameworks coated stir bar sorptive extraction coupled with high performance liquid chromatography-ultraviolet detection for the determination of phenols in environmental water samples.
Zhong, Cheng; He, Man; Liao, Huaping; Chen, Beibei; Wang, Cheng; Hu, Bin
In this work, covalent triazine frameworks (CTFs) were introduced in stir bar sorptive extraction (SBSE) and a novel polydimethylsiloxane(PDMS)/CTFs stir bar coating was prepared by sol-gel technique for the sorptive extraction of eight phenols (including phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p-chloro-m-cresol and 2,4-dichlorophenol, 2,4,6-trichlorophenol) from environmental water samples followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection. The prepared PDMS/CTFs coated stir bar showed good preparation reproducibility with the relative standard deviations (RSDs) ranging from 3.5 to 5.7% (n=7) in one batch, and from 3.7 to 9.3% (n=7) among different batches. Several parameters affecting SBSE of eight target phenols including extraction time, stirring rate, sample pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) were found to be in the range of 0.08-0.30 μg/L. The linear range was 0.25-500 μg/L for 2-nitrophenol, 0.5-500 μg/L for phenol, 2-chlorophenol, 4-nitrophenol as well as 2,4-dimethylphenol, and 1-500 μg/L for p-chloro-m-cresol, 2,4-dichlorophenol as well as 2,4,6-trichlorophenol, respectively. The intra-day relative standard deviations (RSDs) were in the range of 4.3-9.4% (n=7, c=2 μg/L) and the enrichment factors ranged from 64.9 to 145.6 fold (theoretical enrichment factor was 200-fold). Compared with commercial PDMS coated stir bar (Gerstel) and PEG coated stir bar (Gerstel), the prepared PDMS/CTFs stir bar showed better extraction efficiency for target phenol compounds. The proposed method was successfully applied to the analysis of phenols in environmental water samples and good relative recoveries were obtained with the spiking level at 2, 10, 50 μg/L, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.
Characterisation of dissolved organic compounds in hydrothermal fluids by stir bar sorptive extraction - gas chomatography - mass spectrometry. Case study: the Rainbow field (36°N, Mid-Atlantic Ridge
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Konn Cecile
Full Text Available Abstract The analysis of the dissolved organic fraction of hydrothermal fluids has been considered a real challenge due to sampling difficulties, complexity of the matrix, numerous interferences and the assumed ppb concentration levels. The present study shows, in a qualitative approach, that Stir Bar Sorptive Extraction (SBSE followed by Thermal Desorption – Gas Chromatography – Mass Spectrometry (TD-GC-MS is suitable for extraction of small sample volumes and detection of a wide range of volatile and semivolatile organic compounds dissolved in hydrothermal fluids. In a case study, the technique was successfully applied to fluids from the Rainbow ultramafic-hosted hydrothermal field located at 36°14'N on the Mid-Atlantic Ridge (MAR. We show that n-alkanes, mono- and poly- aromatic hydrocarbons as well as fatty acids can be easily identified and their retention times determined. Our results demonstrate the excellent repeatability of the method as well as the possibility of storing stir bars for at least three years without significant changes in the composition of the recovered organic matter. A preliminary comparative investigation of the organic composition of the Rainbow fluids showed the great potential of the method to be used for assessing intrafield variations and carrying out time series studies. All together our results demonstrate that SBSE-TD-GC-MS analyses of hydrothermal fluids will make important contributions to the understanding of geochemical processes, geomicrobiological interactions and formation of mineral deposits.
Ionic liquids intercalated in montmorillonite as the sorptive phase for the extraction of low-polarity organic compounds from water by rotating-disk sorptive extraction
Energy Technology Data Exchange (ETDEWEB)
Fiscal-Ladino, Jhon A.; Obando-Ceballos, Mónica; Rosero-Moreano, Milton [Grupo de Investigación en Cromatografía y Técnicas Afines GICTA, Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, Manizales (Colombia); Montaño, Diego F.; Cardona, Wilson; Giraldo, Luis F. [Química de Plantas Colombianas, Instituto de Química, Escuela de Ciencias Exactas y Naturales, Universidad de Antioquia, Calle 70 No. 52-21, A.A, 1226, Medellín (Colombia); Richter, Pablo, E-mail: email@example.com [Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago (Chile)
Montmorillonite (MMT) clays were modified by the intercalation into their galleries of ionic liquids (IL) based on imidazolium quaternary ammonium salts. This new eco-materials exhibited good features for use as a sorptive phase in the extraction of low-polarity analytes from aqueous samples. Spectroscopic analyses of the modified clays were conducted and revealed an increase in the basal spacing and a shifting of the reflection plane towards lower values as a consequence of the effective intercalation of organic cations into the MMT structure. The novel sorbent developed herein was assayed as the sorptive phase in rotating-disk sorptive extraction (RDSE), using polychlorinated biphenyls (PCBs), representative of low-polarity pollutants, as model analytes. The final determination was made by gas chromatography with electron capture detection. Among the synthetized sorptive phases, the selected system for analytical purposes consisted of MMT modified with the 1-hexadecyl-3-methylimidazolium bromide (HDMIM-Br) IL. Satisfactory analytical features were achieved using a sample volume of 5 mL: the relative recoveries from a wastewater sample were higher than 80%, the detection limits were between 3 ng L{sup −1} and 43 ng L{sup −1}, the precision (within-run precision) expressed as the relative standard deviation ranged from 2% to 24%, and the enrichment factors ranged between 18 and 28. Using RDSE, the extraction efficiency achieved for the selected MMT-HDMIM-Br phase was compared with other commercial solid phases/supports, such as polypropylene, polypropylene with 1-octanol (as a supported liquid membrane), octadecyl (C18) and octyl (C8), and showed the highest response for all the studied analytes. Under the optimized extraction conditions, this new device was applied in the analysis of the influent of a wastewater treatment plant in Santiago (Chile), demonstrating its applicability through the good recoveries and precision achieved with real samples
Sorptive extraction using polydimethylsiloxane/metal-organic framework coated stir bars coupled with high performance liquid chromatography-fluorescence detection for the determination of polycyclic aromatic hydrocarbons in environmental water samples.
Hu, Cong; He, Man; Chen, Beibei; Zhong, Cheng; Hu, Bin
In this work, metal-organic frameworks (MOFs, Al-MIL-53-NH₂) were synthesized via the hydrothermal method, and novel polydimethylsiloxane/metal-organic framework (PDMS/MOFs, PDMS/Al-MIL-53-NH₂)-coated stir bars were prepared by the sol-gel technique. The preparation reproducibility of the PDMS/MOFs-coated stir bar was good, with relative standard deviations (RSDs) ranging from 4.8% to 14.9% (n=7) within one batch and from 6.2% to 16.9% (n=6) among different batches. Based on this fact, a new method of PDMS/MOFs-coated stir bar sorptive extraction (SBSE) and ultrasonic-assisted liquid desorption (UALD) coupled with high performance liquid chromatography-fluorescence detection (HPLC-FLD) was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. To obtain the best extraction performance for PAHs, several parameters affecting SBSE, such as extraction time, stirring rate, and extraction temperature, were investigated. Under optimal experimental conditions, wide linear ranges and good RSDs (n=7) were obtained. With enrichment factors (EFs) of 16.1- to 88.9-fold (theoretical EF, 142-fold), the limits of detection (LODs, S/N=3) of the developed method for the target PAHs were found to be in the range of 0.05-2.94 ng/L. The developed method was successfully applied to the analysis of PAHs in Yangtze River and East Lake water samples. Copyright © 2014 Elsevier B.V. All rights reserved.
One-pot synthesis of zeolitic imidazolate framework-8/poly (methyl methacrylate-ethyleneglycol dimethacrylate) monolith coating for stir bar sorptive extraction of phytohormones from fruit samples followed by high performance liquid chromatography-ultraviolet detection.
You, Linna; He, Man; Chen, Beibei; Hu, Bin
In this work, zeolitic imidazolate framework-8 (ZIF-8)/poly (methyl methacrylate-ethyleneglycol dimethacrylate) (MMA-EGDMA) composite monolith was in situ synthesized on stir bar by one-pot polymerization. Compared with the neat monolith, ZIF-8/poly(MMA-EGDMA) composite monolith has larger surface area and pore volume. It also exhibits higher extraction efficiency for target phytohormones than poly(MMA-EGDMA) monolith and commercial polyethylene glycol (PEG) coated stir bar. Based on it, a method of ZIF-8/poly(MMA-EGDMA) monolith coated stir bar sorptive extraction (SBSE)-high performance liquid chromatography-ultraviolet detection (HPLC-UV) was established for the analysis of five phytohormones in apple and pear samples. The developed method exhibited low limits of detection (0.11-0.51μg/L), wide linear range (0.5-500μg/L) and good recoveries (82.7-111%), which demonstrated good application potential of the ZIF-8/monolith coated stir bar in trace analysis of organic compounds. Copyright © 2017 Elsevier B.V. All rights reserved.
Alternative sorptive extraction method for gas chromatography determination of halogenated anisoles in water and wine samples
International Nuclear Information System (INIS)
Montes, R.; Rodriguez, I.; Rubi, E.; Bollain, M.H.; Cela, R.
An alternative sorptive microextraction method for the determination of five halogenated anisoles in water and wine matrices is proposed. Analytes were concentrated in an inexpensive and disposable piece of bulk polydimethylsiloxane (PDMS), desorbed with a small volume of organic solvent, and determined by gas chromatography with electron-capture detection (GC-ECD) or tandem mass spectrometry (GC-MS/MS). The influence of several factors on the efficiency of extraction and desorption steps was investigated in detail and the observed behaviour justified on the basis of thermodynamics and kinetics of the solid-phase microextraction technique. Under optimised conditions, analytes were first extracted in the headspace (HS) mode, at room temperature, for 2.5 h and then desorbed with 1 mL of n-pentane. This extract was further evaporated to 50 μL. The overall extraction yield of the procedure ranged from 40 to 55% and the limits of quantification remained between 0.5 and 20 ng L -1 , depending on the compound considered and the detection technique. Precision and linearity of the method were excellent for all species with both GC-ECD and GC-MS/MS detection. Matrix effects were evaluated with different water and wine samples; moreover, the suitability of the PDMS sorbent for storage of analytes, under different conditions, was demonstrated
Alternative sorptive extraction method for gas chromatography determination of halogenated anisoles in water and wine samples
Energy Technology Data Exchange (ETDEWEB)
Montes, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)], E-mail: firstname.lastname@example.com; Rubi, E.; Bollain, M.H.; Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)
An alternative sorptive microextraction method for the determination of five halogenated anisoles in water and wine matrices is proposed. Analytes were concentrated in an inexpensive and disposable piece of bulk polydimethylsiloxane (PDMS), desorbed with a small volume of organic solvent, and determined by gas chromatography with electron-capture detection (GC-ECD) or tandem mass spectrometry (GC-MS/MS). The influence of several factors on the efficiency of extraction and desorption steps was investigated in detail and the observed behaviour justified on the basis of thermodynamics and kinetics of the solid-phase microextraction technique. Under optimised conditions, analytes were first extracted in the headspace (HS) mode, at room temperature, for 2.5 h and then desorbed with 1 mL of n-pentane. This extract was further evaporated to 50 {mu}L. The overall extraction yield of the procedure ranged from 40 to 55% and the limits of quantification remained between 0.5 and 20 ng L{sup -1}, depending on the compound considered and the detection technique. Precision and linearity of the method were excellent for all species with both GC-ECD and GC-MS/MS detection. Matrix effects were evaluated with different water and wine samples; moreover, the suitability of the PDMS sorbent for storage of analytes, under different conditions, was demonstrated.
Quantitative analysis of perfumes in talcum powder by using headspace sorptive extraction.
Ng, Khim Hui; Heng, Audrey; Osborne, Murray
Quantitative analysis of perfume dosage in talcum powder has been a challenge due to interference of the matrix and has so far not been widely reported. In this study, headspace sorptive extraction (HSSE) was validated as a solventless sample preparation method for the extraction and enrichment of perfume raw materials from talcum powder. Sample enrichment is performed on a thick film of poly(dimethylsiloxane) (PDMS) coated onto a magnetic stir bar incorporated in a glass jacket. Sampling is done by placing the PDMS stir bar in the headspace vial by using a holder. The stir bar is then thermally desorbed online with capillary gas chromatography-mass spectrometry. The HSSE method is based on the same principles as headspace solid-phase microextraction (HS-SPME). Nevertheless, a relatively larger amount of extracting phase is coated on the stir bar as compared to SPME. Sample amount and extraction time were optimized in this study. The method has shown good repeatability (with relative standard deviation no higher than 12.5%) and excellent linearity with correlation coefficients above 0.99 for all analytes. The method was also successfully applied in the quantitative analysis of talcum powder spiked with perfume at different dosages. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Amino modified multi-walled carbon nanotubes/polydimethylsiloxane coated stir bar sorptive extraction coupled to high performance liquid chromatography-ultraviolet detection for the determination of phenols in environmental samples.
Hu, Cong; Chen, Beibei; He, Man; Hu, Bin
In this work, amino modified multi-walled carbon nanotubes/polydimethylsiloxane (multi-walled carbon nanotubes-4,4'-diaminodiphenylmethane/polydimethylsiloxane, MWCNTs-DDM/PDMS) was synthesized, and utilized as a novel coating for stir bar sorptive extraction (SBSE) of seven phenols (phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p-choro-m-cresol and 2,4,6-trichlorphenol) in environmental water and soil samples, followed by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The prepared MWCNTs-DDM/PDMS coated stir bar was characterized and good preparation reproducibility was obtained with the relative standard deviations (RSDs) ranging from 4.7% to 11.3% (n=9) in one batch, and from 4.8% to 13.9% (n=8) among different batches. Several parameters affecting the extraction of seven target phenols by MWCNTs-DDM/PDMS-SBSE including extraction time, stirring rate, pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N=3) were found to be in the range of 0.14μg/L (2-nitrophenol) to 1.76μg/L (phenol) and the limits of quantification (LOQs, S/N=10) were found to be in the range of 0.46μg/L (2-nitrophenol) to 5.8μg/L (phenol). The linear range was 5-1000μg/L for phenol and 4-nitrophenol, 1-1000μg/L for 2-nitrophenol and 2-1000μg/L for other phenols, respectively. The RSDs of the developed method were in the range of 6.2-11.6% (n=8, c=10μg/L) and the enrichment factors were from 6.5 to 62.8-fold (theoretical enrichment factor was 100-fold). The proposed method was successfully applied to the analysis of phenols in environmental water and soil samples, and good recoveries were obtained for the spiked samples. The proposed method is simple, highly sensitive and suitable for the analysis of trace phenols in environmental samples with complex matrix. Copyright © 2013 Elsevier B.V. All rights reserved.
Dynamic fabric phase sorptive extraction for a group of pharmaceuticals and personal care products from environmental waters.
Lakade, Sameer S; Borrull, Francesc; Furton, Kenneth G; Kabir, Abuzar; Marcé, Rosa Maria; Fontanals, Núria
This paper describes for the first time the use of a new extraction technique, based on fabric phase sorptive extraction (FPSE). This new mode proposes the extraction of the analytes in dynamic mode in order to reduce the extraction time. Dynamic fabric phase sorptive extraction (DFPSE) followed by liquid chromatography-tandem mass spectrometry was evaluated for the extraction of a group of pharmaceuticals and personal care products (PPCPs) from environmental water samples. Different parameters affecting the extraction were optimized and best conditions were achieved when 50mL of sample at pH 3 was passed through 3 disks and analytes retained were eluted with 10mL of ethyl acetate. The recoveries were higher than 60% for most of compounds with the exception of the most polar ones (between 8% and 38%). The analytical method was validated with environmental samples such as river water and effluent and influent wastewater, and good performance was obtained. The analysis of samples revealed the presence of some PPCPs at low ngL(-1) concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.
Development of a carbon-nanoparticle-coated stirrer for stir bar sorptive extraction by a simple carbon deposition in flame.
Feng, Juanjuan; Sun, Min; Bu, Yanan; Luo, Chuannan
Stir bar sorptive extraction is an environmentally friendly microextraction technique based on a stir bar with various sorbents. A commercial stirrer is a good support, but it has not been used in stir bar sorptive extraction due to difficult modification. A stirrer was modified with carbon nanoparticles by a simple carbon deposition process in flame and characterized by scanning electron microscopy and energy-dispersive X-ray spectrometry. A three-dimensional porous coating was formed with carbon nanoparticles. In combination with high-performance liquid chromatography, the stir bar was evaluated using five polycyclic aromatic hydrocarbons as model analytes. Conditions including extraction time and temperature, ionic strength, and desorption solvent were investigated by a factor-by-factor optimization method. The established method exhibited good linearity (0.01-10 μg/L) and low limits of quantification (0.01 μg/L). It was applied to detect model analytes in environmental water samples. No analyte was detected in river water, and five analytes were quantified in rain water. The recoveries of five analytes in two samples with spiked at 2 μg/L were in the range of 92.2-106% and 93.4-108%, respectively. The results indicated that the carbon nanoparticle-coated stirrer was an efficient stir bar for extraction analysis of some polycyclic aromatic hydrocarbons. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Determination of semicarbazide in fish by molecularly imprinted stir bar sorptive extraction coupled with high performance liquid chromatography.
Tang, Tang; Wei, Fangdi; Wang, Xu; Ma, Yujie; Song, Yueyue; Ma, Yunsu; Song, Quan; Xu, Guanhong; Cen, Yao; Hu, Qin
A novel molecularly imprinted stir bar (MI-SB) for sorptive extraction of semicarbazide (SEM) was prepared in present paper. The coating of the stir bar was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, dynamic adsorption and static adsorption tests. The saturated adsorption of MI-SB was about 4 times over that of non-imprinted stir bar (NI-SB). The selectivity of MI-SB for SEM was much better than NI-SB. A method to determine SEM was established by coupling MI-SB sorptive extraction with HPLC-UV. The liner range was 1-100ng/mL for SEM with a correlation coefficient of 0.9985. The limit of detection was about 0.59ng/mL, which was below the minimum required performance limit of SEM in meat products regulated by European Union. The method was applied to the determination of SEM in fish samples with satisfactory results. Copyright © 2018 Elsevier B.V. All rights reserved.
Sensitive determination of estrogens in environmental waters treated with polymeric ionic liquid-based stir cake sorptive extraction and liquid chromatographic analysis.
Chen, Lei; Mei, Meng; Huang, Xiaojia; Yuan, Dongxing
A simple, sensitive and environmentally friendly method using polymeric ionic liquid-based stir cake sorptive extraction followed by high performance liquid chromatography with diode array detection (HPLC/DAD) has been developed for efficient quantification of six selected estrogens in environmental waters. To extract trace estrogens effectively, a poly (1-ally-3-vinylimidazolium chloride-co-ethylene dimethacrylate) monolithic cake was prepared and used as the sorbent of stir cake sorptive extraction (SCSE). The effects of preparation conditions of sorbent and extraction parameters of SCSE for estrogens were investigated and optimized. Under optimal conditions, the developed method showed satisfactory analytical performance for targeted analytes. Low limits of detection (S/N=3) and quantification limits (S/N=10) were achieved within the range of 0.024-0.057 µg/L and 0.08-0.19 µg/L, respectively. Good linearity of method was obtained for analytes with the correlation coefficients (R(2)) above 0.99. At the same time, satisfactory method repeatability and reproducibility was achieved in terms of intra- and inter-day precisions, respectively. Finally, the established SCSE-HPLC/DAD method was successfully applied for the determination of estrogens in different environmental water samples. Recoveries obtained for the determination of estrogens in spiked samples ranged from 71.2% to 108%, with RSDs below 10% in all cases. Copyright © 2016 Elsevier B.V. All rights reserved.
Integrated sampling and analysis unit for the determination of sexual pheromones in environmental air using fabric phase sorptive extraction and headspace-gas chromatography-mass spectrometry.
Alcudia-León, M Carmen; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel; Kabir, Abuzar; Furton, Kenneth G
This article presents a novel unit that integrates for the first time air sampling and preconcentration based on the use of fabric phase sorptive extraction principles. The determination of Tuta absoluta sexual pheromone traces in environmental air has been selected as analytical problem. For this aim, a novel laboratory-built unit made up of commercial brass elements as holder of the sol-gel coated fabric extracting phase has been designed and optimized. The performance of the integrated unit was evaluated analyzing environmental air sampled in tomato crops. The unit can work under sampling and analysis mode which eliminates any need for sorptive phase manipulation prior to instrumental analysis. In the sampling mode, the unit can be connected to a sampling pump to pass the air through the sorptive phase at a controlled flow-rate. In the analysis mode, it is placed in the gas chromatograph autosampler without any instrumental modification. It also diminishes the risk of cross contamination between sampling and analysis. The performance of the new unit has been evaluated using the main components of the sexual pheromone of Tuta absoluta [(3E,8Z,11Z)-tetradecatrien-1-yl acetate and (3E,8Z)-tetradecadien-1-yl acetate] as model analytes. The limits of detection for both compounds resulted to be 1.6μg and 0.8μg, respectively, while the precision (expressed as relative standard deviation) was better than 3.7%. Finally, the unit has been deployed in the field to analyze a number of real life samples, some of them were found positive. Copyright © 2017 Elsevier B.V. All rights reserved.
Extraction optimization and pixel-based chemometric analysis of semi-volatile organic compounds in groundwater
DEFF Research Database (Denmark)
Christensen, Peter; Tomasi, Giorgio; Kristensen, Mette
. In this study, we tested the combination of solid phase extraction (SPE) with dispersive liquid-liquid micro extraction (DLLME), or with stir bar sorptive extraction (SBSE), as an extraction method for semi-VOCs in groundwater. Combining SPE with DLLME or SBSE resulted in better separation of peaks...... in an unresolved complex mixture. SPE-DLLME was chosen as the preferred extraction method. SPE-DLLME covered a larger polarity range (logKo/w 2.0-11.2), had higher extraction efficiency at logKo/w 2.0-3.8 and 5.8-11.2, and was faster compared to SPE-SBSE. SPE-DLLME extraction combined with chemical analysis by gas...... chromatography-mass spectrometry (GC-MS) and pixel-based data analysis of summed extraction ion chromatograms (sEICs) was tested as a new method for chemical fingerprinting of semi-VOCs in 15 groundwater samples. The results demonstrate that SPE-DLLME-GC-MS provides an excellent compromise between compound...
Preparation of a novel sorptive stir bar based on vinylpyrrolidone-ethylene glycol dimethacrylate monolithic polymer for the simultaneous extraction of diazepam and nordazepam from human plasma.
Torabizadeh, Mahsa; Talebpour, Zahra; Adib, Nuoshin; Aboul-Enein, Hassan Y
A new monolithic coating based on vinylpyrrolidone-ethylene glycol dimethacrylate polymer was introduced for stir bar sorptive extraction. The polymerization step was performed using different contents of monomer, cross-linker and porogenic solvent, and the best formulation was selected. The quality of the prepared vinylpyrrolidone-ethylene glycol dimethacrylate stir bars was satisfactory, demonstrating good repeatability within batch (relative standard deviation < 3.5%) and acceptable reproducibility between batches (relative standard deviation < 6.0%). The prepared stir bar was utilized in combination with ultrasound-assisted liquid desorption, followed by high-performance liquid chromatography with ultraviolet detection for the simultaneous determination of diazepam and nordazepam in human plasma samples. To optimize the extraction step, a three-level, four-factor, three-block Box-Behnken design was applied. Under the optimum conditions, the analytical performance of the proposed method displayed excellent linear dynamic ranges for diazepam (36-1200 ng/mL) and nordazepam (25-1200 ng/mL), with correlation coefficients of 0.9986 and 0.9968 and detection limits of 12 and 10 ng/mL, respectively. The intra- and interday recovery ranged from 93 to 106%, and the relative standard deviations were less than 6%. Finally, the proposed method was successfully applied to the analysis of diazepam and nordazepam at their therapeutic levels in human plasma. The novelty of this study is the improved polarity of the stir bar coating and its application for the simultaneous extraction of diazepam and its active metabolite, nordazepam in human plasma sample. The method was more rapid than previously reported stir bar sorptive extraction techniques based on monolithic coatings, and exhibited lower detection limits in comparison with similar methods for the determination of diazepam and nordazepam in biological fluids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Rapid monitoring of residual UV-stabilizers in seawater samples from beaches using fabric phase sorptive extraction and UHPLC-MS/MS.
García-Guerra, Romualdo B; Montesdeoca-Esponda, Sarah; Sosa-Ferrera, Zoraida; Kabir, Abuzar; Furton, Kenneth G; Santana-Rodríguez, José Juan
Benzotriazole UV stabilizers (BUVSs) are a group of compounds added to personal care products such as sunscreens, hair dyes, make up formulations, soaps or shampoos, among others. Direct input from beaches or another aquatic recreational areas is the main source of BUVSs incorporation to the environment, where they can be mutagenic, toxic, pseudo-persistent and bioaccumulative. Due to the low levels of concentration of these compounds found in environmental samples, an extraction process is required prior to their determination. Fabric phase sorptive extraction integrates the advanced material properties of sol-gel hybrid inorganic-organic sorbents with flexible, permeable and functionally active fabric substrates, being a highly responsive, efficient and cheap device that also can be reused. In this paper, we applied fabric phase sorptive extraction methodology to analyse six BUVSs in twenty-four seawater samples from different coastal areas of Gran Canaria Island (Spain). It was coupled to ultra high performance liquid chromatography with tandem mass spectrometry in order to achieve a fast, reliable and sensitive separation and determination of the analytes from different simple matrices, regardless of its complexity and composition. Under the optimum conditions, the proposed method provided enrichment factors of 25 times with limits of detection from 1.06 to 8.96 ng L -1 and limits of quantification from 3.54 to 29.9 ng L -1 for the analytes under study in spiked samples. Intra and inter-day relative standard deviations were between 3.97 and 20.8% for all compounds. The application of the optimized methodology to non-spiked seawater samples allows detecting and quantifying the UV 360 in the range from 41.12 to 544.9 ng L -1 . Copyright © 2016 Elsevier Ltd. All rights reserved.
A molecularly imprinted polymer as the sorptive phase immobilized in a rotating disk extraction device for the determination of diclofenac and mefenamic acid in wastewater
International Nuclear Information System (INIS)
Manzo, Valentina; Ulisse, Karla; Rodríguez, Inés; Pereira, Eduardo; Richter, Pablo
The microextraction of diclofenac and mefenamic acid from water samples was performed by using rotating disk sorptive extraction (RDSE) with molecularly imprinted polymer (MIP) as the sorptive phase. The MIP was synthesized from the monomer 1-vinylimidazol (VI) together with the cross-linker divinylbenzene (DVB) using diphenylamine as the template molecule. Scanning electron microscopy (SEM) analyses of the MIP revealed clusters of spherical particles having a narrow size distribution, with diameters of approximately 1 μm. The optimized extraction conditions involved a disk rotation velocity of 3000 rpm, an extraction time of 120 min, a sample volume of 50 mL, and a sample pH of 2 as well as 25 mg of MIP immobilized in the disk. Desorption of the extracted analytes was performed with 5 mL of methanol for 10 min. Analysis by gas chromatography-mass spectrometry (GC–MS) was carried out after derivatization of the analytes with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). Nonmolecularly imprinted polymer (NIP) was also synthesized for comparison. It was observed that under the same conditions, MIP extracted significantly more NSAIDs containing diphenylamine (or part of this molecule) in their structure than NIP. Higher significant differences between MIP and NIP were observed for diclofenac, mefenamic acid and paracetamol, clearly indicating the effect of the template on the extraction. Recoveries of the method were between 100 and 112%, with relative standard deviations of 5–6%. The limits of detection were between 60 and 223 ng L −1 . Water samples from a wastewater treatment plant (WWTP) of Santiago de Chile, were found to contain concentrations of these acidic drugs between 1.6 and 4.3 μg L −1 and between 1.4 and 3.3 μg L −1 in the influent and effluent, respectively. - Highlights: • A MIP immobilized in a rotating disk sucessfully extracts NSAIDs from wastewater. • MIP had remarkably superior binding properties
A molecularly imprinted polymer as the sorptive phase immobilized in a rotating disk extraction device for the determination of diclofenac and mefenamic acid in wastewater
Energy Technology Data Exchange (ETDEWEB)
Manzo, Valentina; Ulisse, Karla [Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, P.O. Box 653, Santiago (Chile); Rodríguez, Inés [Department of Analytical and Inorganic Chemistry, Faculty of Chemical Sciences, University of Concepción (Chile); Pereira, Eduardo, E-mail: email@example.com [Department of Analytical and Inorganic Chemistry, Faculty of Chemical Sciences, University of Concepción (Chile); Richter, Pablo, E-mail: firstname.lastname@example.com [Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, P.O. Box 653, Santiago (Chile)
The microextraction of diclofenac and mefenamic acid from water samples was performed by using rotating disk sorptive extraction (RDSE) with molecularly imprinted polymer (MIP) as the sorptive phase. The MIP was synthesized from the monomer 1-vinylimidazol (VI) together with the cross-linker divinylbenzene (DVB) using diphenylamine as the template molecule. Scanning electron microscopy (SEM) analyses of the MIP revealed clusters of spherical particles having a narrow size distribution, with diameters of approximately 1 μm. The optimized extraction conditions involved a disk rotation velocity of 3000 rpm, an extraction time of 120 min, a sample volume of 50 mL, and a sample pH of 2 as well as 25 mg of MIP immobilized in the disk. Desorption of the extracted analytes was performed with 5 mL of methanol for 10 min. Analysis by gas chromatography-mass spectrometry (GC–MS) was carried out after derivatization of the analytes with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). Nonmolecularly imprinted polymer (NIP) was also synthesized for comparison. It was observed that under the same conditions, MIP extracted significantly more NSAIDs containing diphenylamine (or part of this molecule) in their structure than NIP. Higher significant differences between MIP and NIP were observed for diclofenac, mefenamic acid and paracetamol, clearly indicating the effect of the template on the extraction. Recoveries of the method were between 100 and 112%, with relative standard deviations of 5–6%. The limits of detection were between 60 and 223 ng L{sup −1}. Water samples from a wastewater treatment plant (WWTP) of Santiago de Chile, were found to contain concentrations of these acidic drugs between 1.6 and 4.3 μg L{sup −1} and between 1.4 and 3.3 μg L{sup −1} in the influent and effluent, respectively. - Highlights: • A MIP immobilized in a rotating disk sucessfully extracts NSAIDs from wastewater. • MIP had remarkably superior binding
Preparation of stir cake sorptive extraction based on polymeric ionic liquid for the enrichment of benzimidazole anthelmintics in water, honey and milk samples
Energy Technology Data Exchange (ETDEWEB)
Wang, Yulei [State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Siming Road, P.O. Box 1009, Xiamen 361005 (China); Zhang, Jie [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences (China); Huang, Xiaojia, E-mail: firstname.lastname@example.com [State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Siming Road, P.O. Box 1009, Xiamen 361005 (China); Yuan, Dongxing [State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Siming Road, P.O. Box 1009, Xiamen 361005 (China)
Highlights: • A new polymeric ionic liquid-based monolith was prepared. • The monolith was used as the extractive medium of stir cake sorptive extraction. • The SCSE–AMIIDB can extract benzimidazole anthelmintics (BAs) effectively. • A combination of SCSE–AMIIDB–LD–HPLC/DAD was developed. • The combination was applied to monitor trace BAs in water, milk and honey samples. - Abstract: In this work, a new stir cake sorptive extraction (SCSE) using polymeric ionic liquid monolith as sorbent was prepared. The sorbent was obtained by in situ copolymerization of an ionic liquid, 1-allyl-3-methylimidazolium bis[(trifluoro methyl)sulfonyl]imide (AMII) and divinylbenzene (DB) in the presence of N,N-dimethylformamide. The influence of the content of ionic liquid and the porogen in the polymerization mixture on extraction performance was studied thoroughly. The physicochemical properties of the polymeric ionic liquid were characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. The usefulness of SCSE–AMIIDB was demonstrated by the enrichment of trace benzimidazole anthelmintics. Several parameters affecting the extraction efficiency were investigated, and under the optimized conditions, a simple and effective method for the determination of trace benzimidazoles residues in water, milk and honey samples was established by coupling SCSE–AMIIDB with high performance liquid chromatography/diode array detection (SCSE–AMIIDB–HPLC/DAD). Results indicated that the limits of detection (S/N = 3) for target compounds were 0.020–0.072 μg L{sup −1}, 0.035–0.10 μg L{sup −1} and 0.026–0.076 μg L{sup −1} in water, milk and honey samples, respectively. In addition, an acceptable reproducibility was achieved by evaluating the repeatability and intermediate precision with relative standard deviations (RSD) of less than 9% and 11%, respectively. Finally, the established AMII�
Validated determination of losartan and valsartan in human plasma by stir bar sorptive extraction based on acrylate monolithic polymer, liquid chromatographic analysis and experimental design methodology.
Babarahimi, Vida; Talebpour, Zahra; Haghighi, Farideh; Adib, Nuoshin; Vahidi, Hamed
In our previous work, a new monolithic coating based on vinylpyrrolidone-ethylene glycol dimethacrylate polymer was introduced for stir bar sorptive extraction. The formulation of the prepared vinylpyrrolidone-ethylene glycol dimethacrylate monolithic polymer was optimized and the satisfactory quality of prepared coated stir bar was demonstrated. In this work, the prepared stir bar was utilized in combination with ultrasound-assisted liquid desorption, followed by high-performance liquid chromatography with ultraviolet detection for the simultaneous determination of losartan (LOS) and valsartan (VAS) in human plasma samples. In a comparison study, the extraction efficiency of the prepared stir bar was accompanied much higher extraction efficiency than the two commercial stir bars (polydimethylsiloxand and polyacrylate) for both target compounds. In order to improve the desorption efficiency of LOS and VAS, the best values for effective parameters on desorption step were selected systematically. Also, the effective parameters on extraction step were optimized using a Box-Behnken design. Under the optimum conditions, the analytical performance of the proposed method displayed excellent linear dynamic ranges for LOS (24-1000 ng mL -1 ) and VAS (91-1000 ng mL -1 ), with correlation coefficients of 0.9998 and 0.9971 and detection limits of 7 and 27 ng mL -1 , respectively. The intra- and inter-day recovery ranged from 98 to 117%, and the relative standard deviations were less than 8%. Finally, the proposed technique was successfully applied to the analysis of LOS and VAS at their therapeutic levels in volunteer patient plasma sample. The obtained results were confirmed using liquid chromatography-mass spectrometry. The proposed technique was more rapid than previously reported stir bar sorptive extraction techniques based on monolithic coatings, and exhibited lower detection limits in comparison with similar methods for the determination of LOS and VLS in
Fabric phase sorptive extraction of selected penicillin antibiotic residues from intact milk followed by high performance liquid chromatography with diode array detection.
Samanidou, Victoria; Michaelidou, Katia; Kabir, Abuzar; Furton, Kenneth G
Fabric phase sorptive extraction (FPSE), a novel sorbent-based microextraction method, was evaluated as a simple and rapid strategy for the extraction of four penicillin antibiotic residues (benzylpenicillin, cloxacillin, dicloxacillin and oxacillin) from cows' milk, without prior protein precipitation. Time-consuming solvent evaporation and reconstitution steps were eliminated successfully from the sample preparation workflow. FPSE utilizes a flexible fabric substrate, chemically coated with sol-gel derived, highly efficient, organic-inorganic hybrid sorbent as the extraction medium. Herein short-chain poly(ethylene glycol) provided optimum extraction sensitivity for the selected penicillins, which were analysed using an RP-HPLC method, validated according to the European Decision 657/2002/EC. The limit of quantitation was 10μg/kg for benzylpenicillin, 20μg/kg for cloxacillin, 25μg/kg dicloxacillin and 30μg/kg oxacillin. These are a similar order of magnitude with those reported in the literature and (with the exception of benzylpenicillin) are less than the maximum residue limits (MRL) set by European legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.
Determination of ppq-levels of alkylmethoxypyrazines in wine by stirbar sorptive extraction combined with multidimensional gas chromatography-mass spectrometry.
Wen, Yan; Ontañon, Ignacio; Ferreira, Vicente; Lopez, Ricardo
Alkylmethoxypyrazines are powerful odorants in many food products. A new method for analysing 3-isopropyl-2-methoxypyrazine, 3-s-butyl-2-methoxypyrazine and 3-isobutyl-2-methoxypyrazine has been developed and applied to wine. The analytes were extracted from 5 mL of wine using stirbar sorptive extraction followed by thermal desorption and multidimensional gas chromatography-mass spectrometry analysis in a single oven. The extraction conditions were optimized in order to obtain a high recovery of the 3-alkyl-2-methoxypyrazines (MP). The detection limits of the method in all cases were under 0.08 ng/L, well below the olfactory thresholds of these compounds in wine. The reproducibility of the method was adequate (below 10%), the linearity satisfactory and the recoveries in all cases close to 100%. The method has been applied to the analysis of 111 Spanish and French wine samples. The levels found suggest that MP have a low direct impact on the aroma properties of wines from the regions around the Pyrenean massif. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
Sol-gel-graphene-based fabric-phase sorptive extraction for cow and human breast milk sample cleanup for screening bisphenol A and residual dental restorative material before analysis by HPLC with diode array detection.
Samanidou, Victoria; Filippou, Olga; Marinou, Eirini; Kabir, Abuzar; Furton, Kenneth G
Fabric-phase sorptive extraction has already been recognized as a simple and green alternative to the conventional sorbent-based sorptive microextraction techniques, using hybrid organic-inorganic sorbent coatings chemically bonded to a flexible fabric surface. Herein, we have investigated the synergistic combination of the advanced material properties offered by sol-gel graphene sorbent and the simplicity of Fabric phase sorptive extraction approach in selectively extracting bisphenol A and residual monomers including bisphenol A glycerolatedimethacrylate, urethane dimethacrylate, and triethylene glycol dimethacrylate derived dental restorative materials from cow and human breast milk samples. Different coatings were evaluated. Final method development employed sol-gel graphene coated media. The main experimental parameters influencing extraction of the compounds, such as sorbent chemistry used, sample loading conditions, elution solvent, sorption stirring time, elution time, impact of protein precipitation, amount of sample, and matrix effect, were investigated and optimized. Absolute recovery values from standard solutions were 50% for bisphenol A, 78% for T triethylene glycol dimethacrylate, 110% for urethane dimethacrylate, and 103% for bisphenol A glycerolatedimethacrylate, while respective absolute recovery values from milk were 30, 52, 104, and 42%. Method validation was performed according to European Decision 657/2002/EC in terms of selectivity, sensitivity, linearity, accuracy, and precision. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.
Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G
A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. Copyright © 2016 Elsevier B.V. All rights reserved.
Non-Destructive Assessment of Aroma Volatiles from a Climacteric Near-Isogenic Line of Melon Obtained by Headspace Stir-Bar Sorptive Extraction
Directory of Open Access Journals (Sweden)
Juan Pablo Fernández-Trujillo
Full Text Available A climacteric aromatic near-isogenic line (NIL of melon (Cucumis melo L. SC3-5-1 contained an introgression of the non-climacteric Korean cultivar "Shongwan Charmi" accession PI 161375 (SC in the genetic background of the non-climacteric cultivar "Piel de Sapo" (PS. The aroma production was monitored during ripening at 21 °C in intact fruit using headspace sorptive bar extraction (HSSE. Bars were composed of polydimethylsiloxane (PDMS and aromas were desorbed and analyzed by gas-chromatography mass-spectrometry. The aromatic profile was composed of 70 aromatic compounds plus 21 alkanes with a predominance of esters, particularly acetate (2-methylbutyl acetate, 2-methylpropyl acetate, hexyl acetate, and phenylmethyl acetate. Some compounds were severely affected by postharvest time. The acetate esters (3-methylbutyl acetate, butan-2-yl acetate and phenylmethyl acetate decreased with ripening and sulfur-derived compounds (S-methyl butanethioate and S-methyl 3-methylbutanethioate increased gradually with ripening. A few compounds increased at the senescence phase (propyl ethanoate. Other compounds such as hexadecanoic acid showed a marked decrease after harvest, some decreasing from a relative maximum at harvest (2-methylpropyl hexanoate; n-hexanoic acid; nonanoic acid.
Time since discharge of 9mm cartridges by headspace analysis, part 1: Comprehensive optimisation and validation of a headspace sorptive extraction (HSSE) method.
Gallidabino, M; Romolo, F S; Weyermann, C
Estimating the time since discharge of spent cartridges can be a valuable tool in the forensic investigation of firearm-related crimes. To reach this aim, it was previously proposed that the decrease of volatile organic compounds released during discharge is monitored over time using non-destructive headspace extraction techniques. While promising results were obtained for large-calibre cartridges (e.g., shotgun shells), handgun calibres yielded unsatisfying results. In addition to the natural complexity of the specimen itself, these can also be attributed to some selective choices in the methods development. Thus, the present series of paper aimed to more systematically evaluate the potential of headspace analysis to estimate the time since discharge of cartridges through the use of more comprehensive analytical and interpretative techniques. Specifically, in this first part, a method based on headspace sorptive extraction (HSSE) was comprehensively optimised and validated, as the latter recently proved to be a more efficient alternative than previous approaches. For this purpose, 29 volatile organic compounds were preliminary selected on the basis of previous works. A multivariate statistical approach based on design of experiments (DOE) was used to optimise variables potentially involved in interaction effects. Introduction of deuterated analogues in sampling vials was also investigated as strategy to account for analytical variations. Analysis was carried out by selected ion mode, gas chromatography coupled to mass spectrometry (GC-MS). Results showed good chromatographic resolution as well as detection limits and peak area repeatability. Application to 9mm spent cartridges confirmed that the use of co-extracted internal standards allowed for improved reproducibility of the measured signals. The validated method will be applied in the second part of this work to estimate the time since discharge of 9mm spent cartridges using multivariate models. Copyright �
Ultra-trace determination of Persistent Organic Pollutants in Artic ice using stir bar sorptive extraction and gas chromatography coupled to mass spectrometry
Lacorte Bruguera, Silvia; Quintana, Jordi; Tauler, Romà; Ventura, Francesc; Tovar-Sánchez, Antonio; Duarte, Carlos M.
This study presents the optimization and application of an analytical method based on the use of stirbarsorptiveextraction (SBSE) gaschromatographycoupled to massspectrometry (GC–MS) for the ultra-trace analysis of POPs (PersistentOrganicPollutants) in Arctic ice. In a first step, the mass-spectrometry conditions were optimized to quantify 48 compounds (polycyclic aromatic hydrocarbons, brominated diphenyl ethers, chlorinated biphenyls, and organochlorinated pesticides) at the low pg/L level....
Preparation of a polymeric ionic liquid-based adsorbent for stir cake sorptive extraction of preservatives in orange juices and tea drinks
Energy Technology Data Exchange (ETDEWEB)
Chen, Lei; Huang, Xiaojia, E-mail: email@example.com
In this study, a new polymeric ionic liquid-based adsorbent was prepared and used as the extraction medium of stir cake sorptive extraction (SCSE) of three organic acid preservatives, namely, p-hydroxybenzoic acid, sorbic acid and cinnamic acid. The adsorbent was synthesized by the copolymerization of 1-ally-3-vinylimidazolium chloride (AV) and divinylbenzene (DVB) in the presence of a porogen solvent containing 1-propanol and 1,4-butanediol. The effect of the content of monomer and the porogen solvent in the polymerization mixture on the extraction performance was investigated thoroughly. The adsorbent was characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. To obtain the optimal extraction conditions of SCSE/AVDVB for target analytes, key parameters including desorption solvent, adsorption and desorption time, ionic strength and pH value in sample matrix were studied in detail. The results showed that under the optimized conditions, the SCSE/AVDVB could extract the preservatives effectively through multiply interactions. At the same time, a simple and sensitive method by combining SCSE/AVDVB and high-performance liquid chromatography with diode array detection was developed for the simultaneous analysis of the target preservatives in orange juices and tea drinks. Low limits of detection (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target analytes were achieved within the range of 0.012–0.23 μg/L and 0.039–0.42 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation (RSD), and it was found that the values were all below 10%. Finally, the proposed method was used to detect preservatives in different orange juice and tea drink samples successfully. The recoveries were in the range of 71.9–116%, and the RSDs were below 10% in the all cases
Preparation of a polymeric ionic liquid-based adsorbent for stir cake sorptive extraction of preservatives in orange juices and tea drinks
International Nuclear Information System (INIS)
Chen, Lei; Huang, Xiaojia
In this study, a new polymeric ionic liquid-based adsorbent was prepared and used as the extraction medium of stir cake sorptive extraction (SCSE) of three organic acid preservatives, namely, p-hydroxybenzoic acid, sorbic acid and cinnamic acid. The adsorbent was synthesized by the copolymerization of 1-ally-3-vinylimidazolium chloride (AV) and divinylbenzene (DVB) in the presence of a porogen solvent containing 1-propanol and 1,4-butanediol. The effect of the content of monomer and the porogen solvent in the polymerization mixture on the extraction performance was investigated thoroughly. The adsorbent was characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. To obtain the optimal extraction conditions of SCSE/AVDVB for target analytes, key parameters including desorption solvent, adsorption and desorption time, ionic strength and pH value in sample matrix were studied in detail. The results showed that under the optimized conditions, the SCSE/AVDVB could extract the preservatives effectively through multiply interactions. At the same time, a simple and sensitive method by combining SCSE/AVDVB and high-performance liquid chromatography with diode array detection was developed for the simultaneous analysis of the target preservatives in orange juices and tea drinks. Low limits of detection (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target analytes were achieved within the range of 0.012–0.23 μg/L and 0.039–0.42 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation (RSD), and it was found that the values were all below 10%. Finally, the proposed method was used to detect preservatives in different orange juice and tea drink samples successfully. The recoveries were in the range of 71.9–116%, and the RSDs were below 10% in the all cases
Optimisation of supercritical fluid extraction of polycyclic aromatic hydrocarbons and their nitrated derivatives adsorbed on highly sorptive diesel particulate matter
International Nuclear Information System (INIS)
Portet-Koltalo, F.; Oukebdane, K.; Dionnet, F.; Desbene, P.L.
Supercritical fluid extraction (SFE) was performed to extract complex mixtures of polycyclic aromatic hydrocarbons (PAHs), nitrated derivatives (nitroPAHs) and heavy n-alkanes from spiked soot particulates that resulted from the incomplete combustion of diesel oils. This polluted material, resulting from combustion in a light diesel engine and collected at high temperature inside the particulate filter placed just after the engine, was particularly resistant to conventional extraction techniques, such as soxhlet extraction, and had an extraction behaviour that differed markedly from certified reference materials (SRM 1650). A factorial experimental design was performed, simultaneously modelling the influence of four SFE experimental factors on the recovery yields, i.e.: the temperature and the pressure of the supercritical fluid, the nature and the percentage of the organic modifier added to CO 2 (chloroform, tetrahydrofuran, methylene chloride), as a means to reach the optimal extraction yields for all the studied target pollutants. The results of modelling showed that the supercritical fluid pressure had to be kept at its maximum level (30 MPa) and the temperature had to be kept relatively low (75 o C). Under these operating conditions, adding 15% of methylene chloride to the CO 2 permitted quantitative extraction of not only light PAHs and their nitrated derivatives, but also heavy n-alkanes from the spiked soots. However, heavy polyaromatics were not quantitatively extracted from the refractory carbonaceous solid surface. As such, original organic modifiers were tested, including pyridine, which, as a strong electron donor cosolvent (15% into CO 2 ), was the most successful. The addition of diethylamine to pyridine, which enhanced the electron donor character of the cosolvent, even increased the extraction yields of the heaviest PAHs, leading to a quantitative extraction of all PAHs (more than 79%) from the diesel particulate matter, with detection limits
Innovative sampling and extraction methods for the determination of nonsteroidal anti-inflammatory drugs in water.
Tanwar, Shivani; Di Carro, Marina; Magi, Emanuele
Two different innovative approaches were used for the determination of nonsteroidal anti-inflammatory drugs (NSAIDs) in water: stir bar sorptive extraction (SBSE) and passive sampling, followed by electrospray ionization liquid chromatography-tandem mass spectrometry. SBSE was developed by comparing EG-Silicone and PDMS stir bars and optimizing main parameters to attain high preconcentration. Quantitative analysis was carried out by mass spectrometry in negative ionization mode and multiple reaction monitoring. The SBSE-LC-MS/MS method provided satisfactory figures of merit with LOD (7.5-71 ng L(-1)) and LOQ (22.5-213 ng L(-1)). The developed method was successfully applied to real samples collected from river water and wastewater effluents. The obtained results showed the presence of all analytes at trace levels, in a wide range of concentrations. The passive sampling approach was carried out by using Polar Organic Chemical Integrative Sampler (POCIS); samplers were deployed for 15 days in river and tap water, allowing to detect analytes at ultra-trace levels. Time-Weighted Average concentration of NSAIDs in river water was estimated in the range 0.33-0.46 ng L(-1), using the sampling rates previously obtained by means of a simple calibration system. Copyright © 2014 Elsevier B.V. All rights reserved.
Volatile profile characterisation of Chilean sparkling wines produced by traditional and Charmat methods via sequential stir bar sorptive extraction.
Ubeda, C; Callejón, R M; Troncoso, A M; Peña-Neira, A; Morales, M L
The volatile compositions of Charmat and traditional Chilean sparkling wines were studied for the first time. For this purpose, EG-Silicone and PDMS polymeric phases were compared and, afterwards, the most adequate was selected. The best extraction method turned out to be a sequential extraction in the headspace and by immersion using two PDMS twisters. A total of 130 compounds were determined. In traditional Chilean sparkling wines, ethyl esters were significantly higher, while acetic esters and ketones were predominant in the Charmat wines. PCA and LDA confirmed the differences in the volatile profiles between the production methods (traditional vs. Charmat). Copyright © 2016 Elsevier Ltd. All rights reserved.
Molecularly imprinted polymers based stir bar sorptive extraction for determination of cefaclor and cefalexin in environmental water.
Peng, Jun; Liu, Donghao; Shi, Tian; Tian, Huairu; Hui, Xuanhong; He, Hua
Although stir bar sportive extraction was thought to be a highly efficiency and simple pretreatment approach, its wide application was limited by low selectivity, short service life, and relatively high cost. In order to improve the performance of the stir bar, molecular imprinted polymers and magnetic carbon nanotubes were combined in the present study. In addition, two monomers were utilized to intensify the selectivity of molecularly imprinted polymers. Fourier transform infrared spectroscopy, scanning electron microscopy, and selectivity experiments showed that the molecularly imprinted polymeric stir bar was successfully prepared. Then micro-extraction based on the obtained stir bar was coupled with HPLC for determination of trace cefaclor and cefalexin in environmental water. This approach had the advantages of stir bar sportive extraction, high selectivity of molecular imprinted polymers, and high sorption efficiency of carbon nanotubes. To utilize this pretreatment approach, pH, extraction time, stirring speed, elution solvent, and elution time were optimized. The LOD and LOQ of cefaclor were found to be 3.5 ng · mL -1 and 12.0 ng · mL -1 , respectively; the LOD and LOQ of cefalexin were found to be 3.0 ng · mL -1 and 10.0 ng · mL -1 , respectively. The recoveries of cefaclor and cefalexin were 86.5 ~ 98.6%. The within-run precision and between-run precision were acceptable (relative standard deviation bar did not decrease dramatically. This demonstrated that the molecularly imprinted polymeric stir bar based micro-extraction was a convenient, efficient, low-cost, and a specific method for enrichment of cefaclor and cefalexin in environmental samples.
Retention model for sorptive extraction-thermal desorption of aqueous samples : application to the automated analysis of pesticides and polyaromatic hydrocarbons in water samples
Baltussen, H.A.; David, F.; Sandra, P.J.F.; Janssen, J.G.M.; Cramers, C.A.M.G.
In this report, an automated method for sorptive enrichment of aqueous samples is presented. It is based on sorption of the analytes of interest into a packed bed containing 100% polydimethylsiloxane (PDMS) particles followed by thermal desorption for complete transfer of the enriched solutes onto
Thermoelectric and mechanical properties of spark plasma sintered Cu3SbSe3 and Cu3SbSe4: Promising thermoelectric materials
Tyagi, Kriti; Gahtori, Bhasker; Bathula, Sivaiah; Toutam, Vijaykumar; Sharma, Sakshi; Singh, Niraj Kumar; Dhar, Ajay
We report the synthesis of thermoelectric compounds, Cu3SbSe3 and Cu3SbSe4, employing the conventional fusion method followed by spark plasma sintering. Their thermoelectric properties indicated that despite its higher thermal conductivity, Cu3SbSe4 exhibited a much larger value of thermoelectric figure-of-merit as compared to Cu3SbSe3, which is primarily due to its higher electrical conductivity. The thermoelectric compatibility factor of Cu3SbSe4 was found to be ˜1.2 as compared to 0.2 V-1 for Cu3SbSe3 at 550 K. The results of the mechanical properties of these two compounds indicated that their microhardness and fracture toughness values were far superior to the other competing state-of-the-art thermoelectric materials.
Preparation of stir cake sorptive extraction based on poly(4-vinylbenzoic acid-divinylbenzene) monolith and its application in sensitive determination of β-agonists in milk and swine urine samples
Energy Technology Data Exchange (ETDEWEB)
Huang, Xiaojia, E-mail: firstname.lastname@example.com; Chen, Linli; Yuan, Dongxing
Highlights: • A new poly(4-vinylbenzoic acid-divinylbenzene) monolith was first prepared. • The porous monolith was used as sorbent of stir cake sorptive extraction. • The new sorbent could extract β-agonists effectively by multiple interactions. • Method of determination of trace β-agonists in milk and urine samples was developed. -- Abstract: In this study, a new stir cake sorptive extraction (SCSE) based on poly(4-vinylbenzoic acid-divinylbenzene) (VBADB) monolith was prepared. The effect of preparation conditions of monolith on extraction efficiencies was investigated in detail. Several characteristic techniques, such as elemental analysis, infrared spectroscopy, mercury intrusion porosimetry and scanning electron microscopy were used to characterize the monolithic material. The combination of SCSE-VBADB with high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS) detection was developed for sensitive determination of ultra-trace β-agonists in milk and swine urine samples. In order to obtain the optimal extraction conditions of SCSE-VBADB for β-agonists, several extractive parameters, including pH values and ionic strength in sample matrix, extraction and desorption time were optimized. Under the optimum conditions, the limits of detection (S/N = 3) for the target analytes were 0.007–0.030 μg/L in milk and 0.002–0.011 μg/L in swine urine, respectively. Excellent method reproducibility was achieved in terms of intraday and interday precisions, indicated by the RSDs of both <10.0%, respectively. Finally, the proposed method was successfully used to detect β-agonists in different milk and swine urines samples. Acceptable recoveries ranged from 50.3% to 113% and 50.1% to 92.2% for milk and swine urine samples, respectively; and the RSDs for reproducibility were less than 8.0% for target analytes in all real samples.
Cadmium (II) imprinted 3-mercaptopropyltrimethoxysilane coated stir bar for selective extraction of trace cadmium from environmental water samples followed by inductively coupled plasma mass spectrometry detection
Energy Technology Data Exchange (ETDEWEB)
Zhang Nan [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Hu Bin, E-mail: email@example.com [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China)
Graphical abstract: Ion imprinted 3-mercaptopropyltrimethoxysilane (MPTS) coated stir bar for selective extraction of trace Cd(II). Highlights: Black-Right-Pointing-Pointer Ion imprinted polymers were proposed as the coating for SBSE for the first time. Black-Right-Pointing-Pointer Cd(II) imprinted MPTS-silica coating was prepared by a double-imprinting concept. Black-Right-Pointing-Pointer A novel method of SBSE-ICP-MS was developed for the determination of Cd in waters. Black-Right-Pointing-Pointer This method is rapid, selective, sensitive and applicable for determining trace Cd(II) in waters. - Abstract: Cd(II) imprinted 3-mercaptopropyltrimethoxysilane (MPTS)-silica coated stir bar was prepared by sol-gel technique combining with a double-imprinting concept for the first time and was employed for stir bar sorptive extraction (SBSE) of trace Cd(II) from water samples followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. A tetramethoxysilane (TMOS) coating was first in situ created on the glass bar surface. Afterward, a sol solution containing MPTS as the functional precursor, ethanol as the solvent and both Cd(II) and surfactant micelles (cetyltrimethylammonium bromide, CTAB) as the template was again coated on the TMOS bar. The structures of the stir bar coating were characterized by FT-IR spectroscopy. Round-bottom vial was used for the extraction of Cd(II) by SBSE to avoid abrasion of stir bar coatings. The factors affecting the extraction of Cd(II) by SBSE such as pH, stirring rate and time, sample/elution volume and interfering ions have been investigated in detail, and the optimized experimental parameters were obtained. Under the optimized conditions, the adsorption capacities of non-imprinted and imprinted coating stir bars were found to be 0.5 {mu}g and 0.8 {mu}g bar{sup -1}. The detection limit (3{sigma}) based on three times standard deviations of the method blanks by 7 replicates was 4.40 ng L{sup -1} and the relative standard
Headspace sorptive solid phase microextraction (HS-SPME) combined with a spectrophotometry system: A simple glass devise for extraction and simultaneous determination of cyanide and thiocyanate in environmental and biological samples.
Al-Saidi, H M; Al-Harbi, Sami A; Aljuhani, E H; El-Shahawi, M S
A simple, low cost and efficient headspace sorptive solid phase microextraction (HS-SPME) method for determination of cyanide has been developed. The system comprises of a glass tube with two valves and a moveable glass slide fixed at its centre. It includes an acceptor phase polyurethane foam treated mercury (II) dithizonate [Hg(HDz)2-PUF] complex fixed inside by a septum cap in a cylindrical configuration (5.0cm length and 1.0cm diameter). The extraction is based upon the contact of the acceptor phase to the headspace and subsequently measuring the absorbance of the recovered mercury (II) dithizonate from PUFs sorbent. Unlike other HSSE, extraction and back - extractions was carried out in a closed system, thereby improving the analytical performance by preventing the analyte loss. Under the optimized conditions, a linear calibration plot in the range of 1.0-50.0µmolL(-1) was achieved with limits of detection (LOD) and quantification (LOQ) of 0.34, 1.2µmolL(-1) CN(-), respectively. Simultaneous analysis of cyanide and thiocyanate in saliva was also performed with satisfactory recoveries. Copyright © 2016. Published by Elsevier B.V.
Fabric phase sorptive extraction-high performance liquid chromatography-photo diode array detection method for simultaneous monitoring of three inflammatory bowel disease treatment drugs in whole blood, plasma and urine.
Kabir, Abuzar; Furton, Kenneth G; Tinari, Nicola; Grossi, Laurino; Innosa, Denise; Macerola, Daniela; Tartaglia, Angela; Di Donato, Valentina; D'Ovidio, Cristian; Locatelli, Marcello
This paper reports a novel fabric phase sorptive extraction-high performance liquid chromatography-photodiode array detection (FPSE-HPLC-PDA) method for the simultaneous extraction and analysis of three drug residues (ciprofloxacin, sulfasalazine, and cortisone) in human whole blood, plasma, and urine samples, generally administered in human patients to treat inflammatory bowel disease (IBD). The drugs of interest were well resolved using a Luna C 18 column (250 mm × 4.6 mm; 5 μm particle size) in gradient elution mode within 20 min. The analytical method was optimized and validated in the range 0.05-10 μg/mL for whole blood, 0.25-10 μg/mL for human plasma, and 0.10-10 μg/mL for human urine. Blank human whole blood, plasma, and urine were used as the sample matrix for the method development and validation; while methyl-p-hydroxybenzoate was used as the internal standard (IS). Weighted-matrix matched standard calibration curves showed a good linearity up to a concentration of 10 μg/mL. The intra- and inter-day accuracy values (precision and trueness) were found in the range from -10.9% to 12.3%, and the performances of the validated FPSE-HPLC-PDA were further tested on real IBD patient samples. This is the first FPSE procedure applied simultaneously to whole blood, plasma, and urine samples for the determination of residual IBD drugs, which possess a wide range of polarity (logP values ranging from 2.30 for Ciprofloxacin, to 1.66 for Cortisone, and 2.92 for Sulfasalazine). The new approach exhibits high potential for immediate adoptation as a rapid, robust and green analytical tool for future clinical and pharmaceutical applications. Copyright © 2018 Elsevier B.V. All rights reserved.
A fabric phase sorptive extraction-High performance liquid chromatography-Photo diode array detection method for the determination of twelve azole antimicrobial drug residues in human plasma and urine.
Locatelli, Marcello; Kabir, Abuzar; Innosa, Denise; Lopatriello, Teresa; Furton, Kenneth G
This paper reports a novel fabric phase sorptive extraction-high performance liquid chromatography-photodiode array detection (FPSE-HPLC-PDA) method for the simultaneous extraction and analysis of twelve azole antimicrobial drug residues that include ketoconazole, terconazole, voriconazole, bifonazole, clotrimazole, tioconazole, econazole, butoconazole, miconazole, posaconazole, ravuconazole, and itraconazole in human plasma and urine samples. The selected azole antimicrobial drugs were well resolved by using a Luna C 18 column (250mm×4.6mm; 5μm particle size) in gradient elution mode within 36min. The analytical method was calibrated and validated in the range from 0.1 to 8μg/mL for all the drug compounds. Blank human plasma and urine were used as the sample matrix for the analysis; while benzyl-4-hydroxybenzoate was used as the internal standard (IS). The limit of quantification of the FPSE-HPLC-PDA method was found as 0.1μg/mL and the weighted-matrix matched standard calibration curves of the drugs showed a good linearity upto a concentration of 8μg/mL. The parallelism tests were also performed to evaluate whether overrange sample can be analyzed after dilution, without compromising the analytical performances of the validated method. The intra- and inter-day precision (RSD%) values were found ≤13.1% and ≤13.9%, respectively. The intra- and inter-day trueness (bias%) values were found in the range from -12.1% to 10.5%. The performances of the validated FPSE-HPLC-PDA were further tested on real samples collected from healthy volunteers after a single dose administration of itraconazole and miconazole. To the best of our knowledge, this is the first FPSE extraction procedure applied on plasma and urine samples for the simultaneous determination of twelve azole drugs possessing a wide range of logK ow values (extending from 0.4 for fluconazole to 6.70 of butoconazole) and could be adopted as a rapid and robust green analytical tool for clinical and
Cadmium (II) imprinted 3-mercaptopropyltrimethoxysilane coated stir bar for selective extraction of trace cadmium from environmental water samples followed by inductively coupled plasma mass spectrometry detection
International Nuclear Information System (INIS)
Zhang Nan; Hu Bin
Graphical abstract: Ion imprinted 3-mercaptopropyltrimethoxysilane (MPTS) coated stir bar for selective extraction of trace Cd(II). Highlights: ► Ion imprinted polymers were proposed as the coating for SBSE for the first time. ► Cd(II) imprinted MPTS-silica coating was prepared by a double-imprinting concept. ► A novel method of SBSE–ICP-MS was developed for the determination of Cd in waters. ► This method is rapid, selective, sensitive and applicable for determining trace Cd(II) in waters. - Abstract: Cd(II) imprinted 3-mercaptopropyltrimethoxysilane (MPTS)-silica coated stir bar was prepared by sol–gel technique combining with a double-imprinting concept for the first time and was employed for stir bar sorptive extraction (SBSE) of trace Cd(II) from water samples followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. A tetramethoxysilane (TMOS) coating was first in situ created on the glass bar surface. Afterward, a sol solution containing MPTS as the functional precursor, ethanol as the solvent and both Cd(II) and surfactant micelles (cetyltrimethylammonium bromide, CTAB) as the template was again coated on the TMOS bar. The structures of the stir bar coating were characterized by FT-IR spectroscopy. Round-bottom vial was used for the extraction of Cd(II) by SBSE to avoid abrasion of stir bar coatings. The factors affecting the extraction of Cd(II) by SBSE such as pH, stirring rate and time, sample/elution volume and interfering ions have been investigated in detail, and the optimized experimental parameters were obtained. Under the optimized conditions, the adsorption capacities of non-imprinted and imprinted coating stir bars were found to be 0.5 μg and 0.8 μg bar −1 . The detection limit (3σ) based on three times standard deviations of the method blanks by 7 replicates was 4.40 ng L −1 and the relative standard deviation (RSD) was 3.38% (c = 1 μg L −1 , n = 7). The proposed method was successfully applied for the
Examination of Some Commercial Sorptive Organobentonites
ÖNAL, Müşerref
For controlling organophilic partition nanophase (OPN) formation in some commercial sorptive organobentonites (OBs), 4 sample were selected randomly and examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential thermal analysis (DTA), thermal gravimetric analysis (TGA), element analysis (EA), and nitrogen adsorption/desorption (N2-AD) techniques. Since the d(001) values of the OB samples are between 1.94 and 3.36 nm, the pseudotrilayer or paraff...
Enhanced electrical transport and thermoelectric properties in Ni doped Cu3SbSe4
Kumar, Aparabal; Dhama, P.; Das, Anish; Sarkar, Kalyan Jyoti; Banerji, P.
In this study, we report the enhanced thermoelectric performance of Cu3SbSe4 by Ni doping at Cu site. Cu3-xNixSbSe4 (x = 0, 0.01, 0.03, 0.05) were prepared by melt growth, ball milling followed by spark plasma sintering. Structural characterization, phase analysis and surface morphology were carried out using X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Electrical and thermal properties of all the samples were investigated in the temperature range 300 - 650 K. Decrease in electrical resistivity with Ni doping due to increase in carrier concentration with enhanced Seebeck coefficient via increase in density of state near the Fermi level gives a remarkably high power factor. At the same time, thermal conductivity was found to decrease due to increased carrier-phonon scattering and acoustic phonon scattering. Consequently, a remarkable enhancement in the thermoelectric figure of merit (ZT˜ 0.65) of Cu3-xNixSbSe4 was achieved for x = 0.01 sample. Thus, Ni doping is an effective approach to improve the efficiency of Cu3SbSe4.
Acoustics of multiscale sorptive porous materials
Venegas, R.; Boutin, C.; Umnova, O.
This paper investigates sound propagation in multiscale rigid-frame porous materials that support mass transfer processes, such as sorption and different types of diffusion, in addition to the usual visco-thermo-inertial interactions. The two-scale asymptotic method of homogenization for periodic media is successively used to derive the macroscopic equations describing sound propagation through the material. This allowed us to conclude that the macroscopic mass balance is significantly modified by sorption, inter-scale (micro- to/from nanopore scales) mass diffusion, and inter-scale (pore to/from micro- and nanopore scales) pressure diffusion. This modification is accounted for by the dynamic compressibility of the effective saturating fluid that presents atypical properties that lead to slower speed of sound and higher sound attenuation, particularly at low frequencies. In contrast, it is shown that the physical processes occurring at the micro-nano-scale do not affect the macroscopic fluid flow through the material. The developed theory is exemplified by introducing an analytical model for multiscale sorptive granular materials, which is experimentally validated by comparing its predictions with acoustic measurements on granular activated carbons. Furthermore, we provide empirical evidence supporting an alternative method for measuring sorption and mass diffusion properties of multiscale sorptive materials using sound waves.
Enantioselective extraction of (+)-(S)-citalopram and its main metabolites using a tailor-made stir bar chiral imprinted polymer for their LC-ESI-MS/MS quantitation in urine samples.
Unceta, Nora; Gómez-Caballero, Alberto; García, Deiene; Díaz, Goretti; Guerreiro, Antonio; Piletsky, Sergey; Goicolea, M Aránzazu; Barrio, Ramón J
This paper reports the application of a chiral imprinted polymer (CIP)-coated stir bar for the selective extraction of (+)-(S)-citalopram (SCIT) and its main metabolites, (+)-(S)-desmethylcitalopram (SDCIT) and (+)-(S)-didesmethylcitalopram (SDDCIT), from urine samples. The developed device has been demonstrated to be capable of selectively extracting the three target analytes from urine samples without saturating the imprinted sites. A CIP-coated stir bar sorptive extraction procedure (CIP-SBSE) is proposed for the isolation of SCIT, SDCIT and SDDCIT followed by their subsequent analysis using liquid chromatography ion trap mass spectrometry (LC-ITMS). Deuterated SCIT-d6 was used as an internal standard. The method was validated using a standard procedure, which revealed that a quantification of 5 ng mL(-1) was obtained in urine samples and that the accuracy and precision were within the established values while no matrix effect was observed. Copyright © 2013 Elsevier B.V. All rights reserved.
Sorptive capacities of lipids determined by passive dosing of non-polar organic chemicals
DEFF Research Database (Denmark)
Jahnke, Annika; Kierkegaard, Amelie; Bolinius, Damien
VMS), chlorobenzenes and polychlorinated biphenyls via a common headspace over an olive oil donor phase to transfer the same chemical activity into the samples; iii) sampling of EOM and olive oil controls at different time points; iv) purge-and-trap extraction of the model chemicals onto ENV+ SPE cartridges, elution...... and GC/MS analysis; v) characterization of the lipid composition in all samples via NMR. Our experiments demonstrate that the sorptive capacities of the EOM samples do not differ significantly from the olive oil controls if the EOM consists of neutral lipids only. However, the EOM samples show small...
While heuristic optimization is applied in environmental applications, ad-hoc algorithm configuration is typical. We use a multi-layer sorptive barrier design problem as a benchmark for an algorithm-tuning procedure, as applied to three heuristics (genetic algorithms, simulated ...
Solar sorptive cooling. Technologies, user requirements, practical experience, future prospects
Energy Technology Data Exchange (ETDEWEB)
Treffinger, P. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Hardthausen (Germany); Hertlein, H.P. [eds.] [Forschungsverbund Sonnenenergie, Koeln (Germany)
Sorptive cooling techniques permit the use of low-temperature solar heat, i.e. a renewable energy of low cost and world-wide availability. The Forschungsverbund Sonnenenergie intends to develop solar sorptive cooling technologies to the prototype stage and, in cooperation with the solar industry and its end users, to promote practical application in air conditioning of buildings and cold storage of food. The workshop presents an outline of the state of development of solar sorptive cooling from the view of users and developers. Exemplary solar cooling systems are described, and the potential of open and closed sorptive processes is assessed. Future central activities will be defined in an intensive discussion between planners, producers, users and developers. [German] Der Einsatz von Sorptionstechniken zur Kaelteerzeugung erlaubt es, als treibende Solarenergie Niedertemperatur-Solarwaerme einzusetzen, also eine regenerative Energie mit sehr geringen Kosten und weltweiter Verfuegbarkeit. Der Forschungsverbund Sonnenenergie hat sich als Aufgabe gestellt, die Techniken der solaren Sorptionskuehlung bis zum Prototyp zu entwickeln und mit Industrie und Nutzern die praktische Anwendung voranzubringen. Die Anwendungsfelder sind die Klimatisierung von Gebaeuden und die Kaltlagerung von Lebensmitteln. Der Workshop gibt einen Ueberblick zum Entwicklungsstand der solaren Sorptionskuehlung aus der Sicht der Anwender und Entwickler. Bereits ausgefuehrte Beispiele zur solaren Kuehlung werden vorgestellt und das Potential geschlossener und offener Sorptionsverfahren angegeben. In intensiver Diskussion zwischen Planern, Herstellern, Nutzern und Entwicklern sollen kuenftige Arbeitsschwerpunkte herausgearbeitet werden. (orig.)
Multilayer SnSb4-SbSe Thin Films for Phase Change Materials Possessing Ultrafast Phase Change Speed and Enhanced Stability.
Liu, Ruirui; Zhou, Xiao; Zhai, Jiwei; Song, Jun; Wu, Pengzhi; Lai, Tianshu; Song, Sannian; Song, Zhitang
A multilayer thin film, comprising two different phase change material (PCM) components alternatively deposited, provides an effective means to tune and leverage good properties of its components, promising a new route toward high-performance PCMs. The present study systematically investigated the SnSb 4 -SbSe multilayer thin film as a potential PCM, combining experiments and first-principles calculations, and demonstrated that these multilayer thin films exhibit good electrical resistivity, robust thermal stability, and superior phase change speed. In particular, the potential operating temperature for 10 years is shown to be 122.0 °C and the phase change speed reaches 5 ns in the device test. The good thermal stability of the multilayer thin film is shown to come from the formation of the Sb 2 Se 3 phase, whereas the fast phase change speed can be attributed to the formation of vacancies and a SbSe metastable phase. It is also demonstrated that the SbSe metastable phase contributes to further enhancing the electrical resistivity of the crystalline state and the thermal stability of the amorphous state, being vital to determining the properties of the multilayer SnSb 4 -SbSe thin film.
Mechano-sorptive creep of Portuguese pinewood chemically modified
Directory of Open Access Journals (Sweden)
Barroso Lopes Duarte
Full Text Available The effect of chemical modification on mechano-sorptive creep in bending was studied by experimental work. Stakes with 20 × 20 × 400 mm RTL of Portuguese wood species (Pinus pinaster Aiton modified with 1,3-dimethylol-4,5- dihydroxyethyleneurea (DMDHEU, m-methylated melamine resin (MMF, tetraethoxysilane (TEOS and amid wax (WA were measured under asymmetric moistening conditions over a period of 42 days (app. 1000 hours with stress level (SL of 12 MPa, according to ENV 1156.
Sorptive thin film microextraction followed by direct solid state spectrofluorimetry: A simple, rapid and sensitive method for determination of carvedilol in human plasma.
Karimi, Shima; Talebpour, Zahra; Adib, Noushin
A poly acrylate-ethylene glycol (PA-EG) thin film is introduced for the first time as a novel polar sorbent for sorptive extraction method coupled directly to solid-state spectrofluorimetry without the necessity of a desorption step. The structure, polarity, fluorescence property and extraction performance of the developed thin film were investigated systematically. Carvedilol was used as the model analyte to evaluate the proposed method. The entire procedure involved one-step extraction of carvedilol from plasma using PA-EG thin film sorptive phase without protein precipitation. Extraction variables were studied in order to establish the best experimental conditions. Optimum extraction conditions were the followings: stirring speed of 1000 rpm, pH of 6.8, extraction temperature of 60 °C, and extraction time of 60 min. Under optimal conditions, extraction of carvedilol was carried out in spiked human plasma; and the linear range of calibration curve was 15-300 ng mL(-1) with regression coefficient of 0.998. Limit of detection (LOD) for the method was 4.5 ng mL(-1). The intra- and inter-day accuracy and precision of the proposed method were evaluated in plasma sample spiked with three concentration levels of carvedilol; yielding a recovery of 91-112% and relative standard deviation of less than 8%, respectively. The established procedure was successfully applied for quantification of carvedilol in plasma sample of a volunteer patient. The developed PA-EG thin film sorptive phase followed by solid-state spectrofluorimetric method provides a simple, rapid and sensitive approach for the analysis of carvedilol in human plasma. Copyright © 2016 Elsevier B.V. All rights reserved.
Sorptive removal of tetracycline from water by palygorskite
International Nuclear Information System (INIS)
Chang, Po-Hsiang; Li, Zhaohui; Yu, Tsai-Luen; Munkhbayer, Sandagdori; Kuo, Tzu-Hsing; Hung, Yu-Chiao; Jean, Jiin-Shuh; Lin, Kao-Hung
Extensive use of pharmaceuticals and growth hormone in farm animal and live stocks has resulted in their frequent detection in soils, groundwater, and wastewater. The fate and transport of these compounds are strongly affected by their sorptive behavior to the soil minerals and humic materials. In this research, we conducted the sorption of tetracycline (TC), a common antibiotic, on palygorskite (PFL-1), a fibrous clay mineral of high surface area and high sorptivity towards organic compounds. The results showed that the sorption capacity of TC on PFL-1 was as high as 210 mmol/kg at pH 8.7. The sorption was relatively fast and reached equilibrium in 2 h. Solution pH and ionic strength had significant effects on TC sorption. The sorption of TC by palygorskite is endothermic and the free energy of sorption is in the range of -10 to -30 kJ/mol, suggesting a strong physical sorption. The X-ray diffraction patterns before and after TC sorption revealed no changes in d-spacing and intensity under different pH and initial TC concentrations, indicating that the sorbed TC molecules are on the external surface of the mineral in contrast to intercalation of TC into swelling clays, such as montmorillonite. The small positive value of entropy change suggested that TC molecules are in disordered arrangement on palygorskite surfaces. Surface sorption of TC on PFL-1 is further supported by the derivative of gravimetric analysis and by the calculation of the amount of TC sorption normalized to the surface area. The results suggest that palygorskite could be a good candidate to remove TC from wastewater containing higher amounts of TC.
Optimum Installation of Sorptive Building Materials Using Contribution Ratio of Pollution Source for Improvement of Indoor Air Quality.
Park, Seonghyun; Seo, Janghoo
Reinforcing the insulation and airtightness of buildings and the use of building materials containing new chemical substances have caused indoor air quality problems. Use of sorptive building materials along with removal of pollutants, constant ventilation, bake-out, etc. are gaining attention in Korea and Japan as methods for improving such indoor air quality problems. On the other hand, sorptive building materials are considered a passive method of reducing the concentration of pollutants, and their application should be reviewed in the early stages. Thus, in this research, activated carbon was prepared as a sorptive building material. Then, computational fluid dynamics (CFD) was conducted, and a method for optimal installation of sorptive building materials was derived according to the indoor environment using the contribution ratio of pollution source (CRP) index. The results show that a method for optimal installation of sorptive building materials can be derived by predicting the contribution ratio of pollutant sources according to the CRP index.
Comparative study of cerium (IV) sorptive properties in zeolite Y and clinoptilolite
International Nuclear Information System (INIS)
Garcia D, O.C.
Among the problems of protecting the environment from radioactive contamination, the reduction of radioactive releases by improving monitoring, decontamination, and burial methods is one of the most important. Natural sorbents are gaining increased significance for solving this problem. Among these, zeolites deserve special attention since they have sufficient sorptive capacity, are highly radiation resistant, are widely distributed exhibit selectivity and are inexpensive. In the present work we determine experimentally the sorptive characteristics of clinoptilolite as a function of various factors and demonstrate that clinoptilolite is capable of sorbing Ce(IV) over a wide pH range. (Author)
Estimation of hydraulic conductivities of Yucca Mountain tuffs from sorptivity and water retention measurements
International Nuclear Information System (INIS)
Zimmerman, R.W.; Bodvarsson, G.S.
The hydraulic conductivity functions of the matrix rocks at Yucca Mountain, Nevada, are among the most important data needed as input for the site-scale hydrological model of the unsaturated zone. The difficult and time-consuming nature of hydraulic conductivity measurements renders it infeasible to directly measure this property on large numbers of cores. Water retention and sorptivity measurements, however, can be made relatively rapidly. The sorptivity is, in principle, a unique functional of the conductivity and water retention functions. It therefore should be possible to invert sorptivity and water retention measurements in order to estimate the conductivity; the porosity is the only other parameter that is required for this inversion. In this report two methods of carrying out this inversion are presented, and are tested against a limited data set that has been collected by Flint et al. at the USGS on a set of Yucca Mountain tuffs. The absolute permeability is usually predicted by both methods to within an average error of about 0.5 - 1.0 orders of magnitude. The discrepancy appears to be due to the fact that the water retention curves have only been measured during drainage, whereas the imbibition water retention curve is the one that is relevant to sorptivity measurements. Although the inversion methods also yield predictions of the relative permeability function, there are yet no unsaturated hydraulic conductivity data against which to test these predictions
Permeable sorptive walls for treatment of hydrophobic organic contaminant plumes in groundwater
International Nuclear Information System (INIS)
Grathwohl, P.; Peschik, G.
Highly hydrophobic contaminants are easily adsorbed from aqueous solutions. Since for many of these compounds sorption increases with increasing organic carbon content natural materials such as bituminous shales and coals may be used in permeable sorptive walls. This, however, only applies if sorption is at equilibrium, which may not always be the case in groundwater treatment using a funnel-and-gate system. In contrast to the natural solids, granular activated carbons (GACs) have very high sorption capacities and reasonably fast sorption kinetics. The laboratory results show that application of GACs (e.g. F100) is economically feasible for in situ removal of polycyclic aromatic hydrocarbons (PAH) from groundwater at a former manufactured gas plant site (MGP). For less sorbing compounds (such as benzene, toluene, xylenes) a combination of adsorption and biodegradation is necessary (i.e. sorptive + reactive treatment)
Weathering products of basic rocks as sorptive materials of natural radionuclides
International Nuclear Information System (INIS)
Omelianenko, B.I.; Niconov, B.S.; Ryzhov, B.I.; Shikina, N.D.
The principal requirements for employing natural minerals as buffer and backfill material in high-level waste (HLW) repositories are high sorptive properties, low water permeability, relatively high thermal conductivity, and thermostability. The major task of the buffer is to prevent the penetration of radionuclides into groundwater. The authors of this report examined weathered basic rocks from three regions of Russia in consideration as a suitable radioactive waste barrier
Effect of chemical modification on reduction and sorptive properties of chars from hydropyrolysis of coal
Energy Technology Data Exchange (ETDEWEB)
Stanczyk, K.; Miga, K.; Fabis, G.; Jastrzab, K. [Polskiej Akademii Nauk, Gliwice (Poland)
Hydropyrolysis of bituminous coal and lignite as way of synthesis of adsorbents has been applied. Chemical modification of chars based on simultaneous carbonization of coal and plastics containing sulfur and nitrogen has been carried out. It was stated that modified chars exhibit better reduction and sorptive properties than non-modified and that modified adsorbents made of lignite exceed commercial ones. 7 refs., 4 figs., 3 tabs.
Sorptive stabilization of organic matter by amorphous Al hydroxide
Schneider, M.P.W.; Scheel, T.; Mikutta, R.; van Hees, P.; Kaiser, K.; Kalbitz, K.
Amorphous Al hydroxides (am-Al(OH)(3)) strongly sorb and by this means likely protect dissolved organic matter (OM) against microbial decay in soils. We carried out batch sorption experiments (pH 4.5; 40 mg organic C L-1) with OM extracted from organic horizons under a Norway spruce and a European
DEFF Research Database (Denmark)
Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra
The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/......., organism, tissue and disease terms. The evaluators in the BioCreative V Interactive Annotation Task found the system to be intuitive, useful, well documented and sufficiently accurate to be helpful in spotting relevant text passages and extracting organism and environment terms. Comparison of fully manual...
Equilibrium sorptive enrichment on poly(dimethylsiloxane) particles for trace analysis of volatile compounds in gaseous samples
Baltussen, H.A.; David, F.; Sandra, P.J.F.; Janssen, J.G.M.; Cramers, C.A.M.G.
A novel approach for sample enrichment, namely, equilibrium sorptive enrichment (ESE), is presented. A packed bed of sorption (or partitioning) material is used to enrich volatiles from gaseous samples. Normally, air sampling is stopped before breakthrough occurs, but this approach is not very
Analysis of mechano-sorptive effect in oscillatory drying of beech timber
Directory of Open Access Journals (Sweden)
Milić Goran
Full Text Available The paper shows results of analysis of influences of oscillating parameters of drying on measuring wood moisture content in the kiln, rate and quality of drying. For this analysis, we used a conventional drying cycle, a cycle with oscillating equilibrium moisture content (EMC, and a cycle with oscillating temperatures. A special software tool was created for managing the oscillations. It was shown that oscillations of EMC and temperatures result in cyclic changes in wood MC, but also in the additional inaccuracies of MC measurements in the kiln. The drying process of the cycle with oscillating EMC lasted somewhat shorter than the other two cycles. Drying quality was the same or better in the cycles with oscillations as compared to the conventionally dried cycle, and the smaller tensions in the wood confirmed the activation of the additional mechano-sorptive effect during cyclic changes of MC in surface layers. [Projekat Ministarstva nauke Republike Srbije, br. TR 31041 i br. TR 37008
Evaluation of sorptive flotation technique for enhanced removal of radioactive Eu(III) from aqueous solutions
Energy Technology Data Exchange (ETDEWEB)
Ezzat, Amir; Saad, Ebtissam A. [Ain Shams Univ., Cairo (Egypt). Chemistry Dept.; Mahmoud, Mamdoh R. [Atomic Energy Authority, Cairo (Egypt). Nuclear Chemistry Dept.; Soliman, Mohamed A. [Atomic Energy Authority, Cairo (Egypt). Egypt Second Research Reactor; Kandil, Abdelhakim [Helwan Univ., Cairo (Egypt). Chemistry Dept.
The present study aims at the removal of Eu(III) from aqueous solutions by sorptive flotation process. This process involves adsorption of Eu(III) onto bentonite and kaolinite clays followed by floatation using sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) collectors. The effect of adsorption parameters (pH, contact time, clay weight, Eu(III) concentration, ionic strength) as well as flotation parameters (collector and frother concentrations, bubbling time, concentrations of foreign cations and anions) on the removal efficiency of Eu(III) were studied. The obtained results show that Eu(III) ions are removed efficiently (R% ∝ 95%) at pH=4 after 1 h shaking with clay and 15 min floatation. The adsorption kinetics of Eu(III) onto the employed clays followed the pseudo-second-order model and the equilibrium data fitted well to the Freundlich isotherm model.
Sorptive and desorptive fractionation of dissolved organic matter by mineral soil matrices.
Oren, Adi; Chefetz, Benny
Interactions of dissolved organic matter (DOM) with soil minerals, such as metal oxides and clays, involve various sorption mechanisms and may lead to sorptive fractionation of certain organic moieties. While sorption of DOM to soil minerals typically involves a degree of irreversibility, it is unclear which structural components of DOM correspond to the irreversibly bound fraction and which factors may be considered determinants. To assist in elucidating that, the current study aimed at investigating fractionation of DOM during sorption and desorption processes in soil. Batch DOM sorption and desorption experiments were conducted with organic matter poor, alkaline soils. Fourier-transform infrared (FTIR) and UV-Vis spectroscopy were used to analyze bulk DOM, sorbed DOM, and desorbed DOM fractions. Sorptive fractionation resulted mainly from the preferential uptake of aromatic, carboxylic, and phenolic moieties of DOM. Soil metal-oxide content positively affected DOM sorption and binding of some specific carboxylate and phenolate functional groups. Desorptive fractionation of DOM was expressed by the irreversible-binding nature of some carboxylic moieties, whereas other bound carboxylic moieties were readily desorbed. Inner-sphere, as opposed to outer-sphere, ligand-exchange complexation mechanisms may be responsible for these irreversible, as opposed to reversible, interactions, respectively. The interaction of aliphatic DOM constituents with soil, presumably through weak van der Waals forces, was minor and increased with increasing proportion of clay minerals in the soil. Revealing the nature of DOM-fractionation processes is of great importance to understanding carbon stabilization mechanisms in soils, as well as the overall fate of contaminants that might be associated with DOM. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Early age compressive strength, porosity, and sorptivity of concrete using peat water to produce and cure concrete
Olivia, Monita; Ismeddiyanto, Wibisono, Gunawan; Sitompul, Iskandar R.
Construction in peatland has faced scarce water sources for mixing and curing concrete. It is known that peat water has high organic content and low pH that can be harmful to concrete in the environment. In some remote areas in Riau Province, contractors used peat water directly without sufficient treatments to comply with SKSNI requirements of concrete mixing water. This paper presents a study of compressive strength, porosity and sorptivity of Ordinary Portland Cement (OPC) and blended OPC-Palm Oil Fuel Ash (OPC-POFA) concrete. The specimens were mixed using natural water and peat water, then some of them were cured in fresh water and peat water. Six mixtures were investigated using a variation of cement, mixing water and curing water. Tap water is used as control mixing and curing water for all specimens. The compressive strength, porosity and sorptivity were calculated at seven and 28 days. Results indicate that the use of peat water will cause low compressive strength, high porosity and sorptivity for both OPC and OPC-POFA concrete. Using peat water and curing the specimens in tap water could improve the early strength, porosity and sorptivity of OPC concrete; however, it has an adverse effect on OPC-POFA specimens. The properties of early age concrete of both types (OPC and OPC-POFA) using peat water were as good as those with tap water. Therefore, it is suggested that peat water should be considered as mixing and curing water for concrete where tap water resources are scarce. Investigation of its long-term properties, as well as extending the observed age of concrete is recommended before any use of peat water.
Natural sorptive barriers in Yucca Mountain, Nevada, for long-term isolation of high-level waste
International Nuclear Information System (INIS)
Bish, D.L.; Vaniman, D.T.; Rundberg, R.S.; Wolfsberg, K.; Daniels, W.R.; Broxton, D.E.
There are several sorptive phases occurring naturally in the silicic tuffs at Yucca Mountain, Nevada, that can aid in the long-term isolation of high-level wastes. These phases include hydrated volcanic glasses, smectites and zeolites. Los Alamos has a continuing programme to investigate the mineralogy and stratigraphy of the tuffs at Yucca Mountain. In addition, extensive data have been obtained on the sorptive behaviour of technetium, strontium, caesium, barium, cerium, europium, uranium, neptunium, plutonium and americium on the minerals in tuffs. Sorption of elements by ion-exchange processes is high in tuffs containing smectite and the zeolites clinoptilolite-heulandite and mordenite. Moreover, sorption correlates with abundances of these minerals. Sorption is not as high for the zeolite analcime and for volcanic glass. Elements that may not sorb by ion exchange, e.g. plutonium, also tend to be sorbed when the zeolite abundance is high, but the correlations are less clearly defined. Because of the correlation between sorptive capacity and mineralogy, an accurate knowledge of mineral distribution and stratigraphy is essential. The distribution of hydrated glasses is stratigraphically controlled, and the glasses occur in narrow unaltered horizons as vitrophyres and as vitric tuff. Although glasses are of minor importance as sorptive phases, they are very reactive and can alter to other minerals if heated in the presence of water. Smectite clays are reversibly expandable and are widespread in tuffs, but their beneficial properties can be modified by prolonged exposure to elevated temperatures. The zeolites clinoptilolite-heulandite and mordenite occur in high concentrations in silicic tuffs, mostly as secondary alterations of non-welded and poorly welded tuffs; their distribution is therefore stratigraphically controlled
Role of biofilms in sorptive removal of steroidal hormones and 4-nonylphenol compounds from streams
Writer, Jeffrey H.; Ryan, Joseph N.; Barber, Larry B.
Stream biofilms play an important role in geochemical processing of organic matter and nutrients, however, the significance of this matrix in sorbing trace organic contaminants is less understood. This study focused on the role of stream biofilms in sorbing steroidal hormones and 4-nonylphenol compounds from surface waters using biofilms colonized in situ on artificial substrata and subsequently transferred to the laboratory for controlled batch sorption experiments. Steroidal hormones and 4-nonylphenol compounds readily sorb to stream biofilms as indicated by organic matter partition coefficients (Kom, L kg–1) for 17β-estradiol (102.5–2.8 L kg–1), 17α-ethynylestradiol (102.5–2.9 L kg–1), 4-nonylphenol (103.4–4.6 L kg–1), 4-nonylphenolmonoethoxylate (103.5–4.0 L kg–1), and 4-nonylphenoldiethoxylate (103.9–4.3 L kg–1). Experiments using water quality differences to induce changes in the relative composition of periphyton and heterotrophic bacteria in the stream biofilm did not significantly affect the sorptive properties of the stream biofilm, providing additional evidence that stream biofilms will sorb trace organic compounds under of variety of environmental conditions. Because sorption of the target compounds to stream biofilms was linearly correlated with organic matter content, hydrophobic partition into organic matter appears to be the dominant mechanism. An analysis of 17β-estradiol and 4-nonylphenol hydrophobic partition into water, biofilm, sediment, and dissolved organic matter matrices at mass/volume ratios typical of smaller rivers showed that the relative importance of the stream biofilm as a sorptive matrix was comparable to bed sediments. Therefore, stream biofilms play a primary role in attenuating these compounds in surface waters. Because the stream biofilm represents the base of the stream ecosystem, accumulation of steroidal hormones and 4-nonylphenol compounds in the stream biofilm may be an exposure pathway for
Removal of natural hormones in dairy farm wastewater using reactive and sorptive materials.
Cai, Kai; Phillips, Debra H; Elliott, Christopher T; Muller, Marc; Scippo, Marie-Louise; Connolly, Lisa
The objective of this study was to examine the oestrogen and androgen hormone removal efficiency of reactive (Connelly zero-valent iron (ZVI), Gotthart Maier ZVI) and sorptive (AquaSorb 101 granular activated carbon (GAC) and OrganoLoc PM-100 organoclay (OC)) materials from HPLC grade water and constructed wetland system (CWS) treated dairy farm wastewater. Batch test studies were performed and hormone concentration analysis carried out using highly sensitive reporter gene assays (RGAs). The results showed that hormonal interaction with these materials is selective for individual classes of hormones. Connelly ZVI and AquaSorb 101 GAC were more efficient in removing testosterone (Te) than 17β-estradiol (E2) and showed faster removal rates of oestrogen and androgen than the other materials. Gotthart Maier ZVI was more efficient in removing E2 than Te. OrganoLoc PM-100 OC achieved the lowest final concentration of E2 equivalent (EEQ) and provided maximum removal of both oestrogens and androgens. Copyright © 2013 Elsevier B.V. All rights reserved.
Sorptivity of rocks and soils of the van Genuchten-Mualem type
Energy Technology Data Exchange (ETDEWEB)
Zimmerman, R.W.; Bodvarsson, G.S. [Lawrence Berkeley Lab., CA (United States)
One hydrological process that will have great relevance to the performance of the proposed underground radioactive waste repository at Yucca Mountain, Nevada, is that of the absorption of water from a water-filled fracture into the adjacent unsaturated rock formation. The rate at which water is imbibed by a rock depends on the hydrological properties of the rock and on the initial saturation (or initial capillary suction) of the formation. The hydrological properties that affect imbibition are the relative permeability function and the capillary pressure function. These functions are often collectively referred to as the `characteristic functions` of the porous medium. For one-dimensional absorption, it can be shown that, regardless of the details of the characteristic functions, the total amount of water imbibed by the formation, per unit surface area, will be proportional to the square root of the elapsed time. Hence the ability of a rock or soil to imbibe water can be quantified by a parameter known as the sorptivity S, which is defined such that the cumulative volumetric liquid influx per unit area is given by Q = S{radical}t. The paper discusses the simplification of these characteristic functions of porous medium.
A permeability model for coal and other fractured, sorptive-elastic media
Energy Technology Data Exchange (ETDEWEB)
Robertson, E.P.; Christiansen, R.L. [Marathon Oil Co., Houston, TX (United States). Research & Development Facility
This paper describes the derivation of a new equation that can be used to model the permeability behavior of a fractured, sorptive-elastic medium, such as coal, under variable stress conditions. The equation is applicable to confinement pressure schemes commonly used during the collection of permeability data in the laboratory. The model is derived for cubic geometry under biaxial or hydrostatic confining pressures. The model is designed to handle changes in permeability caused by adsorption and desorption of gases onto and from the matrix blocks in fractured media. The model equations can be used to calculate permeability changes caused by the production of methane (CH{sub 4}) from coal as well as the injection of gases, such as carbon dioxide, for sequestration in coal. Sensitivity analysis of the model found that each of the input variables can have a significant impact on the outcome of the permeability forecast as a function of changing pore pressure, thus, accurate input data are essential. The permeability model also can be used as a tool to determine input parameters for field simulations by curve fitting laboratory-generated permeability data. The new model is compared to two other widely used coal-permeability models using a hypothetical coal with average properties.
Longitudinal Mechano-Sorptive Creep Behavior of Chinese Fir in Tension during Moisture Adsorption Processes.
Peng, Hui; Lu, Jianxiong; Jiang, Jiali; Cao, Jinzhen
To provide comprehensive data on creep behaviors at relative humidity (RH) isohume conditions and find the basic characteristics of mechano-sorptive (MS) creep (MSC), the tensile creep behaviors, "viscoelastic creep (VEC)" at equilibrium moisture content and MSC during adsorption process, were performed on Chinese fir in the longitudinal direction under 20%, 40%, 60% and 80% RH (25 °C) and at 1, 1.3, and 1.6 MPa, respectively. The free swelling behavior was also measured, where the climate conditions corresponded with MSC tests. Based on the databases of free swelling, VEC, and MSC, the existence of MS effect was examined, and the application of the rheological model under the assumption of partitioned strain was investigated. The results revealed that both VEC and MSC increased with magnitude of applied stress, and the increasing RH level. Under all RH isohume conditions, the total strain of MSC was greater than that of VEC. The influence of RH level on VEC was attributed to the water plasticization effect, whereas that on MSC was presumed to be the effect of water plasticization and unstable state in the wood cell wall. In addition, the RH level promoted the relaxation behavior in MSC, while it slightly affected the relaxation behavior in VEC. In the future, the rheological model could consider the link between load configuration and the anatomic structural feature of wood.
Biochar characteristics produced from food-processing products and their sorptive capacity for mercury and phenanthrene
Fotopoulou, Kalliopi N.; Karapanagioti, Hrissi K.; Manariotis, Ioannis D.
Various organic-rich wastes including wood chips, animal manure, and crop residues have been used for biochar production. Biochar is used as an additive to soils to sequester carbon and improve soil fertility but its use as a sorbent for environmental remediation processes is gaining increased attention. Surface properties such as point of zero charge, surface area and pore volume, surface topography, surface functional groups and acid-base behavior are important factors, which affect sorption efficiency. Understanding the surface alteration of biochars increases our understanding of the pollutant-sorbent interaction. The scope of the present work was to evaluate the effect of key characteristics of biochars on their sorptive properties. Raw materials for biochar production were evaluated including byproducts from brewering, coffee, wine, and olive oil industry. The charring process was performed at different temperatures under limited-oxygen conditions using specialized containers. The surface area, the pore volume, and the average pore size of the biochars were determined. Open surface area and micropore volume were determined using t-plot method and Harkins & Jura equation. Raw food-processing waste demonstrates low surface area that increases by 1 order of magnitude by thermal treatment up to 750oC. At temperatures from 750 up to 900oC, pyrolysis results to biochars with surface areas 210-700 m2/g. For the same temperature range, a high percentage (46 to73%) of the pore volume of the biochars is due to micropores. Positive results were obtained when high surface area biochars were tested for their ability to remove organic (i.e. phenanthrene) and inorganic (i.e. mercury) compounds from aqueous solutions. All these properties point to new materials that can effectively be used for environmental remediation.
Comparative study of cerium (IV) sorptive properties in zeolite Y and clinoptilolite; Estudio comparativo de la fijacion de cerio (IV) en zeolitas, faujasita-Y y clinoptilolita
Energy Technology Data Exchange (ETDEWEB)
Garcia D, O C
Among the problems of protecting the environment from radioactive contamination, the reduction of radioactive releases by improving monitoring, decontamination, and burial methods is one of the most important. Natural sorbents are gaining increased significance for solving this problem. Among these, zeolites deserve special attention since they have sufficient sorptive capacity, are highly radiation resistant, are widely distributed exhibit selectivity and are inexpensive. In the present work we determine experimentally the sorptive characteristics of clinoptilolite as a function of various factors and demonstrate that clinoptilolite is capable of sorbing Ce(IV) over a wide pH range. (Author).
Sorptive Uptake Studies of an Aryl-Arsenical with Iron Oxide Composites on an Activated Carbon Support
Directory of Open Access Journals (Sweden)
Jae H. Kwon
Full Text Available Sorption uptake kinetics and equilibrium studies for 4-hydroxy-3-nitrobenzene arsonic acid (roxarsone was evaluated with synthetic magnetite (Mag-P, commercial magnetite (Mag-C, magnetite 10%, 19%, and 32% composite material (CM-10, -19, -32 that contains granular activated carbon (GAC, and synthetic goethite at pH 7.00 in water at 21 °C for 24 h. GAC showed the highest sorptive removal of roxarsone and the relative uptake for each sorbent material with roxarsone are listed in descending order as follows: GAC (471 mg/g > goethite (418 mg/g > CM-10 (377 mg/g CM-19 (254 mg/g > CM-32 (227 mg/g > Mag-P (132 mg/g > Mag-C (29.5 mg/g. The As (V moiety of roxarsone is adsorbed onto the surface of the iron oxide/oxyhydrate and is inferred as inner-sphere surface complexes; monodentate-mononuclear, bidentate-mononuclear, and bidentate-binuclear depending on the protolytic speciation of roxarsone. The phenyl ring of roxarsone provides the primary driving force for the sorptive interaction with the graphene surface of GAC and its composites. Thus, magnetite composites are proposed as multi-purpose adsorbents for the co-removal of inorganic and organic arsenicals due to the presence of graphenic and iron oxide active adsorption sites.
An Approach for Measuring the Sorptive Behavior of Odorants Using a Multifunction Thermal Desorber Unit: Preliminary Tests on Reduced Sulfur Compounds
Directory of Open Access Journals (Sweden)
Sang-Woo Joo
Full Text Available In this study, the sorptive behavior of reduced sulfur compounds (RSC was investigated using a combination of thermal desorber (TD unit and gas chromatography (GC. To examine the sorptive properties of RSC on textile materials, two types of experiments were conducted under experimental conditions favorable for sorptive processes. In all the experiments, gaseous standards of hydrogen sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide were supplied to initiate the adsorption processes on textile pieces. The textile pieces were then forced to release those adsorbed RSC under a fixed condition. It was found that the extent of adsorption, if evaluated quantitatively, occurred at approximately 1/1000 to 1/100 of the level of RSC standards supplied originally to induce adsorption. It also indicated that RSC adsorption was affected very sensitively by the initial exposure durations to induce RSC adsorption with an exponential decrease in relative recovery (RR values with increasing exposure time. The relative sorptive patterns, when compared between different RSCs, were affected most sensitively by such factors as molecular weight and/or physical contact conditions.
Preparation and application of novel selective and polar materials for sorptive extraction of emerging contaminants from environmental waters
Gilart Alzuria, Núria
La present Tesi Doctoral té com a objectiu principal el desenvolupament de nous materials per a diferents tècniques d'extracció per sorció, com són l'extracció en fase sòlida i l'extracció mitjançant barres magnètiques agitadores. Ambdues tècniques van ser aplicades a la cromatografia de líquids seguida de l'espectroscòpia de masses en tàndem (LC-MS/MS) per a la determinació de diversos contaminants orgànics considerats com emergents, com són fàrmacs, drogues d'abús i productes d'higiene pers...
Determination of total Sb,Se Te, and Bi and evaluation of their inorganic species in garlic by hydride-generation-atomic-fluorescence spectrometry
Energy Technology Data Exchange (ETDEWEB)
Matos Reyes, M.N.; Cervera, M.L.; Guardia, M. de la [University of Valencia, Department of Analytical Chemistry, Burjassot, Valencia (Spain)
A sensitive and simple analytical method has been developed for determination of Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), Te(VI), and Bi(III) in garlic samples by using hydride-generation-atomic-fluorescence spectrometry (HG-AFS). The method is based on a single extraction of the inorganic species by sonication at room temperature with 1 mol L{sup -1} H{sub 2}SO{sub 4} and washing of the solid phase with 0.1% (w/v) EDTA, followed by measurement of the corresponding hydrides generated under two different experimental conditions directly and after a pre-reduction step. The limit of detection of the method was 0.7 ng g{sup -1} for Sb(III), 1.0 ng g{sup -1} for Sb(V), 1.3 ng g{sup -1} for Se(IV), 1.0 ng g{sup -1} for Se(VI), 1.1 ng g{sup -1} for Te(IV), 0.5 ng g{sup -1} for Te(VI), and 0.9 ng g{sup -1} for Bi(III), in all cases expressed in terms of sample dry weight. (orig.)
Calibration and field performance of membrane-enclosed sorptive coating for integrative passive sampling of persistent organic pollutants in water
International Nuclear Information System (INIS)
Vrana, Branislav; Paschke, Albrecht; Popp, Peter
Membrane-enclosed sorptive coating (MESCO) is a miniaturised monitoring device that enables integrative passive sampling of persistent, hydrophobic organic pollutants in water. The system combines the passive sampling with solventless preconcentration of organic pollutants from water and subsequent desorption of analytes on-line into a chromatographic system. Exchange kinetics of chemicals between water and MESCO was studied at different flow rates of water, in order to characterize the effect of variable environmental conditions on the sampler performance, and to identify a method for in situ correction of the laboratory-derived calibration data. It was found that the desorption of chemicals from MESCO into water is isotropic to the absorption of the analytes onto the sampler under the same exposure conditions. This allows for the in situ calibration of the uptake of pollutants using elimination kinetics of performance reference compounds and more accurate estimates of target analyte concentrations. A field study was conducted to test the sampler performance alongside spot sampling. A good agreement of contaminant patterns and water concentrations was obtained by the two sampling techniques. - A robust calibration method of a passive sampling device for monitoring of persistent organic pollutants in water is described
Heavy metal removal mechanisms of sorptive filter materials for road runoff treatment and remobilization under de-icing salt applications.
Huber, Maximilian; Hilbig, Harald; Badenberg, Sophia C; Fassnacht, Julius; Drewes, Jörg E; Helmreich, Brigitte
The objective of this research study was to elucidate the removal and remobilization behaviors of five heavy metals (i.e., Cd, Cu, Ni, Pb, and Zn) that had been fixed onto sorptive filter materials used in decentralized stormwater treatment systems receiving traffic area runoff. Six filter materials (i.e., granular activated carbon, a mixture of granular activated alumina and porous concrete, granular activated lignite, half-burnt dolomite, and two granular ferric hydroxides) were evaluated in column experiments. First, a simultaneous preloading with the heavy metals was performed for each filter material. Subsequently, the remobilization effect was tested by three de-icing salt experiments in duplicate using pure NaCl, a mixture of NaCl and CaCl2, and a mixture of NaCl and MgCl2. Three layers of each column were separated to specify the attenuation of heavy metals as a function of depth. Cu and Pb were retained best by most of the selected filter materials, and Cu was often released the least of all metals by the three de-icing salts. The mixture of NaCl and CaCl2 resulted in a stronger effect upon remobilization than the other two de-icing salts. For the material with the highest retention, the effect of the preloading level upon remobilization was measured. The removal mechanisms of all filter materials were determined by advanced laboratory methods. For example, the different intrusions of heavy metals into the particles were determined. Findings of this study can result in improved filter materials used in decentralized stormwater treatment systems. Copyright © 2016 Elsevier Ltd. All rights reserved.
Sorptive Removal of Cesium and Cobalt Ions in a Fixed bed Column Using Lewatit S100 Cation Exchange Resin
International Nuclear Information System (INIS)
El-Naggar, M.R.; Ibrahim, H.A.; El-Kamash, A.M.
The sorptive removal of cesium and cobalt ions from aqueous solutions in a fixed bed column packed with Lewatit S100® cation exchange resin has been investigated. A preliminary batch studies were performed to estimate the effect of pH and contact time on the sorption process. Results indicated that Cs + and Co 2+ could be efficiently removed using Lewatit S100® at a ph range of 4-7 with more affinity towards Cs than Co 2+ . Kinetic models have been applied to the sorption rate data and the relevant parameters were determined. The obtained results indicated that the sorption of both Cs + and Co 2+ on Lewatit S100 followed pseudo second-order rather than pseudo first-order or Morris-Webber model. Fixed bed experiments were conducted at a constant initial concentration of 100 mg/l whereas the effect of bed depth (3, 4.5 and 6 cm) and volumetric flow rate (3 and 5 ml/min.) on the breakthrough characteristics of the fixed bed sorption systems were determined. The experimental sorption data were fitted to the well-established column models namely; Thomas and BDST models to compute the different model parameters. The higher column sorption capacities were obtained at bed depth of 3 cm with a flow rate of 3 ml/min., for both Cs + and Co 2+ . The BDST model appeared to describe experimental results better than Thomas model. Results indicate that Lewatit S100® is an efficient material for the removal of cesium and cobalt ions from aqueous solutions.
Estimate of the soil water retention curve from the sorptivity and β parameter calculated from an upward infiltration experiment
Moret-Fernández, D.; Latorre, B.
The water retention curve (θ(h)), which defines the relationship between the volumetric water content (θ) and the matric potential (h), is of paramount importance to characterize the hydraulic behaviour of soils. Because current methods to estimate θ(h) are, in general, tedious and time consuming, alternative procedures to determine θ(h) are needed. Using an upward infiltration curve, the main objective of this work is to present a method to determine the parameters of the van Genuchten (1980) water retention curve (α and n) from the sorptivity (S) and the β parameter defined in the 1D infiltration equation proposed by Haverkamp et al. (1994). The first specific objective is to present an equation, based on the Haverkamp et al. (1994) analysis, which allows describing an upward infiltration process. Secondary, assuming a known saturated hydraulic conductivity, Ks, calculated on a finite soil column by the Darcy's law, a numerical procedure to calculate S and β by the inverse analysis of an exfiltration curve is presented. Finally, the α and n values are numerically calculated from Ks, S and β. To accomplish the first specific objective, cumulative upward infiltration curves simulated with HYDRUS-1D for sand, loam, silt and clay soils were compared to those calculated with the proposed equation, after applying the corresponding β and S calculated from the theoretical Ks, α and n. The same curves were used to: (i) study the influence of the exfiltration time on S and β estimations, (ii) evaluate the limits of the inverse analysis, and (iii) validate the feasibility of the method to estimate α and n. Next, the θ(h) parameters estimated with the numerical method on experimental soils were compared to those obtained with pressure cells. The results showed that the upward infiltration curve could be correctly described by the modified Haverkamp et al. (1994) equation. While S was only affected by early-time exfiltration data, the β parameter had a
Polytetrafluoroethylene-jacketed stirrer modified with graphene oxide and polydopamine for the efficient extraction of polycyclic aromatic hydrocarbons.
Zhang, Zinxin; Mwadini, Mwadini Ahmada; Chen, Zilin
Steel stirrers jacketed with polytetrafluoroethylene can be regarded as an ideal substrate for stirrer bar sorptive extraction. However, it is still a great challenge to immobilize graphene onto a polytetrafluoroethylene stirrer due to the high chemical resistance of the surface of a polytetrafluoroethylene stirrer. We describe here a method to modify the surface of polytetrafluoroethylene stirrers with graphene. In this work, graphene was used as the sorbent due to its excellent adsorption capability for aromatic compounds, such as polycyclic aromatic compounds. Graphene was successfully immobilized onto polytetrafluoroethylene-stirrer by a bio-inspired polydopamine functionalization method. The graphene-modified polytetrafluoroethylene-stirrer shows good stability and tolerance to stirring, ultrasonication, strong acidic and basic solutions, and to organic solvents. The multilayer coating was characterized by scanning electronic microscopy and Fourier transform infrared spectroscopy. After the optimization of some experimental conditions, the graphene-modified polytetrafluoroethylene stirrer was used for the stirrer bar sorptive extraction of polycyclic aromatic hydrocarbons, in which the binding between the polycyclic aromatic hydrocarbons and the graphene layer was mainly based on π-π stacking and hydrophobic interactions. The graphene-modified polytetrafluoroethylene-stirrer-based stirrer bar sorptive extraction and high-performance liquid chromatography method was developed for the determination of polycyclic aromatic hydrocarbons with great extraction efficiency, with enrichment factors from 18 to 62. The method has low limits of detection of 1-5 pg/mL, wide linear range (5-100 and 10-200 pg/mL), good linearity (R ≥ 0.9957) and good reproducibility (RSD ≤ 6.45%). The proposed method has been applied to determine polycyclic aromatic hydrocarbons in real dust samples. Good recoveries were obtained, ranging from 88.53 to 109.43%. © 2016 WILEY-VCH Verlag
Removal of copper(II) from some environmental samples by sorptive-flotation using powdered marble wastes as sorbents and oleic acid as surfactant.
Ghazy, S E; Samra, S E; Mahdy, A F M; El-Morsy, S M
A simple and economic experimental sorptive -flotation procedure is presented for the removal of copper(II) species from aqueous solutions. It is based on using powdered marble wastes (PMW), which are widespread and inexpensive and may represent an environmental problem, as the effective inorganic sorbent and oleic (HOL) as the surfactant. The main parameters (i.e. initial solution pH, sorbent, surfactant and copper concentrations, stirring times, ionic strength, temperature and the presence of foreign ions) influencing the flotation of PMW and /or Cu(II) were examined. Nearly, 100% of PMW and Cu(II) were removed from aqueous solutions at pH7 after stirring for 10 min and at room temperature, (approximately 25 degrees C). The procedure was successfully applied to recover Cu(II) spiked to some natural water samples. A mechanism for sorption and flotation is suggested.
Barbell-shaped stir bar sorptive extraction using dummy template molecularly imprinted polymer coatings for analysis of bisphenol A in water.
Liu, Ruimei; Feng, Feng; Chen, Guolin; Liu, Zhimin; Xu, Zhigang
This study reports the development of a novel dummy template molecularly imprinted polymer (MIP)-coated barbell-shaped stir bar. The MIP stir bar coatings were prepared by using 2,2-bis(4-hydroxyphenyl)butane (BPB), 4,4'-dihydroxydiphenylmethane (BPF), 4-tert-butylphenol (PTBP), and tetrabromobisphenol A (TBBA) as dummy templates using a capillary in situ polymerization method. Uniform coatings can be prepared controllably. The method is simple, easy, and reproducible. The barbell-shaped stir bar was developed by using medical silicone tubes as wheels. The wheels could be removed and reinstalled when necessary; therefore, the barbell-shaped stir bar was easy to disassemble and reassemble. The novel MIP-coated stir bar showed good selectivity for the target analyte, bisphenol A (BPA). The established method is selective and sensitive with a lower detection limit for BPA of 0.003 μg/L. The dummy template MIP-coated stir bar is suitable for trace BPA analysis in real environmental water samples without template leakage. The novel stir bar can be used at least 100 times.
Introducing a new and rapid microextraction approach based on magnetic ionic liquids: Stir bar dispersive liquid microextraction
International Nuclear Information System (INIS)
Chisvert, Alberto; Benedé, Juan L.; Anderson, Jared L.; Pierson, Stephen A.; Salvador, Amparo
With the aim of contributing to the development and improvement of microextraction techniques, a novel approach combining the principles and advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) is presented. This new approach, termed stir bar dispersive liquid microextraction (SBDLME), involves the addition of a magnetic ionic liquid (MIL) and a neodymium-core magnetic stir bar into the sample allowing the MIL coat the stir bar due to physical forces (i.e., magnetism). As long as the stirring rate is maintained at low speed, the MIL resists rotational (centrifugal) forces and remains on the stir bar surface in a manner closely resembling SBSE. By increasing the stirring rate, the rotational forces surpass the magnetic field and the MIL disperses into the sample solution in a similar manner to DLLME. After extraction, the stirring is stopped and the MIL returns to the stir bar without the requirement of an additional external magnetic field. The MIL-coated stir bar containing the preconcentrated analytes is thermally desorbed directly into a gas chromatographic system coupled to a mass spectrometric detector (TD-GC-MS). This novel approach opens new insights into the microextraction field, by using the benefits provided by SBSE and DLLME simultaneously, such as automated thermal desorption and high surface contact area, respectively, but most importantly, it enables the use of tailor-made solvents (i.e., MILs). To prove its utility, SBDLME has been used in the extraction of lipophilic organic UV filters from environmental water samples as model analytical application with excellent analytical features in terms of linearity, enrichment factors (67–791), limits of detection (low ng L −1 ), intra- and inter-day repeatability (RSD<15%) and relative recoveries (87–113%, 91–117% and 89–115% for river, sea and swimming pool water samples, respectively). - Highlights: • A new microextraction method combining the
Introducing a new and rapid microextraction approach based on magnetic ionic liquids: Stir bar dispersive liquid microextraction.
Chisvert, Alberto; Benedé, Juan L; Anderson, Jared L; Pierson, Stephen A; Salvador, Amparo
With the aim of contributing to the development and improvement of microextraction techniques, a novel approach combining the principles and advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) is presented. This new approach, termed stir bar dispersive liquid microextraction (SBDLME), involves the addition of a magnetic ionic liquid (MIL) and a neodymium-core magnetic stir bar into the sample allowing the MIL coat the stir bar due to physical forces (i.e., magnetism). As long as the stirring rate is maintained at low speed, the MIL resists rotational (centrifugal) forces and remains on the stir bar surface in a manner closely resembling SBSE. By increasing the stirring rate, the rotational forces surpass the magnetic field and the MIL disperses into the sample solution in a similar manner to DLLME. After extraction, the stirring is stopped and the MIL returns to the stir bar without the requirement of an additional external magnetic field. The MIL-coated stir bar containing the preconcentrated analytes is thermally desorbed directly into a gas chromatographic system coupled to a mass spectrometric detector (TD-GC-MS). This novel approach opens new insights into the microextraction field, by using the benefits provided by SBSE and DLLME simultaneously, such as automated thermal desorption and high surface contact area, respectively, but most importantly, it enables the use of tailor-made solvents (i.e., MILs). To prove its utility, SBDLME has been used in the extraction of lipophilic organic UV filters from environmental water samples as model analytical application with excellent analytical features in terms of linearity, enrichment factors (67-791), limits of detection (low ng L -1 ), intra- and inter-day repeatability (RSD<15%) and relative recoveries (87-113%, 91-117% and 89-115% for river, sea and swimming pool water samples, respectively). Copyright © 2017 Elsevier B.V. All rights reserved.
The analysis of aroma/flavor compounds in green tea using ice concentration linked with extractive stirrer.
Alluhayb, Abdullah H; Logue, Brian A
Worldwide, green tea is one of the most popular beverages. It promotes blood circulation, liver function, and lowers the risk of cancer and cardiovascular diseases. This drink is characterized by the distinctive odors and flavors produced by its constituent compounds, with its value predicated on the amount and type of constituents extracted from the tea leaves during brewing. Ice concentration linked with extractive stirrer (ICECLES) is a novel sample preparation technique, especially applicable for the extraction of relatively polar compounds while retaining excellent extraction efficiencies for non-polar compounds. In this study, ICECLES was used to prepare green tea for analysis of aroma/flavor compounds by gas chromatography-mass spectrometry (GC-MS). ICECLES performed very well, revealing 301 constituents as compared to 245 for SBSE (i.e., 56 more constituents were detected via ICECLES). Moreover, ICECLES produced stronger signal to noise ratios for all except 4 of 301 constituents, with a maximum signal enhancement of 19. Of the constituents which were only detectable using ICECLES, some very important aroma/flavor and/or medicinal compounds were easily identified, including furfural, furfural alcohol, maltol, eugenol, 2-methylpyrazine, phenethyl alcohol, 2,6-dimethoxyphenol, and α-terpineol. Overall, we confirmed that ICECLES sample preparation followed by GC-MS consistently allowed more complete green tea aroma/flavor analysis, especially for relatively polar compounds, some of which are critical for flavor quality. Copyright © 2017 Elsevier B.V. All rights reserved.
Determination of Endocrine Disrupting Compounds in surface waters by means of chromatographic techniques coupled to mass spectrometry
Directory of Open Access Journals (Sweden)
M. Di Carro
Full Text Available Two analytical methods were developed to study five endocrine disrupting compounds (4-n-nonylphenol, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol in waters. One method includes a fast liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS analysis, while the second comprise a Stir Bar Sorptive Extraction (SBSE followed by a headspace derivatization and gaschromatography-mass spectrometry (GC-MS analysis. Passive samplers POCIS (Polar Organic Chemical Integrative Samplers were used as sampling and preconcentration steps in order to reach the very low levels of the analytes in environmental waters. Both methods were then applied to the determination of the analytes in different water samples.
Quantitative analysis of fragrance in selectable one dimensional or two dimensional gas chromatography-mass spectrometry with simultaneous detection of multiple detectors in single injection.
Tan, Hui Peng; Wan, Tow Shi; Min, Christina Liew Shu; Osborne, Murray; Ng, Khim Hui
A selectable one-dimensional ((1)D) or two-dimensional ((2)D) gas chromatography-mass spectrometry (GC-MS) system coupled with flame ionization detector (FID) and olfactory detection port (ODP) was employed in this study to analyze perfume oil and fragrance in shower gel. A split/splitless (SSL) injector and a programmable temperature vaporization (PTV) injector are connected via a 2-way splitter of capillary flow technology (CFT) in this selectable (1)D/(2)D GC-MS/FID/ODP system to facilitate liquid sample injections and thermal desorption (TD) for stir bar sorptive extraction (SBSE) technique, respectively. The dual-linked injectors set-up enable the use of two different injector ports (one at a time) in single sequence run without having to relocate the (1)D capillary column from one inlet to another. Target analytes were separated in (1)D GC-MS/FID/ODP and followed by further separation of co-elution mixture from (1)D in (2)D GC-MS/FID/ODP in single injection without any instrumental reconfiguration. A (1)D/(2)D quantitative analysis method was developed and validated for its repeatability - tR; calculated linear retention indices (LRI); response ratio in both MS and FID signal, limit of detection (LOD), limit of quantitation (LOQ), as well as linearity over a concentration range. The method was successfully applied in quantitative analysis of perfume solution at different concentration level (RSD≤0.01%, n=5) and shower gel spiked with perfume at different dosages (RSD≤0.04%, n=5) with good recovery (96-103% for SSL injection; 94-107% for stir bar sorptive extraction-thermal desorption (SBSE-TD). Copyright © 2014 Elsevier B.V. All rights reserved.
Polydimethylsiloxane rod extraction, a novel technique for the determination of organic micropollutants in water samples by thermal desorption-capillary gas chromatography-mass spectrometry.
Montero, L; Popp, P; Paschke, A; Pawliszyn, J
A novel, simple and inexpensive approach to absorptive extraction of organic compounds from environmental samples is presented. It consists of a polydimethylsiloxane rod used as an extraction media, enriched with analytes during shaking, then thermally desorbed and analyzed by GC-MS. Its performance was illustrated and evaluated for the enrichment of sub- to ng/l of selected chlorinated compounds (chlorobenzenes and polychlorinated biphenyls) in water samples. The new approach was compared to the stir bar sorptive extraction performance. A natural ground water sample from Bitterfeld, Germany, was also extracted using both methods, showing good agreement. The proposed approach presented good linearity, high sensitivity, good blank levels and recoveries comparable to stir bars, together with advantages such as simplicity, lower cost and higher feasibility.
Development of a sensitive determination method for benzotriazole UV stabilizers in enviromental water samples with stir bar sorption extraction and liquid desorption prior to ultra-high performance liquid chromatography with tandem mass spectrometry.
Montesdeoca-Esponda, Sarah; del Toro-Moreno, Adrián; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan
Benzotriazole UV stabilizers are emerging compounds used in personal care products and can enter surface water after passing through wastewater treatment plants without being removed. Because these analytes are strongly hydrophobic, there is an environmental risk of accumulation in solid matrices and magnification through the trophic chain. In this work, a method based on stir bar sorption extraction with liquid desorption is presented for the extraction of benzotriazole UV stabilizers from water samples. Stir bar sorptive extraction was combined with ultra-high performance LC with MS/MS detection. All important factors affecting the stir bar sorptive extraction procedure are discussed, and the optimized method was applied to seawater and wastewater samples from Gran Canaria Island, providing good selectivity and sensitivity with LODs and limits of quantification in the range of 18.4-55.1 and 61.5-184 ng/L, respectively. Recoveries between 68.4-92.2% were achieved for the more polar compounds, whereas the recoveries were lower for the two less polar compounds, most likely due to their strong absorption into the polydimethylsiloxane stir bar phase that does not allows the complete desorption. The repeatability studies gave RSDs of between 6.45 and 12.6% for all compounds in the real samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Recent Trends in Microextraction Techniques Employed in Analytical and Bioanalytical Sample Preparation
Directory of Open Access Journals (Sweden)
Abuzar Kabir
Full Text Available Sample preparation has been recognized as a major step in the chemical analysis workflow. As such, substantial efforts have been made in recent years to simplify the overall sample preparation process. Major focusses of these efforts have included miniaturization of the extraction device; minimizing/eliminating toxic and hazardous organic solvent consumption; eliminating sample pre-treatment and post-treatment steps; reducing the sample volume requirement; reducing extraction equilibrium time, maximizing extraction efficiency etc. All these improved attributes are congruent with the Green Analytical Chemistry (GAC principles. Classical sample preparation techniques such as solid phase extraction (SPE and liquid-liquid extraction (LLE are being rapidly replaced with emerging miniaturized and environmentally friendly techniques such as Solid Phase Micro Extraction (SPME, Stir bar Sorptive Extraction (SBSE, Micro Extraction by Packed Sorbent (MEPS, Fabric Phase Sorptive Extraction (FPSE, and Dispersive Liquid-Liquid Micro Extraction (DLLME. In addition to the development of many new generic extraction sorbents in recent years, a large number of molecularly imprinted polymers (MIPs created using different template molecules have also enriched the large cache of microextraction sorbents. Application of nanoparticles as high-performance extraction sorbents has undoubtedly elevated the extraction efficiency and method sensitivity of modern chromatographic analyses to a new level. Combining magnetic nanoparticles with many microextraction sorbents has opened up new possibilities to extract target analytes from sample matrices containing high volumes of matrix interferents. The aim of the current review is to critically audit the progress of microextraction techniques in recent years, which has indisputably transformed the analytical chemistry practices, from biological and therapeutic drug monitoring to the environmental field; from foods to phyto
Supercritical fluid extraction (SFE) and gas chromatographic (GC) analysis of products from irradiated foods containing fat
International Nuclear Information System (INIS)
Adam, S.T.
Official analytical methods specify the use of organic liquid solvents which may be hazardous to human health. Non-toxic chlorinated fluorocarbons (CFC) which are still recommended for extracting soil samples are known to be detrimental to the stratospheric ozone layer and therefore subject to the ''FCKW-Halon-Verbots-Verordnung''. Therefore, alternative extraction methods using solvents in the supercritical state are currently being developed (Supercritical Fluid Extraction (SFE)). Their low viscosity and the high diffusivity of solutes in the fluids allow selective, efficient and timesaving extractions. Carbon dioxide (CO 2 ) is the fluid of choice in many applications because its critical parameters permit mild operating conditions. CO 2 of high purity is available at low cost, it is neither inflammable nor explosive, physiologically harmless and part of natural cycle processes. Furthermore, it is simply removed from the matrix without any residues left. The combination of SFE and sorptive collection of the extracted substances has been found to lead to high enrichment factors for the analytes. Distillative concentration and solid phase elution steps, required in the classical solvent extraction procedure, are no longer necessary. Loss of analytes occurring in cryogenic or solvent traps is completeley avoided. Plugging of the restrictor as a consequence of the Joule Thomson effect was not observed in the presented method. (orig./vhe)
International Nuclear Information System (INIS)
Rendall, J.S.; Cahalan, M.J.
A process is described for extracting at least two desired constituents from a mineral, using a liquid reagent which produces the constituents, or compounds thereof, in separable form and independently extracting those constituents, or compounds. The process is especially valuable for the extraction of phosphoric acid and metal values from acidulated phosphate rock, the slurry being contacted with selective extractants for phosphoric acid and metal (e.g. uranium) values. In an example, uranium values are oxidized to uranyl form and extracted using an ion exchange resin. (U.K.)
Energy Technology Data Exchange (ETDEWEB)
Coombs, D.M.; Latimer, E.G.
It is an object of this invention to provide for the demetallization and general upgrading of heavy oil via a solvent extracton process, and to improve the efficiency of solvent extraction operations. The yield and demetallization of product oil form heavy high-metal content oil is maximized by solvent extractions which employ either or all of the following techniques: premixing of a minor amount of the solvent with feed and using countercurrent flow for the remaining solvent; use of certain solvent/free ratios; use of segmental baffle tray extraction column internals and the proper extraction column residence time. The solvent premix/countercurrent flow feature of the invention substantially improves extractions where temperatures and pressures above the critical point of the solvent are used. By using this technique, a greater yield of extract oil can be obtained at the same metals content or a lower metals-containing extract oil product can be obtained at the same yield. Furthermore, the premixing of part of the solvent with the feed before countercurrent extraction gives high extract oil yields and high quality demetallization. The solvent/feed ratio features of the invention substanially lower the captial and operating costs for such processes while not suffering a loss in selectivity for metals rejection. The column internals and rsidence time features of the invention further improve the extractor metals rejection at a constant yield or allow for an increase in extract oil yield at a constant extract oil metals content. 13 figs., 3 tabs.
Fission Product Sorptivity in Graphite
Energy Technology Data Exchange (ETDEWEB)
Tompson, Jr., Robert V. [Univ. of Missouri, Columbia, MO (United States); Loyalka, Sudarshan [Univ. of Missouri, Columbia, MO (United States); Ghosh, Tushar [Univ. of Missouri, Columbia, MO (United States); Viswanath, Dabir [Univ. of Missouri, Columbia, MO (United States); Walton, Kyle [Univ. of Missouri, Columbia, MO (United States); Haffner, Robert [Univ. of Missouri, Columbia, MO (United States)
Both adsorption and absorption (sorption) of fission product (FP) gases on/into graphite are issues of interest in very high temperature reactors (VHTRs). In the original proposal, we proposed to use packed beds of graphite particles to measure sorption at a variety of temperatures and to use an electrodynamic balance (EDB) to measure sorption onto single graphite particles (a few μm in diameter) at room temperature. The use of packed beds at elevated temperature is not an issue. However, the TPOC requested revision of this initial proposal to included single particle measurements at elevated temperatures up to 1100 °C. To accommodate the desire of NEUP to extend the single particle EDB measurements to elevated temperatures it was necessary to significantly revise the plan and the budget. These revisions were approved. In the EDB method, we levitate a single graphite particle (the size, surface characteristics, morphology, purity, and composition of the particle can be varied) or agglomerate in the balance and measure the sorption of species by observing the changes in mass. This process involves the use of an electron stepping technique to measure the total charge on a particle which, in conjunction with the measured suspension voltages for the particle, allows for determinations of mass and, hence, of mass changes which then correspond to measurements of sorption. Accommodating elevated temperatures with this type of system required a significant system redesign and required additional time that ultimately was not available. These constraints also meant that the grant had to focus on fewer species as a result. Overall, the extension of the original proposed single particle work to elevated temperatures added greatly to the complexity of the proposed project and added greatly to the time that would eventually be required as well. This means that the bulk of the experimental progress was made using the packed bed sorption systems. Only being able to recruit one graduate student meant that data acquisition with the packed bed systems ended up competing for the graduate student's available time with the electrodynamic balance redesign and assembly portions of the project. This competition for available time was eventually mitigated to some extent by the later recruitment of an undergraduate student to help with data collection using the packed bed system. It was only the recruitment of the second student that allowed the single particle balance design and construction efforts to proceed as far as they did during the project period. It should be added that some significant time was also spent by the graduate student cataloging previous work involving graphite. This eventually resulted in a review paper being submitted and accepted ("Adsorption of Iodine on Graphite in High Temperature Gas-Cooled Reactor Systems: A Review," Kyle L. Walton, Tushar K. Ghosh, Dabir S. Viswanath, Sudarshan K. Loyalka, Robert V. Tompson). Our specific revised objectives in this project were as follows: Experimentally obtain isotherms of Iodine for reactor grade IG-110 samples of graphite particles over a range of temperatures and pressures using an EDB and a temperature controlled EDB; Experimentally obtain isotherms of Iodine for reactor grade IG-110 samples of graphite particles over a range of temperatures and pressures using a packed column bed apparatus; Explore the effect that charge has on the adsorption isotherms of iodine by varying the charges on and the voltages used to suspend the microscopic particles in the EDB; and To interpret these results in terms of the existing models (Langmuir, BET, Freundlich, and others) which we will modify as necessary to include charge related effects.
International Nuclear Information System (INIS)
Stary, J.; Kyrs, M.; Navratil, J.; Havelka, S.; Hala, J.
Definitions of the basic terms and of relations are given and the knowledge is described of the possibilities of the extraction of elements, oxides, covalent-bound halogenides and heteropolyacids. Greatest attention is devoted to the detailed analysis of the extraction of chelates and ion associates using diverse agents. For both types of compounds detailed conditions are given of the separation and the effects of the individual factors are listed. Attention is also devoted to extractions using mixtures of organic agents, the synergic effects thereof, and to extractions in non-aqueous solvents. The effects of radiation on extraction and the main types of apparatus used for extractions carried out in the laboratory are described. (L.K.)
DEFF Research Database (Denmark)
Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne
Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two-part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validation of the developed OSATS scale for vac...
DEFF Research Database (Denmark)
Huang, Chuixiu; Chen, Zhiliang; Gjelstad, Astrid
Electromembrane extraction (EME) was inspired by solid-phase microextraction and developed from hollow fiber liquid-phase microextraction in 2006 by applying an electric field over the supported liquid membrane (SLM). EME provides rapid extraction, efficient sample clean-up and selectivity based...
Applying no-depletion equilibrium sampling and full-depletion bioaccessibility extraction to 35 historically polycyclic aromatic hydrocarbon contaminated soils
DEFF Research Database (Denmark)
Bartolomé, Nora; Hilber, Isabel; Sosa, Dayana
Assessing the bioaccessibility of organic pollutants in contaminated soils is considered a complement to measurements of total concentrations in risk assessment and legislation. Consequently, methods for its quantification require validation with historically contaminated soils. In this study, 35...... with polyoxymethylene was used to determine freely dissolved concentrations (Cfree) of polycyclic aromatic hydrocarbons (PAHs), while sorptive bioaccessibility extraction (SBE) with silicone rods was used to determine the bioaccessible PAH concentrations (Cbioacc) of these soils. The organic carbon partition...... Capacity Ratio (SCR); particularly for soils with very high KD. The source of contamination determined bioaccessible fractions (fbioacc). The smallest fbioacc were obtained with skeet soils (15%), followed by the pyrogenically influenced soils, rural soils, and finally, the petrogenically contaminated soil...
Application of modified stir bar with nickel:zinc sulphide nanoparticles loaded on activated carbon as a sorbent for preconcentration of losartan and valsartan and their determination by high performance liquid chromatography.
Pebdani, Arezou Amiri; Dadfarnia, Shayesteh; Shabani, Ali Mohammad Haji; Khodadoust, Saeid; Haghgoo, Soheila
In this study, the stir bar was coated for the first time with the nicel:zins sulphide nanoparticles (Ni:ZnS NPs) loaded on activated carbon (AC) (Ni:ZnS-AC) as well as 1-ethyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) using sol gel technique and was used for stir bar sorptive extraction (SBSE) of losartan (LOS) and valsartan (VAL) as the model compounds. The extracted analytes were then quantified by high performance liquid chromatography (HPLC) equipped with an ultra violet detector. The best extraction performance for LOS and VAL was obtained through the optimization of the parameters affecting SBSE including pH of sample solution, ionic strength, extraction time, volume of desorption solvent, desorption time, and stirring speed. The fractional factorial design (FFD) was used to find the most important parameters, which were then optimized by the central composite design (CCD) and the desirability function (DF). Under the optimal experimental conditions, wide linear ranges of 0.4-50μgL(-1) and 0.5-50μgL(-1) and good RSDs (at level of 5μgL(-1) and n=6) of 4.4 and 4.9% were obtained for LOS and VAL, respectively. With the enrichment factors (EFs) of 188.6 and 184.8-fold, the limits of detection (LODs, S/N=3) of the developed method were found to be 0.12 and 0.15μgL(-1) for LOS and VAL, respectively. The developed method was successfully applied to the determination of LOS and VAL in urine and plasma matrices. Copyright © 2016 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Kalnins, J.G.; Krebs, G.; Tekawa, M.; Cowles, D.; Byrne, T.
This report will describe some of the general features of the Bevatron extraction system, primarily the dependence of the beam parameters and extraction magnet currents on the Bevalac field. The extraction magnets considered are: PFW, XPl, XP2, XS1, XS2, XM1, XM2, XM3, XQ3A and X03B. This study is based on 84 past tunes (from 1987 to the present) of various ions (p,He,O,Ne,Si,S,Ar,Ca,Ti,Fe,Nb,La,Au and U), for Bevalac fields from 1.749 to 12.575 kG, where all tunes included a complete set of beam line wire chamber pictures. The circulating beam intensity inside the Bevalac is measured with Beam Induction Electrodes (BIE) in the South Tangent Tank. The extracted beam intensity is usually measured with the Secondary Emission Monitor (SEM) in the F1-Box. For most of the tunes the extraction efficiency, as given by the SEM/BIE ratio, was not recorded in the MCR Log Book, but plotting the available Log Book data as a function of the Bevalac field, see Fig.9, we find that the extraction efficiency is typically between 30->60% with feedback spill
Trace determination of volatile polycyclic aromatic hydrocarbons in natural waters by magnetic ionic liquid-based stir bar dispersive liquid microextraction.
Benedé, Juan L; Anderson, Jared L; Chisvert, Alberto
In this work, a novel hybrid approach called stir bar dispersive liquid microextraction (SBDLME) that combines the advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) has been employed for the accurate and sensitive determination of ten polycyclic aromatic hydrocarbons (PAHs) in natural water samples. The extraction is carried out using a neodymium stir bar magnetically coated with a magnetic ionic liquid (MIL) as extraction device, in such a way that the MIL is dispersed into the solution at high stirring rates. Once the stirring is ceased, the MIL is magnetically retrieved onto the stir bar, and subsequently subjected to thermal desorption (TD) coupled to a gas chromatography-mass spectrometry (GC-MS) system. The main parameters involved in TD, as well as in the extraction step affecting the extraction efficiency (i.e., MIL amount, extraction time and ionic strength) were evaluated. Under the optimized conditions, the method was successfully validated showing good linearity, limits of detection and quantification in the low ng L -1 level, good intra- and inter-day repeatability (RSD < 13%) and good enrichment factors (18 - 717). This sensitive analytical method was applied to the determination of trace amounts of PAHs in three natural water samples (river, tap and rainwater) with satisfactory relative recovery values (84-115%), highlighting that the matrices under consideration do not affect the extraction process. Copyright © 2017 Elsevier B.V. All rights reserved.
Dietzenbacher, Erik; Lahr, Michael L.
In this paper, we generalize hypothetical extraction techniques. We suggest that the effect of certain economic phenomena can be measured by removing them from an input-output (I-O) table and by rebalancing the set of I-O accounts. The difference between the two sets of accounts yields the
Comparison of active and passive sampling strategies for the monitoring of pesticide contamination in streams
Assoumani, Azziz; Margoum, Christelle; Guillemain, Céline; Coquery, Marina
constants (Rs). Each constant links the mass of the a target contaminant accumulated in the sampler to its concentration in water. At the end of the field application, the Rs are used to calculate the TWA concentration of each target contaminant with the final mass of the contaminants accumulated in the sampler. Stir Bar Sorptive Extraction (SBSE) is a solvent free sample preparation technique dedicated to the analysis of moderately hydrophobic to hydrophobic compounds in liquid and gas samples. It is composed of a magnet enclosed in a glass tube coated with a thick film of polydimethysiloxane (PDMS). We recently developed the in situ application of SBSE as a passive sampling technique (herein named "Passive SBSE") for the monitoring of agricultural pesticides. The aim of this study is to perform the calibration of the passive SBSE in the laboratory, and to apply and compare this technique to active sampling strategies for the monitoring of 16 relatively hydrophobic to hydrophobic pesticides in streams, during 2 1-month sampling campaigns. Time-weighted averaged concentrations of the target pesticides obtained from passive SBSE were compared to the target pesticide concentrations of grab samples, and time-related and flow-dependent samples of the streams. Results showed passive SBSE as an efficient alternative to conventional active sampling strategies.
Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry.
Spietelun, Agata; Marcinkowski, Łukasz; de la Guardia, Miguel; Namieśnik, Jacek
Solid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about novel methodological and instrumental solutions in relation to different variants of solid phase extraction techniques, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE) and magnetic solid phase extraction (MSPE) is presented, including practical applications of these techniques and a critical discussion about their advantages and disadvantages. The proposed solutions fulfill the requirements resulting from the concept of sustainable development, and specifically from the implementation of green chemistry principles in analytical laboratories. Therefore, particular attention was paid to the description of possible uses of novel, selective stationary phases in extraction techniques, inter alia, polymeric ionic liquids, carbon nanotubes, and silica- and carbon-based sorbents. The methodological solutions, together with properly matched sampling devices for collecting analytes from samples with varying matrix composition, enable us to reduce the number of errors during the sample preparation prior to chromatographic analysis as well as to limit the negative impact of this analytical step on the natural environment and the health of laboratory employees. Copyright © 2013 Elsevier B.V. All rights reserved.
Solid-phase extraction element based on epoxy polymer monolith for determination of polar organic compounds in aqueous media.
Takahashi, Tadashi; Odagiri, Kayo; Watanabe, Atsushi; Watanabe, Chuichi; Kubo, Takuya; Hosoya, Ken
A solid-phase extraction element based on epoxy polymer monolith was fabricated for sorptive enrichment of polar compounds from liquid and gaseous samples. After ultrasonication of the element in an aqueous solution for a given period of time, the thermal desorption (TD) using a pyrolyzer with gas chromatography/mass spectrometry (GC/MS), in which TD temperature was programmed from 50 to 250 °C for the analytes absorbed in the element, was used to evaluate the element for basic extraction performance using the aqueous standard mixtures consisting of compounds having varied polarities such as hexanol, isoamyl acetate, linalool, furfural and decanoic acid, in concentrations ranging from 10 μg/L to 1 mg/L. Excellent linear relationships were observed for all compounds in the standard mixture, except decanoic acid. In the extraction of beverages such as red wine, the extraction element showed stronger adsorption characteristics for polar compounds such as alcohols and acids than a non-polar polydimethylsiloxane-based element. This feature is derived from the main polymer structure along with hydroxyl and amino groups present in the epoxy-based monolith polymer matrix. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Directory of Open Access Journals (Sweden)
Full Text Available Dois métodos, utilizando permeâmetros a disco, foram usados para medir a sorvidade e a condutividade hidráulica em três horizontes de um solo de Santa Maria da Boa Vista, Pernambuco, utilizando-se potenciais de fornecimento de água de 0, -2,5, -5 e -10 cm de água. No primeiro método, a condutividade hidráulica foi obtida através de estimativas da sorvidade e do fluxo estacionário, utilizando-se apenas um permeâmetro. No segundo, as medidas da sorvidade e da condutividade hidráulica foram feitas utilizando-se valores dos fluxos estacionários, obtidos a partir de dois permeâmetros de diferentes raios. Esse segundo método apresentou resultados mais consistentes dos tempos -- gravitacional e geométrico --, e do raio característico de poros que o primeiro método. A sorvidade foi tão importante quanto a condutividade hidráulica para caracterizar o processo de infiltração. A redução brusca dos valores dos raios característicos de poros do horizonte A2/B, com mudanças no potencial de fornecimento de água, revelou a heterogeneidade da estrutura deste horizonte, permitindo identificar a influência dos volumes argilosos compactados sobre o processo de infiltração.Sorptivity and hydraulic conductivity were determined by two methods using disc permeameters. Infiltration experiments were carried out on three horizons of a representative soil of the semi-arid region, located in Santa Maria da Boa Vista, State of Pernambuco, Brazil. Water was supplied to this soil by disc permeameters at potentials of 0, -2.5, -5 and -10 cm of water. In the first method, hydraulic conductivity was measured using estimates of sorptivity and steady state fluxes. In the second, sorptivity and hydraulic conductivity were determined using measurements of steady state fluxes with two disc permeameters of different radius. Results of the second method, regarding characteristic times and characteristic pore radius, were more consistent than those of the
Energy Technology Data Exchange (ETDEWEB)
Patart, G
In the hydrogenation or extraction of by-products from organic substances at high temperatures and pressures, the gases or liquids, or both, used are those which are already heated and compressed during industrial operations such as exothermic synthesizing reactions such as the production of methanol from hydrogen and carbon monoxide in a catalytic process. Gases from this reaction may be passed upwardly through a digester packed with pine wood while liquid from the same catalytic process is passed downwardly through the material. The issuing liquid contains methanol, pine oil, acetone, isopropyl alcohol, and acetic acid. The gases contain additional hydrogen, carbon monoxide, methane, ethylene, and its homologs which are condensed upon the catalyser to liquid hydrocarbons. Petroleum oils and coal may be treated similarly.
Extraction of trace nitrophenols in environmental water samples using boronate affinity sorbent
International Nuclear Information System (INIS)
Zhang, Yong; Mei, Meng; Huang, Xiaojia; Yuan, Dongxing
cake sorptive extraction (SCSE). • The B–N coordination favored the extraction of nitrophenols pollutants. • Method of sensitive monitoring of nitrophenols in water samples was developed.
Soil-borne polycyclic aromatic hydrocarbons in El Paso, Texas: Analysis of a potential problem in the United States/Mexico border region
De La Torre-Roche, Roberto J.; Lee, Wen-Yee; Campos-Díaz, Sandra I.
Ultrasonic extraction followed by Stir Bar Sorptive Extraction (SBSE) and thermal desorption inline coupled with Gas Chromatography and Mass Spectrometry (TD/GC/MS)was used to perform a comprehensive determination of soil-borne polycyclic aromatic hydrocarbons (PAHs) in El Paso, Texas. The method provided good sensitivity and faster processing time for the analysis. The total PAHs in El Paso soil ranged from 0.1 to 2225.5 µg kg−1. Although the majority of PAH concentrations did not exceed the soil screening levels regulated by the United States Environmental Protection Agency, the existence of PAHs in this ecosystem is ubiquitous. Naphthalene were found in 100% of the soil samples; while the heavy PAHs (five- and six-ring) were not often detected and mostly remained in closer proximity to industrial areas and major traffic points. The results ruled out the possibility of petroleum refining as the significant source of local soil-borne PAH contamination, but they suggested that the PAHs found in El Paso soil were closely linked to human activities and possible other industrial processes. PMID:18768257
Differences between Lipids Extracted from Five Species Are Not Sufficient To Explain Biomagnification of Nonpolar Organic Chemicals
DEFF Research Database (Denmark)
Jahnke, Annika; Holmbäck, Jan; Andersson, Rina Argelia
headspace from spiked olive oil to determine their sorptive capacities. Lipids from seal blubber and pork bacon solely composed of triglycerides had capacities similar to that of olive oil; lipids from mussels, herring, and guillemot egg had quantifiable fractions of phospholipids and cholesterol and showed...... capacities reduced by factors of up to 2.3-fold. Generally, the sorptive capacities of the lipids were not elevated relative to the olive oil controls and are unlikely to explain a substantial part of biomagnification....
Sorptive removal of arsenate using termite mound.
Fufa, Fekadu; Alemayehu, Esayas; Lennartz, Bernd
Long-term consumption of arsenic results in severe and permanent health damages. The aim of the study was to investigate arsenate (As(V)) sorption capacity of termite mound (TM), containing mainly silicon, aluminum, iron and titanium oxides, under batch adsorption setup. The pattern of As(V) removal with varying contact time, solution pH, adsorbent dose, As(V) concentration and competing anions was investigated. Dissolution of the adsorbent was insignificant under the equilibrium conditions. Equilibrium was achieved within 40 min of agitation time. Kinetic data of As(V) adsorption followed well the pseudo-second order equation (R(2) > 0.99). High As(V) removal efficiency (∼ 99%) was observed over a pH range ∼ 3-∼ 10, which is of great importance in the practical application. The Freundlich and Dubinin-Radushkevich isotherms well described (R(2) > 0.99, χ(2) ∼ 0.05) the equilibrium As(V) adsorption, giving a coefficient of adsorption 1.48 mg(1-1/n)L(1/n)/g and a saturation capacity 13.50 mg/g respectively. The obtained value of mean sorption energy (EDR = 13.32 kJ/mol) suggested the chemisorption mechanism of As(V) adsorption on TM. The removal of As(V) was significantly decreased in the presence of phosphate ions. The As(V) loaded adsorbent was successfully regenerated using NaOH solution with insignificant loss of metals. Therefore, the results of the study demonstrated that TM could be considered as a promising adsorbent for the treatment of As(V) in drinking water. Copyright © 2013 Elsevier Ltd. All rights reserved.
Sorptive removal of ciprofloxacin hydrochloride from simulated ...
African Journals Online (AJOL)
particles were highly porous with average pore diameter of nearly 10 μm. The optimum pH and ..... Moisture content. 8.6%. 8. Porosity. 94.6%. 9 .... The slope and intercept of ln(qe−qt) versus t plots can be used to determine k1 and qe.
Post-acquisition data processing for the screening of transformation products of different organic contaminants. Two-year monitoring of river water using LC-ESI-QTOF-MS and GCxGC-EI-TOF-MS.
López, S Herrera; Ulaszewska, M M; Hernando, M D; Martínez Bueno, M J; Gómez, M J; Fernández-Alba, A R
This study describes a comprehensive strategy for detecting and elucidating the chemical structures of expected and unexpected transformation products (TPs) from chemicals found in river water and effluent wastewater samples, using liquid chromatography coupled to electrospray ionization quadrupole-time-of-flight mass spectrometer (LC-ESI-QTOF-MS), with post-acquisition data processing and an automated search using an in-house database. The efficacy of the mass defect filtering (MDF) approach to screen metabolites from common biotransformation pathways was tested, and it was shown to be sufficiently sensitive and applicable for detecting metabolites in environmental samples. Four omeprazole metabolites and two venlafaxine metabolites were identified in river water samples. This paper reports the analytical results obtained during 2 years of monitoring, carried out at eight sampling points along the Henares River (Spain). Multiresidue monitoring, for targeted analysis, includes a group of 122 chemicals, amongst which are pharmaceuticals, personal care products, pesticides and PAHs. For this purpose, two analytical methods were used based on direct injection with a LC-ESI-QTOF-MS system and stir bar sorptive extraction (SBSE) with bi-dimensional gas chromatography coupled with a time-of-flight spectrometer (GCxGC-EI-TOF-MS).
Comprehensive authentication of (E)-alpha(beta)-ionone from raspberries, using constant flow MDGC-C/P-IRMS and enantio-MDGC-MS.
Sewenig, Sabine; Bullinger, Dino; Hener, Uwe; Mosandl, Armin
A new coupling system of GC-GC, connected via a Multi Column Switching Device MCS2 for measuring isotope ratios, is introduced. By means of several standard substances the precise and accurate measurement of isotopic values is proved. First applications concerning the authentication of raspberry aroma compounds are established. Consequently, the combination of constant flow multidimensional gas chromatography-combustion/pyrolysis-isotope ratio mass spectrometry (MDGC-C/P-IRMS) is applied to the authenticity assessment of (E)-alpha(beta)-ionone from six different raspberry cultivars. Furthermore, 12 commercially available raspberry products and samples of (E)-alpha(beta)-ionone, some declared to be natural, are investigated. delta(2)Eta(V)(-)(SMOW) and delta(13)C(V)(-)(PDB) values of (E)-alpha(beta)-ionone are determined, and characteristic authenticity ranges were concluded from raspberries by correlation of both delta(2)Eta(V)(-)(SMOW) and delta(13)C( V)(-)(PDB) values. The results are correlated with the determination of enantiomeric purities of (E)-alpha-ionone, using stir bar sorptive extraction enantio-multidimensional gas chromatography mass spectrometry (SBSE-enantio-MDGC-MS).
Automated headspace solid-phase dynamic extraction to analyse the volatile fraction of food matrices.
Bicchi, Carlo; Cordero, Chiara; Liberto, Erica; Rubiolo, Patrizia; Sgorbini, Barbara
High concentration capacity headspace techniques (headspace solid-phase microextraction (HS-SPME) and headspace sorptive extraction (HSSE)) are a bridge between static and dynamic headspace, since they give high concentration factors as does dynamic headspace (D-HS), and are as easy to apply and as reproducible as static headspace (S-HS). In 2000, Chromtech (Idstein, Germany) introduced an inside-needle technique for vapour and liquid sampling, solid-phase dynamic extraction (SPDE), also known as "the magic needle". In SPDE, analytes are concentrated on a 50 microm film of polydimethylsiloxane (PDMS) and activated carbon (10%) coated onto the inside wall of the stainless steel needle (5 cm) of a 2.5 ml gas tight syringe. When SPDE is used for headspace sampling (HS-SPDE), a fixed volume of the headspace of the sample under investigation is sucked up an appropriate number of times with the gas tight syringe and an analyte amount suitable for a reliable GC or GC-MS analysis accumulates in the polymer coating the needle wall. This article describes the preliminary results of both a study on the optimisation of sampling parameters conditioning HS-SPDE recovery, through the analysis of a standard mixture of highly volatile compounds (beta-pinene, isoamyl acetate and linalool) and of the HS-SPDE-GC-MS analyses of aromatic plants and food matrices. This study shows that HS-SPDE is a successful technique for HS-sampling with high concentration capability, good repeatability and intermediate precision, also when it is compared to HS-SPME.
Extract of Acanthospermum hispidum
African Journals Online (AJOL)
quantitatively. Acute toxicity study of the extract was conducted, and diabetic rats induced using alloxan (80 mg/kg ... Type 2 diabetes is one of the leading causes of mortality and ..... (2011): Phytochemical screening and extraction - A review.
Extracts against Various Pathogens
Directory of Open Access Journals (Sweden)
Ritika Chauhan
The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens.
using Supercritical Fluid Extraction
African Journals Online (AJOL)
Methods: Supercritical CO2 extraction technology was adopted in this experiment to study the process of extraction of volatile oil from Polygonatum odoratum while gas chromatograph-mass spectrometer ..... Saponin rich fractions from.
Lemmond, Tracy D; Hanley, William G; Guensche, Joseph Wendell; Perry, Nathan C; Nitao, John J; Kidwell, Paul Brandon; Boakye, Kofi Agyeman; Glaser, Ron E; Prenger, Ryan James
An information extraction system and methods of operating the system are provided. In particular, an information extraction system for performing meta-extraction of named entities of people, organizations, and locations as well as relationships and events from text documents are described herein.
An improved hollow fiber solvent-stir bar microextraction for the preconcentration of anabolic steroids in biological matrix with determination by gas chromatography-mass spectrometry.
Liu, Wei; Zhang, Lan; Fan, Liangbiao; Lin, Zian; Cai, Yimin; Wei, Zhenyi; Chen, Guonan
In this paper, a convenient and self-assembled hollow fiber solvent-stir bar microextraction (HF-SSBME) device was developed, which could stir by itself. In the extraction process, the proposed device made the solvent "bar" not floating at the sample solution and exposing to air while organic solvents outside hollow fiber always wrapped with donor phase solvent, which reduced the vaporization of organic solvents. This design could improve the precisions and recoveries of experiments. For evaluating the device, seven anabolic steroids (prasterone, 5α-androstane-3α, 17β-diol, methandriol, 19-norandrostenediol, androstenediol, methyltestosterone and methandienone) were used as model analytes and extraction conditions such as type and volume of organic solvents, agitation speed, extraction time, extraction temperature and salt addition were studied in detail. Under the optimum conditions (15 μL toluene, 40 °C, stirring at 750 rpm for 30 min with 1.5 g sodium chloride addition in 20.0 mL donor phase), the linear ranges of anabolic steroids were 0.25-200 ng mL(-1) with gas chromatography-mass spectrometry. The limits of detection were lower than 0.10 ng mL(-1). The recoveries and precisions in spiked urine and hair samples were between 73.97-93.56% and 2.18-4.47% (n=5). HF-SSBME method combined the intrinsical merits of hollow fiber with the superiority of the proposed self-stirring device which can be developed to two-phase, three-phase and in situ derivatization modes with wide prospect of application. Besides, the pedestal of this proposed device can be converted to fix stir bar in stir bar sorptive extraction (SBSE) method. Copyright © 2012 Elsevier B.V. All rights reserved.
Extraction with supercritical gases
Energy Technology Data Exchange (ETDEWEB)
Schneider, G M; Wilke, G; Stahl, E
The contents of this book derives from a symposium on the 5th and 6th of June 1978 in the ''Haus der Technik'' in Essen. Contributions were made to separation with supercritical gases, fluid extraction of hops, spices and tobacco, physicochemical principles of extraction, phase equilibria and critical curves of binary ammonia-hydrocarbon mixtures, a quick method for the microanalytical evaluation of the dissolving power of supercritical gases, chromatography with supercritical fluids, the separation of nonvolatile substances by means of compressed gases in countercurrent processes, large-scale industrial plant for extraction with supercritical gases, development and design of plant for high-pressure extraction of natural products.
Exhaustive extraction of peptides by electromembrane extraction
DEFF Research Database (Denmark)
Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig
trifluoroacetate, and leu-enkephalin were extracted from 600 μL of 25 mM phosphate buffer (pH 3.5), through a supported liquid membrane (SLM) containing di-(2-ethylhexyl)-phosphate (DEHP) dissolved in an organic solvent, and into 600 μL of an acidified aqueous acceptor solution using a thin flat membrane-based EME...
DEFF Research Database (Denmark)
A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme.......A method for producing a plant extract comprises incubating a plant material with an enzyme composition comprising a lipolytic enzyme....
AGS slow extraction improvements
International Nuclear Information System (INIS)
Glenn, J.W.; Smith, G.A.; Sandberg, J.N.; Repeta, L.; Weisberg, H.
Improvement of the straightness of the F5 copper septum increased the AGS slow extraction efficiency from approx. 80% to approx. 90%. Installation of an electrostatic septum at H2O, 24 betatron wavelengths upstream of F5, further improved the extraction efficiency to approx. 97%
Energy Technology Data Exchange (ETDEWEB)
Dalton, R F
Metal values (especially uranium values) are extracted from aqueous solutions of metal oxyions in the absence of halogen ion using an imidazole of defined formula. Especially preferred extractants are 1-alkyl imidazoles and benzimidazoles having from 7 to 25 carbon atoms in the alkyl group.
African Journals Online (AJOL)
Purpose: To evaluate the larvicidal, nematicidal, antifeedant, and antifungal effects of 10 solvent extracts of Mentha spicata root. Methods: Ten solvent extracts were investigated for their total flavonoid and phenolic content and screened for larvicidal, nematicidal, antifeedant, and antifungal activities. The total phenolic ...
Microextraction Techniques Coupled to Liquid Chromatography with Mass Spectrometry for the Determination of Organic Micropollutants in Environmental Water Samples
Directory of Open Access Journals (Sweden)
Mª Esther Torres Padrón
Full Text Available Until recently, sample preparation was carried out using traditional techniques, such as liquid–liquid extraction (LLE, that use large volumes of organic solvents. Solid-phase extraction (SPE uses much less solvent than LLE, although the volume can still be significant. These preparation methods are expensive, time-consuming and environmentally unfriendly. Recently, a great effort has been made to develop new analytical methodologies able to perform direct analyses using miniaturised equipment, thereby achieving high enrichment factors, minimising solvent consumption and reducing waste. These microextraction techniques improve the performance during sample preparation, particularly in complex water environmental samples, such as wastewaters, surface and ground waters, tap waters, sea and river waters. Liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS and time-of-flight mass spectrometric (TOF/MS techniques can be used when analysing a broad range of organic micropollutants. Before separating and detecting these compounds in environmental samples, the target analytes must be extracted and pre-concentrated to make them detectable. In this work, we review the most recent applications of microextraction preparation techniques in different water environmental matrices to determine organic micropollutants: solid-phase microextraction SPME, in-tube solid-phase microextraction (IT-SPME, stir bar sorptive extraction (SBSE and liquid-phase microextraction (LPME. Several groups of compounds are considered organic micropollutants because these are being released continuously into the environment. Many of these compounds are considered emerging contaminants. These analytes are generally compounds that are not covered by the existing regulations and are now detected more frequently in different environmental compartments. Pharmaceuticals, surfactants, personal care products and other chemicals are considered micropollutants. These
Evaluation of ionic liquids supported on silica as a sorbent for fully automated online solid-phase extraction with LC-MS determination of sulfonamides in bovine milk samples.
da Silva, Meire Ribeiro; Mauro Lanças, Fernando
Sulfonamides are antibiotics widely used in the treatment of diseases in dairy cattle. However, their indiscriminate use for disease control may lead to their presence in tissues and milk and their determination requires a sample preparation step as part of an analytical approach. Among the several sample preparation techniques available, those based upon the use of sorptive materials have been widely employed. Recently, the application of ionic liquids immobilized on silica surfaces or polymeric materials has been evaluated for such an application. This manuscript addresses the evaluation of silica-based ionic liquid obtained by a sol-gel synthesis process by basic catalysis as sorbent for online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry for sulfonamides determination. Infrared vibrational spectroscopy confirmed the presence of the ionic liquid on the silica surface, suggesting that the ionic liquid was anchored on to the silica surface. Other sorbents varying the ionic liquid alkyl chain were also synthesized and evaluated by off-line solid-phase extraction in the sulfonamide extraction. As the length of the alkyl chain increased, the amount of extracted sulfonamides decreased, possibly due to a decrease in the electrostatic interaction caused by the reduction in the polarity, as well as the presence of a hexafluorophosphate anion that increases the hydrophobic character of the material. The use of 1-butyl-3-methylimidazolium hexafluorophosphate as a selective ionic liquid sorbent enabled the isolation and sulfonamide preconcentration in bovine milk by online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The limit of quantification for the method developed was 5-7, 5 μg/mL, with extraction recoveries ranging between 74 and 93% and intra- and interassay between 1.5-12.5 and 2.3-13.1, respectively. © 2018 WILEY-VCH Verlag Gmb
Extraction chromatography of actinides
International Nuclear Information System (INIS)
Muller, W.
Extraction chromatography of actinides in the oxidation state from 2 to 6 is reviewed. Data on using neutral (tbp), basic (substituted ammonium salts) and acidic [di-(2-ethylhexyl)-phosphoric acid (D2EHPA)] extracting agents ketones, esters, alcohols and β-diketones in this method are given. Using the example of actinide separation using D2EHPA, discussed are factors influencing the efficiency of their chromatography separation (nature and particle size of the carrier materials, extracting agents amount on the carrier, temperature and elution rate)
Multimedia Information Extraction
Maybury, Mark T
The advent of increasingly large consumer collections of audio (e.g., iTunes), imagery (e.g., Flickr), and video (e.g., YouTube) is driving a need not only for multimedia retrieval but also information extraction from and across media. Furthermore, industrial and government collections fuel requirements for stock media access, media preservation, broadcast news retrieval, identity management, and video surveillance. While significant advances have been made in language processing for information extraction from unstructured multilingual text and extraction of objects from imagery and vid
The organophosphorus extractants
International Nuclear Information System (INIS)
Zaoul, B.; Attou, M.; Azzouz, A.
This work consists in a bibliographic review dealing with phosphorus and organophosphorus compounds chemistry and especially with the main extracting agents used in uranium ore treatment. In this context, a special interest is devoted to TBP, D 2 EHPA and TOPO. The content of this work is based on a large bibliography including cca. One hundred references related to many aspects concerning as well the nomenclature, the classification and the chemical structures of the organophosphorus compounds as synthesis methods, purification and analysis of the main extracting agents used in uranium extraction
Substoichiometric extraction of phosphorus
International Nuclear Information System (INIS)
Shigematsu, T.; Kudo, K.
A study of the substoichiometric extraction of phosphorus is described. Phosphorus was extracted in the form of ternary compounds such as ammonium phosphomolybdate, 8-hydroxyquinolinium phosphomolybdate, tetraphenylarsonium phosphomolybdate and tri-n-octylamine phosphomolybdate. Consequently, phosphorus was extracted substoichiometrically by the addition of a substoichiometric amount of molybdenum for the four phosphomolybdate compounds. On the other hand, phosphorus could be separated substoichiometrically with a substoichiometric amount of tetraphenylarsonium chloride or tri-n-octylamine. Stoichiometric ratios of these ternary compounds obtained substoichiometrically were 1:12:3 for phosphorus, molybdenum and organic reagent. The applicability of these compounds to phosphorus determination is also discussed. (author)
Considerations on ultra-trace analysis of phthalates in drinking water.
Serôdio, P; Nogueira, J M F
Stir bar sorptive extraction with liquid desorption followed by large volume injection and capillary gas chromatography coupled to mass spectrometry (SBSE-LD/LVI-GC-MS), had been applied for the determination of ultra-traces of seven-phthalates (dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate) in drinking water samples, which are included in the priority lists set by several international regulatory organizations. Instrumental calibration under the selected-ion monitoring mode acquisition (LVI-GC-MS(SIM)), experimental parameters that could affect the SBSE-LD efficiency, as well as, the control of the contamination profile are fully discussed. Throughout systematic assays on 30 mL water samples spiked at the 0.40 microg/L level, it had been established that stir bars coated with 47 microL of polydimethylsiloxane, an equilibrium time of 60 min (1,000 rpm) and methanol as back extraction solvent, allowed the best analytical performance to monitor phthalates in water matrices. From the data obtained, good accuracy and a remarkable reproducibility (water partition coefficients (K(PDMS/W) approximately K(O/W)), with the exception of bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate, for which lower yields were measured. Additionally, a remarkable linear dynamic range between 25 and 2,000 ng/L (r(2)>0.99) and low detection limits (3-40 ng/L) were also achieved for the seven-phthalates studied. The application of the present method to monitor phthalates in tap and bottled mineral water samples, allowed convenient selectivity and high sensitivity up to 1.0 microg/L level, using the standard addition methodology. The proposed method showed to be feasible and sensitive with a low sample volume requirement to monitor phthalates in drinking water matrices at the ultra-trace level, in compliance with international regulatory
Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms
International Nuclear Information System (INIS)
Andrade, Natasha A.; Centofanti, Tiziana; McConnell, Laura L.; Hapeman, Cathleen J.; Torrents, Alba; Nguyen, Anh; Beyer, W. Nelson; Chaney, Rufus L.; Novak, Jeffrey M.; Anderson, Marya O.; Cantrell, Keri B.
Improved approaches are needed to assess bioavailability of hydrophobic organic compounds in contaminated soils. Performance of thin-film solid-phase extraction (TF-SPE) using vials coated with ethylene vinyl acetate was compared to earthworm bioassay (Lumbricus terrestris). A DDT and dieldrin contaminated soil was amended with four organic carbon materials to assess the change in bioavailability. Addition of organic carbon significantly lowered bioavailability for all compounds except for 4,4′-DDT. Equilibrium concentrations of compounds in the polymer were correlated with uptake by earthworms after 48d exposure (R 2 = 0.97; p 40yr of aging. Results show that TF-SPE can be useful in examining potential risks associated with contaminated soils and to test effectiveness of remediation efforts. -- Highlights: • Bioavailability of pesticides in soil were assessed using TF-SPE and earthworms. • Soil from a historical orchard was used to examine aged residues of dieldrin and DDT. • TF-SPE results were strongly correlated with earthworm bioaccumulation factors. • Ethylene vinyl acetate polymer has sorptive capacity similar to earthworm lipid. • TF-SPE useful to estimate bioavailability of hydrophobic organic pesticides in soil. -- Capsule A thin-film polymer sampler proved to be efficient in estimating the differences in bioavailability to earthworms in a soil treated with organic amendments
Hydroalcohol Fruit Peel Extract
African Journals Online (AJOL)
L) fruit peel using 80 % ethanol-induced gastric ulcer model in rats. Methods: Male ... Conclusion: The study shows indicates the antiulcer properties of the methanol extracts of north white ... experimentation, Cimetidine was obtained from.
African Journals Online (AJOL)
2Department of Science Laboratory Technology, Hussaini Adamu Federal Polytechnic, Kazaure ... Powdered leaves of Carica papaya (L.) were extracted with ethanol and partitioned in .... about 15 minutes indicated the presence of saponins.
Comparison of mentha extracts obtained by different extraction methods
Directory of Open Access Journals (Sweden)
Milić Slavica
Full Text Available The different methods of mentha extraction, such as steam distillation, extraction by methylene chloride (Soxhlet extraction and supercritical fluid extraction (SFE by carbon dioxide (CO J were investigated. SFE by CO, was performed at pressure of 100 bar and temperature of40°C. The extraction yield, as well as qualitative and quantitative composition of obtained extracts, determined by GC-MS method, were compared.
Gold mineralogy and extraction
Energy Technology Data Exchange (ETDEWEB)
Cashion, J.D.; Brown, L.J. [Monash University, Physics Department (Australia)
Several examples are examined in which Moessbauer spectroscopic analysis of gold mineral samples, treated concentrates and extracted species has provided information not obtainable by competing techniques. Descriptions are given of current work on bacterial oxidation of pyritic ores and on the adsorbed species from gold extracted from cyanide and chloride solutions onto activated carbon and polyurethane foams. The potential benefits for the gold mining industry from Moessbauer studies and some limitations on the use of the technique are also discussed.
Gold mineralogy and extraction
International Nuclear Information System (INIS)
Cashion, J.D.; Brown, L.J.
Several examples are examined in which Moessbauer spectroscopic analysis of gold mineral samples, treated concentrates and extracted species has provided information not obtainable by competing techniques. Descriptions are given of current work on bacterial oxidation of pyritic ores and on the adsorbed species from gold extracted from cyanide and chloride solutions onto activated carbon and polyurethane foams. The potential benefits for the gold mining industry from Moessbauer studies and some limitations on the use of the technique are also discussed
Kalvas, T.
This chapter gives an introduction to low-energy beam transport systems, and discusses the typically used magnetostatic elements (solenoid, dipoles and quadrupoles) and electrostatic elements (einzel lens, dipoles and quadrupoles). The ion beam emittance, beam space-charge effects and the physics of ion source extraction are introduced. Typical computer codes for analysing and designing ion optical systems are mentioned, and the trajectory tracking method most often used for extraction simulations is described in more detail.
Tevatron extraction microcomputer
International Nuclear Information System (INIS)
Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.; Batavia, IL)
Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper (1) summarizes performance
Tevatron extraction microcomputer
International Nuclear Information System (INIS)
Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.
Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper summarizes performance
Isoflavones hydrolisis and extraction
Directory of Open Access Journals (Sweden)
Jozilene Fernandes Farias dos Santos
Full Text Available Isoflavones are found in leguminous species and are used as phytoestrogens widely used by industry for its beneficial effects as estrogens mimicked, antioxidant action and anti-cancer activity. The identification and quantification of isoflavones in plants is a need due to the high demand of industry. Several methods are used for its extraction, using organic solvents (methanol, ethanol and acetonitrile. Samples from five legumes species from Instituto de Zootecnia (IZ, Forage Gene Bank were tested. All seeds received a hydrothermic treatment immersed in pure water at 50°C for 12 hours. Seeds were then oven-dryed. In this work we tested the extraction using only the hydrothermic treatment and hyfrothermic treatment allied to methanol extaction protocol. Seeds were grinded and half of the samples were ressuspended in PBS (phosphate Buffer and the other half were submited to 4 mL of methanol and 1% of acetic acid, soaked for 5 hours, shaked every 15 minutes, at room temperature. The five legume species that we quantify isoflavones by enzyme immunoassay (EIA were: Calopogonium mucunoides, Bauhinia sp., Cajanus cajan, Galactia martii, Leucaena leucocephala. The extraction procedure is a recomendation of AOAC (Association of Official Analytical Chemists for isoflavone quantification. Ours results show an increase of extraction using methanol 80% plus acetic acid 1% and was obtained using solvent extraction in comparison to hydrothermic procedure alone (figure 1.
Ultrasound-Assisted Extraction: Effect of Extraction Time and Solvent ...
African Journals Online (AJOL)
Purpose: To investigate the influence of extraction conditions assisted by ultrasound on the quality of extracts obtained from Mesembryanthemum edule shoots. Methods: The extraction procedure was carried out in an ultrasonic bath. The effect of two solvents (methanol and ethanol) and two extraction times (5 and 10 min) ...
Substoichiometric extraction of chromium
International Nuclear Information System (INIS)
Shigematsu, T.; Kudo, K.
Substoichiometric extraction of chromium with tetraphenylarsonium chloride (TPACl), tri-n-octylamine (TNOA), diethylammonium diethyldithiocarbamate (DDDC) and ammonium pyrrolidinedithiocarbamate (APDC) was examined in detail. Chromium can be extracted substoichiometrically in a pH range, which is 1.1-2.6 for the TPACl compound, 0.6-2.3 for the TNOA compound, 5.1-6.4 for the DDDC chelate and 3.9-4.9 for the APDC chelate. Chromium in high-purity calcium carbonate, Orchard Leaves (NBS SRM-1571) and Brewers Yeast (NBS SRM-1569) was determined by neutron activation analysis combined with substoichiometric extraction by DDDC and APDC. The values of 2.0+-0.02 ppm and 2.6+-0.2 ppm were obtained for Brewers Yeast and Orchard Leaves, respectively. These values were in good agreement with those reported by NBS. The reaction mechanism and the reaction ratio between hexavalent chromium and dithiocarbamate are also discussed. (author)
Genotoxicity of plant extracts
Directory of Open Access Journals (Sweden)
Vera M. F. Vargas
Full Text Available Aqueous extracts of seven species used in Brazilian popular medicine (Achyrocline satureoides, Iodina rhombifolia, Desmodium incanum, Baccharis anomala, Tibouchina asperior, Luehea divaricata, Maytenus ilicifolia were screened to the presence of mutagenic activity in the Ames test (Salmonella/microsome. Positive results were obtained for A. satureoides, B anomala and L. divaricata with microsomal activation. As shown elsewhere (Vargas et al., 1990 the metabolites of A. satureoides extract also show the capacity to induce prophage and/or SOS response in microscreen phage induction assay and SOS spot chromotest.
Nano-electromembrane extraction
DEFF Research Database (Denmark)
Payán, María D Ramos; Li, Bin; Petersen, Nickolaj J.
as extraction selectivity. Compared with conventional EME, the acceptor phase volume in nano-EME was down-scaled by a factor of more than 1000. This resulted in a very high enrichment capacity. With loperamide as an example, an enrichment factor exceeding 500 was obtained in only 5 min of extraction...... electrophoresis (CE). In that way the sample preparation performed by nano-EME was coupled directly with a CE separation. Separation performance of 42,000-193,000 theoretical plates could easily be obtained by this direct sample preparation and injection technique that both provided enrichment as well...
International Nuclear Information System (INIS)
Kesler, S.B.; Fahrbach, D.O.E.
Rossing Uranium Ltd. operates a large open pit uranium mine and extraction plant at a remote site in the Namib desert. Production started at the plant in 1978. A ferric leach process was introduced later, and the new leach plant began commissioning in October 1981. The process has proved to be reliable and easily controlled. Ferric iron is supplied through recovery from the acid plant calcine, and levels can be maintained above the design levels. Leach extractions were increased more than expected when this process was adopted, and the throughput has been considerably reduced, allowing cost savings in mining and milling
Extraction spectrophotometric analyzer
International Nuclear Information System (INIS)
Batik, J.; Vitha, F.
Automation is discussed of extraction spectrophotometric determination of uranium in a solution. Uranium is extracted from accompanying elements in an HCl medium with a solution of tributyl phosphate in benzene. The determination is performed by measuring absorbance at 655 nm in a single-phase ethanol-water-benzene-tributyl phosphate medium. The design is described of an analyzer consisting of an analytical unit and a control unit. The analyzer performance promises increased productivity of labour, improved operating and hygiene conditions, and mainly more accurate results of analyses. (J.C.)
Extraction Methods, Variability Encountered in
Bodelier, P.L.E.; Nelson, K.E.
Synonyms Bias in DNA extractions methods; Variation in DNA extraction methods Definition The variability in extraction methods is defined as differences in quality and quantity of DNA observed using various extraction protocols, leading to differences in outcome of microbial community composition
... Greece people have used grapes, grape leaves, and sap for health purposes. Grape seed extract was developed ... sharing research results, and educating the public. Its resources include publications (such as Dietary ... Department of Health & Human Services, National Institutes of Health, National Center for ...
CERN PhotoLab
SPS long straight section (LSS) with a series of 5 septum tanks for slow extraction (view in the direction of the proton beam). There are 2 of these: in LSS2, towards the N-Area; in LSS6 towards the W-Area. See also Annual Report 1975, p.175.
CERN PhotoLab
One of the 3-m long electrostatics septa. The septum itself consists of 0.15 mm thick molybdenum wires with a 1.5 mm pitch. Each of the two SPS extraction systems will contain four of these electrostatic septa.
LEAR: antiproton extraction lines
Photographic Service
Antiprotons, decelerated in LEAR to a momentum of 100 MeV/c (kinetic energy of 5.3 MeV), were delivered to the experiments in an "Ultra-Slow Extraction", dispensing some 1E9 antiprotons over times counted in hours. Beam-splitters and a multitude of beam-lines allowed several users to be supplied simultaneously.
Concepts for immobilized extractants
International Nuclear Information System (INIS)
Paine, R.T.
This paper addresses the problem of cleaning actinides from geomedia. In the past actinides were often released to the ground because of their tendency to bind tightly to forms of geomedia, and in addition spills have occurred over time. To remediate these areas involves finding ways to either guarantee the retention of the actinides in the geomedia, or finding ways to extract them and leave the soils clean. One possible way to clean soils is to wash them, which in order to extract actinides means the use of ligands which bind competitively with actinides in the presence of soil fractions. An array of organic ligands is known which bind with actinides, but the larger problem of handling these ligands in a manner which allows concentration of the actinides is still open. The author addresses work to bind such ligands to different types of matrices which can then be used in packed extraction columns to remove actindes from flow streams, and finally concentrated, by using minimal volume backflushing to extract the actinides from the column
Uranium extraction from phosphoric acid
International Nuclear Information System (INIS)
Araujo Figueiredo, C. de
The recovery of uranium from phosphoric liquor by two extraction process is studied. First, uranium is reduced to tetravalent condition and is extracted by dioctypyrophosphoric acid. The re-extraction is made by concentrated phosphoric acid with an oxidizing agent. The re-extract is submitted to the second process and uranium is extracted by di-ethylhexilphosphoric acid and trioctylphosphine oxide. (M.A.C.) [pt
Automated Water Extraction Index
DEFF Research Database (Denmark)
Feyisa, Gudina Legese; Meilby, Henrik; Fensholt, Rasmus
Classifying surface cover types and analyzing changes are among the most common applications of remote sensing. One of the most basic classification tasks is to distinguish water bodies from dry land surfaces. Landsat imagery is among the most widely used sources of data in remote sensing of water...... resources; and although several techniques of surface water extraction using Landsat data are described in the literature, their application is constrained by low accuracy in various situations. Besides, with the use of techniques such as single band thresholding and two-band indices, identifying...... an appropriate threshold yielding the highest possible accuracy is a challenging and time consuming task, as threshold values vary with location and time of image acquisition. The purpose of this study was therefore to devise an index that consistently improves water extraction accuracy in the presence...
Extractable Work from Correlations
Directory of Open Access Journals (Sweden)
Martí Perarnau-Llobet
Full Text Available Work and quantum correlations are two fundamental resources in thermodynamics and quantum information theory. In this work, we study how to use correlations among quantum systems to optimally store work. We analyze this question for isolated quantum ensembles, where the work can be naturally divided into two contributions: a local contribution from each system and a global contribution originating from correlations among systems. We focus on the latter and consider quantum systems that are locally thermal, thus from which any extractable work can only come from correlations. We compute the maximum extractable work for general entangled states, separable states, and states with fixed entropy. Our results show that while entanglement gives an advantage for small quantum ensembles, this gain vanishes for a large number of systems.
Apparatus for extracting petroleum
Energy Technology Data Exchange (ETDEWEB)
Coogan, J
An apparatus for extracting petroleum from petroleum bearing sand or shale is described comprising a container for liquids, the container being divided into a plurality of compartments, an agitator mounted within the container and below the liquid level and having its forward end opening into one of the compartments, means for delivering sand or shale to the forward end of the agitator, means for subjecting the sand or shale to the action of a solvent for the petroleum while the sand or shale is being agitated and is submerged, the first-mentioned compartment being adapted to receive the extracted petroleum and means for removing the treated sand or shale from adjacent the rear end of the agitator.
Solid phase extraction membrane
Carlson, Kurt C [Nashville, TN; Langer, Roger L [Hudson, WI
A wet-laid, porous solid phase extraction sheet material that contains both active particles and binder and that possesses excellent wet strength is described. The binder is present in a relatively small amount while the particles are present in a relatively large amount. The sheet material is sufficiently strong and flexible so as to be pleatable so that, for example, it can be used in a cartridge device.
International Nuclear Information System (INIS)
James, G.S.; Davidson, R.J.
A process for extracting gold and uranium from an ore containing them both comprising the steps of pulping the finely comminuted ore with a suitable cyanide solution at an alkaline pH, acidifying the pulp for uranium dissolution, adding carbon activated for gold recovery to the pulp at a suitable stage, separating the loaded activated carbon from the pulp, and recovering gold from the activated carbon and uranium from solution
Extractive metallurgy. Recent advances
International Nuclear Information System (INIS)
Stevenson, E.J.
Detailed technical information derived from patents issued since 1975 on extractive metallurgy is presented. In part one, concerning copper, the major areas covered are: smelting and roasting; acid leaching; ammonia leach processes; cuprous chloride and ferric chloride; and recovery of copper values from solution. Part two covers other metals, including: nickel and cobalt; ocean floor nodules; lead, zinc, molybdenum and manganese; precious metals; and uranium titanium, tantalum, rhenium, gallium, and other metals
International Nuclear Information System (INIS)
Middleton, P.; Smith, J.R.
In pulsed columns for use in solvent extraction processes, e.g. the reprocessing of nuclear fuel, the horizontal perforated plates inside the column are separated by interplate spacers manufactured from metallic neutron absorbing material. The spacer may be in the form of a spiral or concentric circles separated by radial limbs, or may be of egg-box construction. Suitable neutron absorbing materials include stainless steel containing boron or gadolinium, hafnium metal or alloys of hafnium. (UK)
Influence of Extraction Parameters on Hydroalcohol Extracts of the ...
African Journals Online (AJOL)
The parameter that had the greatest influence on extraction process was alcohol concentration ... rules and processing steps [2]. As part .... Table 1: Extractive batch nnumbers with the respective factors and levels studied in the factorial design.
Plant extracts as radioprotectors
Energy Technology Data Exchange (ETDEWEB)
Baydoun, S; Al-Oudat, M [Atomic Energy Commission, Department of Radiation Protection and Nuclear Safety, Damascus (Syrian Arab Republic); Al-Achkar, W [Atomic Energy Commission, Department of Radiobiology and Health, Damascus (Syrian Arab Republic)
Several studies show that the extracts of some plants, namely containing vitamins or sulfide components, have radioprotection properties against the effects of ionizing radiation. In Syria, many of hates plants are available. This experiment was conducted in order to test the ability of ten different plants to protect against the radiation damages. These plants are Daucus carota L., Brassica oleracea L, Aloe vera L., Opuntia ficus-indica, Allium cepa L., Capsicum annuum L., Scilla maritima L., Allium sativum L., Rubus sanctus L. and Rosa canina L.Their effects on the protection of E. Coli growth after the exposure to L.D 50 of gamma radiation (100 Gy) were investigated . Two concentrations to each plant extract were tested, both were than 1%. Our results are indicating that the protection depend on plant. The radioprotection factors were ranged between 1.42 to 2.39. The best results were obtained by using the extract of Allium sativum L. (2.01), Opuntia ficus-indica (2.14) and Capsiucum annuum L. (2.39). (author) 16 refs., 2 tabs., 4 figs.
Plant extracts as radioprotectors
International Nuclear Information System (INIS)
Baydoun, S.; Al-Oudat, M.; Al-Achkar, W.
Several studies show that the extracts of some plants, namely containing vitamins or sulfide components, have radioprotection properties against the effects of ionizing radiation. In Syria, many of hates plants are available. This experiment was conducted in order to test the ability of ten different plants to protect against the radiation damages. These plants are Daucus carota L., Brassica oleracea L, Aloe vera L., Opuntia ficus-indica, Allium cepa L., Capsicum annuum L., Scilla maritima L., Allium sativum L., Rubus sanctus L. and Rosa canina L.Their effects on the protection of E. Coli growth after the exposure to L.D 50 of gamma radiation (100 Gy) were investigated . Two concentrations to each plant extract were tested, both were than 1%. Our results are indicating that the protection depend on plant. The radioprotection factors were ranged between 1.42 to 2.39. The best results were obtained by using the extract of Allium sativum L. (2.01), Opuntia ficus-indica (2.14) and Capsiucum annuum L. (2.39). (author) 16 refs., 2 tabs., 4 figs
Plant extracts as radioprotectors
International Nuclear Information System (INIS)
Baydoun, S.; Al-Oudat, M.; Al-Achkar, W.
Several studies show that the extracts of some plants, namely containing vitamins or sulfide components, have radioprotection properties against the effects of ionizing radiation. In Syria, many of hates plants are available. This experiment was conducted in order to test the ability of ten different plants to protect against the radiation damages. These plants are Daucus carota L., Brassica oleracea L, Aloe vera L., Opuntia ficus-indica, Allium cepa L., Capsicum annuum L., Scilla maritima L., Allium sativum L., Rubus sanctus L. and Rosa canina L.Their effects on the protection of E. Coli growth after the exposure to L.D 50 of gamma radiation (100 Gy) were investigated . Two concentrations to each plant extract were tested, both were than 1%. Our results are indicating that the protection depend on plant. The radioprotection factors were ranged between 1.42 to 2.39. The best results were obtained by using the extract of Allium sativum L. (2.01), Opuntia ficus-indica (2.14) and Capsiucum annuum L. (2.39). (author)
Solvent extraction of zirconium
International Nuclear Information System (INIS)
Kim, S.S.; Yoon, J.H.
The extraction of zirconium(VI) from an aqueous solution of constant ionic strength with versatic acid-10 dissolved in benzen was studied as a function of pH and the concentration of zirconium(VI) and organic acid. The effects of sulphate and chlorine ions on the extraction of the zirconium(VI) were briefly examined. It was revealed that (ZrOR 2 .2RH) is the predominant species of extracted zirconium(VI) in the versatic acid-10. The chemical equation and the apparent equilibrium constants thereof have been determined as follows. (ZrOsup(2+))aq+ 2(R 2 H 2 )sub(org) = (ZrOR 2 .2RH)sub(org)+2(H + )aq Ksub(Zr) = (ZrOR 2 .2RH)sub(org)(H + ) 2 /(ZrOsup(2+))sub(aq)(R 2 H 2 )sup(2)sub(org) = 3.3 x 10 -7 . The synergistic effects of TBP and D2EHPA were also studied. In the mixed solvent with 0.1M TBP, the synergistic effect was observed, while the mixed solvent with D2EHPA showed the antisynergistic effect. (Author)
Directory of Open Access Journals (Sweden)
Y. I. Korenman
Full Text Available The extraction of mono azo dyes E102, E122, E110, E124, E129 from aqueous solutions with hydrophilic solvents (alcohols, esters, ketones and polymers (poly-N-vinylamides, polyethylene glycol was studied. The main regularities of extraction are established. The distribution coefficients and degree of extraction of dyes was estimate. The influence of the nature of solvents and polymers on the extraction of dyes from aqueous solutions are established.
Understanding extractive bleed : wood extractives: distribution, properties, and classes
Edward Burke; Norm Slavik; Tony Bonura; Dennis Connelly; Tom Faris; Arnie Nebelsick; Brent Stuart; Sam Williams; Alex C. Wiedenhoeft
Color, odor, and natural durability of heartwood are characteristics imparted by a class of chemicals in wood known collectively extractives. Wood is converted by the tree from sapwood to heartwood by the deposition of extractives, typically many years after the growth ring undergoing this change was formed by the tree. Extractives are thus not a part of the wood...
African Journals Online (AJOL)
sensitivity tests of crude extract fractions of the plant extracts using ethanol, chloroform, methanol, petroleum ether, water and ethyl acetate were investigated on nine bacterial isolates. .... These were obtained by punching the filter paper with.
Dynamics of Agricultural Groundwater Extraction
Hellegers, P.J.G.J.; Zilberman, D.; Ierland, van E.C.
Agricultural shallow groundwater extraction can result in desiccation of neighbouring nature reserves and degradation of groundwater quality in the Netherlands, whereas both externalities are often not considered when agricultural groundwater extraction patterns are being determined. A model is
Improvements in solvent extraction columns
International Nuclear Information System (INIS)
Aughwane, K.R.
Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)
Directory of Open Access Journals (Sweden)
Monica Popescu
Full Text Available Marine bioactive substances extracted from seaweed are currently used in food, animal feed, as a raw material in the industry and have therapeutic applications. Most of the products based on marine algae are extracted from Brown algae Ascophyllum nodosum. The use of extracts of seaweed in agriculture is beneficial because the amount of chemical fertilizers and obtaining organic yield.
On extraction reagents for hydrometallurgy
International Nuclear Information System (INIS)
Zolotov, Yu.A.
Fundamental requirements to the extractants are considered. Ways of obtaining selective extractants are discussed in particular on the basis of coordination chemistry achivements. Attention is drawn to expediency of study (as extractants) of flotation reagents, additions to the oil, pesticides, accelerators of caoutchouc vulcanization
Challenges in Managing Information Extraction
Shen, Warren H.
This dissertation studies information extraction (IE), the problem of extracting structured information from unstructured data. Example IE tasks include extracting person names from news articles, product information from e-commerce Web pages, street addresses from emails, and names of emerging music bands from blogs. IE is all increasingly…
Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely
Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the "flat" organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of search
Directory of Open Access Journals (Sweden)
Gergely Tibély
Full Text Available Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the "flat" organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of
Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely
Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the "flat" organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of search. Moreover
Resinous constituent extracting process
Energy Technology Data Exchange (ETDEWEB)
Sayer, W F
The method of recovering oily constituents from coal or oil shale comprising the saturation of coal or oil shale in a sealed vessel with an organic solution having a boiling point at atmospheric pressure of not exceeding 220/sup 0/C, elevating the temperature within the vessel to a temperature below the cracking temperature of the constituents and maintaining the pressure within the vessel below 51 pounds, to extract the oily material from the coal or oil shale and subsequently separating the solvent from the oily material.
Microbiological metal extraction processes
International Nuclear Information System (INIS)
Torma, A.E.
Application of biotechnological principles in the mineral processing, especially in hydrometallurgy, has created new opportunities and challenges for these industries. During the 1950's and 60's, the mining wastes and unused complex mineral resources have been successfully treated in bacterial assisted heap and dump leaching processes for copper and uranium. The interest in bio-leaching processes is the consequence of economic advantages associated with these techniques. For example, copper can be produced from mining wastes for about 1/3 to 1/2 of the costs of copper production by the conventional smelting process from high-grade sulfide concentrates. The economic viability of bio leaching technology lead to its world wide acceptance by the extractive industries. During 1970's this technology grew into a more structured discipline called 'bio hydrometallurgy'. Currently, bio leaching techniques are ready to be used, in addition to copper and uranium, for the extraction of cobalt, nickel, zinc, precious metals and for the desulfurization of high-sulfur content pyritic coals. As a developing technology, the microbiological leaching of the less common and rare metals has yet to reach commercial maturity. However, the research in this area is very active. In addition, in a foreseeable future the biotechnological methods may be applied also for the treatment of high-grade ores and mineral concentrates using adapted native and/or genetically engineered microorganisms. (author)
Carcinogenicity of soil extracts
Energy Technology Data Exchange (ETDEWEB)
Shcherbak, N P
A total of 270 3-mo-old mice, hybrids of the C57BL and CBA strains which are highly susceptible to carcinogens, were painted on the skin (2-3 admin./week) with 3-4 drops of (1) a concentrated benzene extract of soil taken near a petroleum refinery with a 3,4 benzpyrene (BP) content of 0.22%; (2) a 0.22% soln of pure BP in benzene; (3) a concentrated benzene extract of soil taken from an old residential area of Moscow (BP content 0.0004%); (4) a 0.0004% BP soln in benzene; and (5) pure benzene. Only mice in the first 2 groups developed tumors. In group (1), 8 mice had papillomas, 46 had skin cancer, 1 had a sarcoma and 2 had plasmocytomas. In group (2) all 60 animals had skin cancer. Lung metastases were present at autopsy in 5 mice in group (1) and in 10 mice in group (2); in some cases, these tumors were multiple. Lymph node metastases were found in 6 mice in group (1) and in 10 mice in group (2). Tumors developed more slowly in group (1) than in group (2).
Supercritical fluid extraction of hops
Directory of Open Access Journals (Sweden)
Full Text Available Five cultivars of hop were extracted by the method of supercritical fluid extraction using carbon dioxide (SFE–CO2 as extractant. The extraction (50 g of hop sample using a CO2 flow rate of 97.725 L/h was done in the two steps: 1. extraction at 150 bar and 40°C for 2.5 h (sample of series A was obtained and, after that, the same sample of hop was extracted in the second step: 2. extraction at 300 bar and 40 °C for 2.5 h (sample of series B was obtained. The Magnum cultivar was chosen for the investigation of the extraction kinetics. For the qualitative and quantitative analysis of the obtained hop extracts, the GC-MS method was used. Two of four themost common compounds of hop aroma (a-humulene and b-caryophyllene were detected in samples of series A. In addition, isomerized a-acids and a high content of b-acids were detected. The a-acids content in the samples of series B was the highest in the extract of the Magnum cultivar (it is a bitter variety of hop. The low contents of a-acids in all the other hop samples resulted in extracts with low a-acids content, i.e., that contents were under the prescribed a-acids content.
Oxygen Extraction from Minerals
Muscatello, Tony
Oxygen, whether used as part of rocket bipropellant or for astronaut life support, is a key consumable for space exploration and commercialization. In Situ Resource Utilization (ISRU) has been proposed many times as a method for making space exploration more cost effective and sustainable. On planetary and asteroid surfaces the presence of minerals in the regolith that contain oxygen is very common, making them a potential oxygen resource. The majority of research and development for oxygen extraction from minerals has been for lunar regolith although this work would generally be applicable to regolith at other locations in space. This presentation will briefly survey the major methods investigated for oxygen extraction from regolith with a focus on the current status of those methods and possible future development pathways. The major oxygen production methods are (1) extraction from lunar ilmenite (FeTiO3) with either hydrogen or carbon monoxide, (2) carbothermal reduction of iron oxides and silicates with methane, and (3) molten regolith electrolysis (MRE) of silicates. Methods (1) and (2) have also been investigated in a two-step process using CO reduction and carbon deposition followed by carbothermal reduction. All three processes have byproducts that could also be used as resources. Hydrogen or carbon monoxide reduction produce iron metal in small amounts that could potentially be used as construction material. Carbothermal reduction also makes iron metal along with silicon metal and a glass with possible applications. MRE produces iron, silicon, aluminum, titanium, and glass, with higher silicon yields than carbothermal reduction. On Mars and possibly on some moons and asteroids, water is present in the form of mineral hydrates, hydroxyl (-OH) groups on minerals, andor water adsorbed on mineral surfaces. Heating of the minerals can liberate the water which can be electrolyzed to provide a source of oxygen as well. The chemistry of these processes, some key
International Nuclear Information System (INIS)
Josa, J.M.; Merino, J.L.
The Nuclear Fusion National Program depends on lithium supplies. Extractive metallurgy development is subordinate to the localization and evaluation of ore resources. Nowadays lithium raw materials usable with present technology consist of pegmatite ore and brine. The Instituto Geologico y Minero Espanol (IGME) found lepidolite, ambligonite and spodrimene in pegmatite ores in different areas of Spain. However, an evaluation of resources has not been made. Different Spanish surface and underground brines are to be sampled and analyzed. If none of these contain significant levels of lithium, the Junta de Energia Nuclear (JEN) will try an agreement with IGME for ENUSA (Empresa Nacional del Uranio, S.A.) to explore pegmatite-ore bodies from different locations. Different work stages, laboratory tests, pilots plants tests and commercial plant, are foreseen, if the deposits are found. (author)
International Nuclear Information System (INIS)
In 1983 the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development (OECD/NEA) and the IAEA jointly published a book on Uranium Extraction Technology. A primary objective of this report was to document the significant technological developments that took place during the 1970s. The purpose of this present publication is to update and expand the original book. It includes background information about the principle of the unit operations used in uranium ore processing and summarizes the current state of the art. The publication also seeks to preserve the technology and the operating 'know-how' developed over the past ten years. This publication is one of a series of Technical Reports on uranium ore processing that have been prepared by the Division of Nuclear Fuel Cycle and Waste Management at the IAEA. A complete list of these reports is included as an addendum. Refs, figs and tabs
Influence of Extraction Parameters on Hydroalcohol Extracts of the ...
African Journals Online (AJOL)
... the influence of alcohol concentration (50, 70 and 90 % v/v), extraction time (2, 6 and 10 h), and particle size of the herbal drug (0.25, 0.5 and 1.0 mm) on the pH, dry residue and myrsinoic acid B (MAB) content of hydroalcoholic extracts by high performance liquid chromatography (HPLC) method. Results: For the extracts, ...
Supercritical carbon dioxide hop extraction
Directory of Open Access Journals (Sweden)
Pfaf-Šovljanski Ivana I.
Full Text Available The hop of Magnum cultivar was extracted using supercritical carbon dioxide (SFE-as extractant. Extraction was carried out in the two steps: the first one being carried out at 150 bar and 40°C for 2.5 h (Extract A, and the second was the extraction of the same hop sample at 300 bar and 40°C for 2.5 h (Extract B. Extraction kinetics of the system hop-SFE-CO2 was investigated. Two of four most common compounds of hop aroma (α-humulene and β-caryophyllene were detected in Extract A. Isomerised α-acids and β-acids were detected too. a-Acid content in Extract B was high (that means it is a bitter variety of hop. Mathematical modeling using empirical model characteristic time model and simple single sphere model has been performed on Magnum cultivar extraction experimental results. Characteristic time model equations, best fitted experimental results. Empirical model equation, fitted results well, while simple single sphere model equation poorly approximated the results.
Membrane extraction instead of solvent extraction - what does it give
International Nuclear Information System (INIS)
Macasek, F.
Membrane extraction, i.e. separation in double-emulsion systems, is analyzed theoretically as a three-phase distribution process. Its efficiency is evaluated from the point of view of chemical equilibria and diffusion transport kinetics. The main advantages of membrane extraction as compared with solvent extraction are in higher yields (for preconcentration) and higher capacity for recovery of solutes. A pertraction factor and multiplication factor were defined. They are convenient parameters for numerical characterization of solute distribution, system capacity, process economics, and separation kinetics (both at a linear and non-linear extraction isotherm). 17 refs.; 4 figs
Producing ashless coal extracts by microwave irradiation
Energy Technology Data Exchange (ETDEWEB)
Ozgur Sonmez; Elife Sultan Giray [Mersin University, Mersin (Turkey). Department of Chemistry
To produce ashless coal extracts, three Turkish coals were extracted with N-methyl-2-pyrrolidinone (NMP), NMP/ethylenediamine (EDA) (17/1, vol/vol) mixture and NMP/tetralin (9/1, vol/vol) mixture through thermal extraction and microwave extraction. Solvent extraction by microwave irradiation (MI) was found to be more effective than that by thermal extraction. Extraction yield of coals in NMP enhanced by addition of a little EDA, but tetralin addition showed variances according to extraction method used. While tetralin addition caused a decrease in the thermal extraction yield, it increased the yield of the extraction by MI. Following the extraction, the solid extracts were produced with ash content ranging from 0.11% to 1.1%. Ash content of solid extract obtained from microwave extraction are less than ash contents of solid extracts obtained from thermal extraction. 34 refs., 7 figs., 5 tabs.
Uranium extraction in phosphoric acid
International Nuclear Information System (INIS)
Araujo Figueiredo, C. de
Uranium is recovered from the phosphoric liquor produced from the concentrate obtained from phosphorus-uraniferous mineral from Itataia mines (CE, Brazil). The proposed process consists of two extraction cycles. In the first one, uranium is reduced to its tetravalent state and then extracted by dioctylpyrophosphoric acid, diluted in Kerosene. Re-extraction is carried out with concentrated phosphoric acid containing an oxidising agent to convert uranium to its hexavalent state. This extract (from the first cycle) is submitted to the second cycle where uranium is extracted with DEPA-TOPO (di-2-hexylphosphoric acid/tri-n-octyl phosphine oxide) in Kerosene. The extract is then washed and uranium is backextracted and precipitated as commercial concentrate. The organic phase is recovered. Results from discontinuous tests were satisfactory, enabling to establish operational conditions for the performance of a continuous test in a micro-pilot plant. (Author) [pt
Unsymmetrical phosphate as extractant for the extraction of nitric acid
International Nuclear Information System (INIS)
Gaikwad, R.H.; Jayaram, R.V.
Tri-n-butyl phosphate (TBP) was first used as an extractant in 1944, during Manhattan project for the separation of actinides and further explored by Warf in 1949 for the extraction of Ce(IV) from aqueous nitric acid. TBP was further used as an extractant in the Plutonium Uranium Recovery by Extraction (PUREX) process. To meet the stringent requirements of the nuclear industry TBP has been extensively investigated. In spite of its wide applicability, TBP suffers from various disadvantages such as high aqueous solubility, third phase formation, chemical and radiation degradation leading to the formation of undesired products. It also suffers from incomplete decontamination of the actinides from fission products. Various attempts have been made to overcome the problems associated with TBP by way of using higher homologues of TBP such as Tri-iso amyl phosphate (TiAP), Tri-secondary butyl phosphate (TsBP), Tri amyl phosphate (TAP). It was found that in some cases the results were considerably better than those obtained with TBP for uranium/thorium extraction. The extraction of nitric acid by TBP and its higher homologues which are symmetrical are well documented. However, no solvent has emerged clearly superior than TBP. Here in we report the extraction of nitric acid with neutral unsymmetrical phosphates and study them as extractants for the extraction of nitric acid. Dibutyl secbutyl phosphate, dibutyl pentyl phosphate and dibutyl heptyl phosphate were synthesised for this purpose and the extraction of nitric acid was studied in n-dodecane. The results indicate that the substitution of one of the alkyl groups of the symmetrical phosphate adjacent to the phosphoryl (P=O) group of the phosphate does not have any pronounced effect on the extraction capacity of nitric acid. (author)
Uranium refining by solvent extraction
International Nuclear Information System (INIS)
Kraikaew, J.
The yellow cake refining was studied in both laboratory and semi-pilot scales. The process units mainly consist of dissolution and filtration, solvent extraction, and precipitation and filtration. Effect of flow ratio (organic flow rate/ aqueous flow rate) on working efficiencies of solvent extraction process was studied. Detailed studies were carried out on extraction, scrubbing and stripping processes. Purity of yellow cake product obtained is high as 90.32% U 3 O 8
New extraction technique for alkaloids
Directory of Open Access Journals (Sweden)
Djilani Abdelouaheb
Full Text Available A method of extraction of natural products has been developed. Compared with existing methods, the new technique is rapid, more efficient and consumes less solvent. Extraction of alkaloids from natural products such as Hyoscyamus muticus, Datura stramonium and Ruta graveolens consists of the use of a sonicated solution containing a surfactant as extracting agent. The alkaloids are precipitated by Mayer reagent, dissolved in an alkaline solution, and then extracted with chloroform. This article compares the results obtained with other methods showing clearly the advantages of the new method.
Directory of Open Access Journals (Sweden)
P. N. Savvin
Full Text Available Anthocyanins red pigments that give color a wide range of fruits, berries and flowers. In the food industry it is widely known as a dye a food additive E163. To extract from natural vegetable raw materials traditionally used ethanol or acidified water, but in same technologies it's unacceptable. In order to expand the use of anthocyanins as colorants and antioxidants were explored extracting pigments alcohols with different structures of the carbon skeleton, and the position and number of hydroxyl groups. For the isolation anthocyanins raw materials were extracted sequentially twice with t = 60 C for 1.5 hours. The evaluation was performed using extracts of classical spectrophotometric methods and modern express chromaticity. Color black currant extracts depends on the length of the carbon skeleton and position of the hydroxyl group, with the alcohols of normal structure have higher alcohols compared to the isomeric structure of the optical density and index of the red color component. This is due to the different ability to form hydrogen bonds when allocating anthocyanins and other intermolecular interactions. During storage blackcurrant extracts are significant structural changes recoverable pigments, which leads to a significant change in color. In this variation, the stronger the higher the length of the carbon skeleton and branched molecules extractant. Extraction polyols (ethyleneglycol, glycerol are less effective than the corresponding monohydric alcohols. However these extracts saved significantly higher because of their reducing ability at interacting with polyphenolic compounds.
Passive vapor extraction feasibility study
International Nuclear Information System (INIS)
Rohay, V.J.
Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft 3 /min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft 3 /min air flow rates, passive vapor extraction is more cost effective below 100 ppm
Supercritical fluid extraction of uranium
International Nuclear Information System (INIS)
Kumar, Pradeep
Uranium being strategic material, its separation and purification is of utmost importance in nuclear industry, for which solvent extraction is being employed. During solvent extraction significant quantity of radioactive liquid waste gets generated which is of environmental concern. In recent decades supercritical fluid extraction (SFE) has emerged as promising alternative to solvent extraction owing to its inherent advantage of reduction in liquid waste generation and simplification of process. In this paper a brief overview of research work carried out so far on SFE of uranium by BARC has been given
Sterically hindered solvent extractants
International Nuclear Information System (INIS)
Solka, J.L.; Reis, A.H. Jr.; Mason, G.W.; Lewey, S.M.; Peppard, D.F.
Di-t-pentylphosphinic acid, [C(CH 3 ) 2 (CH 2 CH 3 )] 2 PO(OH), H[Dt-PeP], has been shown by single-crystal X-ray diffraction data to be dimeric in the solid state. H[Dt-PeP] crystallizes in the centro-symmetric orthorhombic space group, Cmca, with unit cell parameters, a = 17.694(7), b = 11.021(4), and c = 13.073(5) A, and Z = 8, indicating that the molecule must conform to a crystallographic mirror plane or 2-fold axis. A measured density of 1.088 g/cm 3 is in good agreement with a calculated value of 1.074 g/cm 3 for a unit cell volume of 2549.3(A) 3 and a formula weight of 206.25 g. A total of 646 three-dimensional X-ray data were collected on an automated XRD-490 G.E. diffractometer. The structure was solved using a combination of direct methods, Patterson, Fourier, and least-squares refinement techniques. Refinement of the data indicates that H[Dt-PeP] is dimeric, and contains a mirror plane in which the hydrogen-bonded, eight-membered ring lies. A structural disorder involving principally the ethylene carbon but affecting the methyl carbons as well precluded a precise determination of the carbon positions and severely reduced the precision of the final refinement. In the liquid-liquid extraction system consisting of a solution of H[Dt-PeP] in benzene vs an acidic aqueous chloride phase, the extraction of UO 2 2+ follows the stoichiometry: UO 2 sub(A) 2+ + 2(HY) 2 subO = UO 2 (HY 2 ) 2 sub(O) + 2Hsub(A) + where (HY) 2 represents the dimer of H[Dt-PeP] and A and O represent the mutually equilibrated aqueous and organic phases. The expression for the distribution ratio, k, for UO 2 2+ is given. (author)
Plutonium and americium extraction studies with bifunctional organophosphorus extractants
International Nuclear Information System (INIS)
Navratil, J.D.
Neutral bifunctional organophosphorus extractants, such as octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and dihexyl-N,N-diethylcarbamoylmethylphosphonate (CMP), are under study at the Rocky Flats Plant (RFP) to remove plutonium and americium from the 7M nitric acid waste. These compounds extract trivalent actinides from strong nitric acid, a property which distinguishes them from monofunctional organiphosphorus reagents. Furthermore, the reagents extract hydroytic plutonium (IV) polymer which is present in the acid waste stream. The compounds extract trivalent actinides with a 3:1 stoichiometry, whereas tetra- and hexavalent actinides extract with a stoichiometry of 2:1. Preliminary studies indicate that the extracted plutonium polymer complex contains one to two molecules of CMP per plutonium ion and the plutonium(IV) maintains a polymeric structure. Recent studies by Horwitz and co-workers conclude that the CMPO and CMP reagents behave as monodentate ligands. At RFP, three techniques are being tested for using CMP and CMPO to remove plutonium and americium from nitric acid waste streams. The different techniques are liquid-liquid extraction, extraction chromatography, and solid-supported liquid membranes. Recent tests of the last two techniques will be briefly described. In all the experiments, CMP was an 84% pure material from Bray Oil Co. and CMPO was 98% pure from M and T Chemicals
determination of lipophilic extractives in ionic liquid extracts
African Journals Online (AJOL)
Chem. 9: 63-69. Freire CSR, Pinto PCR, Santiago AS,. Silvestre AJD, Evtuquin DV and Neto. CP 2006a Comparative study of lipophilic extractives of hardwoods and corresponding ECF bleached kraft pulps. BioResources. 1: 3-17. Freire CSR, Silvestre AJD and Neto CP. 2005. Lipophilic extractives in. Eucalyptus globulus.
Lab-on-a-Valve Mesofluidic Platform for On-Chip Handling of Carbon-Coated Titanium Dioxide Nanotubes in a Disposable Microsolid Phase-Extraction Mode.
García-Valverde, María Teresa; Rosende, María; Lucena, Rafael; Cárdenas, Soledad; Miró, Manuel
Mesofluidic lab-on-a-valve (LOV) platforms have been proven suitable to accommodate automatic micro-solid-phase extraction (μSPE) approaches with on-chip handling of micrometer-bead materials in a fully disposable mode to prevent sample cross-contamination and pressure-drop effects. The efficiency of the extraction process notably depends upon the sorptive capacity of the material because the sorbent mass is usually down to 10 mg in LOV devices. Nanomaterials, capitalizing upon their enhanced surface-to-volume ratio and diversity of potential chemical moieties, are appealing alternatives to microbead sorbents. However, the handling and confinement of nanomaterials in fluidic chip structures have been challenging to date. This is most likely a consequence of the aggregation tendency of a number of nanomaterials, including carbon-based sorbents, that leads to excessive back-pressure in flowing systems along with irreproducible bead loading. This paper addresses these challenges by ad hoc synthesis of hybrid nanomaterials, such as porous carbon-coated titanium dioxide nanotubes (TiO 2 -NT@pC). Tailoring of the surface polarity of the carbon coating is proven to foster the dispersion of TiO 2 -NT@pC in LOV settings while affording superior extraction capability of moderately nonpolar species from aqueous matrices. The determination of trace-level concentrations of butylparaben (BPB) and triclosan (TCS) in seawater samples is herein selected as a proof-of-concept of the exploitation of disposable nanomaterials in LOV. The mesofluidic platform accommodating μSPE features online hyphenation to liquid chromatography/tandem mass spectrometry (LC/MS/MS) for reliable determination of the target analytes with excellent limits of detection (0.5 and 0.6 ng/L for BPB and TCS, respectively) and intermediate precision (relative standard deviation <5.8%). For 5.0 mL of sample and 200 μL of eluent, enrichment factors of 23 and 14 with absolute extraction efficiencies of 90% ± 14
Nonlocal Intracranial Cavity Extraction
Manjón, José V.; Eskildsen, Simon F.; Coupé, Pierrick; Romero, José E.; Collins, D. Louis; Robles, Montserrat
Automatic and accurate methods to estimate normalized regional brain volumes from MRI data are valuable tools which may help to obtain an objective diagnosis and followup of many neurological diseases. To estimate such regional brain volumes, the intracranial cavity volume (ICV) is often used for normalization. However, the high variability of brain shape and size due to normal intersubject variability, normal changes occurring over the lifespan, and abnormal changes due to disease makes the ICV estimation problem challenging. In this paper, we present a new approach to perform ICV extraction based on the use of a library of prelabeled brain images to capture the large variability of brain shapes. To this end, an improved nonlocal label fusion scheme based on BEaST technique is proposed to increase the accuracy of the ICV estimation. The proposed method is compared with recent state-of-the-art methods and the results demonstrate an improved performance both in terms of accuracy and reproducibility while maintaining a reduced computational burden. PMID:25328511
Nonlocal Intracranial Cavity Extraction
Directory of Open Access Journals (Sweden)
José V. Manjón
Full Text Available Automatic and accurate methods to estimate normalized regional brain volumes from MRI data are valuable tools which may help to obtain an objective diagnosis and followup of many neurological diseases. To estimate such regional brain volumes, the intracranial cavity volume (ICV is often used for normalization. However, the high variability of brain shape and size due to normal intersubject variability, normal changes occurring over the lifespan, and abnormal changes due to disease makes the ICV estimation problem challenging. In this paper, we present a new approach to perform ICV extraction based on the use of a library of prelabeled brain images to capture the large variability of brain shapes. To this end, an improved nonlocal label fusion scheme based on BEaST technique is proposed to increase the accuracy of the ICV estimation. The proposed method is compared with recent state-of-the-art methods and the results demonstrate an improved performance both in terms of accuracy and reproducibility while maintaining a reduced computational burden.
Study on the extraction kinetics of U(IV) extraction with neutral phosphoric extractant
International Nuclear Information System (INIS)
Lin Zhou; Liao Shishu; Li Zhou
The extraction kinetics of U(IV) in the diisooctyl isobutylphosphonate system has been studied by using the single drop method. The effects of the concentrations of U(IV), HCl and extractant on the extraction rate have been examined. In a certain HCl concentration, the extraction rate equation has been acquired and in the condition of various HCl concentration the extraction rate of U(IV) is proportional to [HCl 1.51 . The effect of operation temperature was also examined, and the calculated apparent activation energy is equal to 23.24 kJ/mol. From the experimental results, the extraction reaction process and the rate-controlling step have been deduced. (4 figs., 5 tabs.)
Effect of soybean extract after tooth extraction on osteoblast numbers
Directory of Open Access Journals (Sweden)
Rosa Sharon Suhono
Full Text Available Background: Many researches were done to find natural materials that may increase and promote bone healing processes after trauma and surgery. One of natural material that had been studied was soybean extract which contains phytoestrogen, a non-steroidal compounds found in plants that may binds to estrogen receptors and have estrogen-like activity. Purpose: The aim of this study was to investigate the effect of soybean extract feeding on the number of osteoblast cells in alveolar bone socket after mandibular tooth extraction. Methods: This study was studied on male Rattus norvegicus strain Wistar. Seventeen rats divided into three groups were used in this study. Group 1 fed with carboxy methyl cellulose (CMC solution 0,2% for seven days, and the left mandibular central incisivus was extracted; group 2 fed with soybean extract for seven days and the left mandibular central incisives was extracted; group 3 received the left mandibular central incisives extraction followed by soybean extract feeding for seven days after the extraction. All groups were sacrificed on the seventh day post-extraction, and the alveolar bone sockets were taken for histopathological observation. The tissues were processed and stained using hematoxylin and eosin to identify the amount of osteoblast cells. The number of osteoblast cells was counted using an Image Tool program. The data was analyzed statistically using the One-Way ANOVA test. Results: Significant differences were found on the number of osteoblast cells in alveolar bone after tooth extraction between groups. Group 2 (fed with soybean extract is higher than group 1 (fed with CMC and group 3 (fed with soybean extract after extraction. Conclusion: Soybean extract feeding that given for seven days pre-tooth extraction can increase the number of osteoblast cells compared with the group that were not given soybean extract feeding and also with the group that were given soybean extract feeding for seven days post
CERN PhotoLab
A pair of prototype septum magnets for the extraction systems of the SPS. Each of the two extraction systems will contain eighteen of these septum magnets (eight with a 4 mm septum and ten with a 16 mm septum) mounted in pairs in nine vacuum tanks.
[Endoscopic extraction of gallbladder calculi].
Kühner, W; Frimberger, E; Ottenjann, R
Endoscopic extraction of gallbladder stones were performed, as far as we know for the first time, in three patients with combined choledochocystolithiasis. Following endoscopic papillotomy (EPT) and subsequent mechanical lithotripsy of multiple choledochal concrements measuring up to 3 cm the gallbladder stones were successfully extracted with a Dormia basket through the cystic duct. The patients have remained free of complications after the endoscopic intervention.
Extractive separation of tellurium(4)
International Nuclear Information System (INIS)
Gawali, S.B.; Shinde, V.M.
A method is described for the extraction of tellurium (4) from hydrobromic acid media using 4-methyl-2-pentanol as an extractant. The method affords the determination of tellurium after its separation from Se, Au, Cu, Pb, Fe, Os, V and Al. (author)
Solids recycling in solvent extraction
International Nuclear Information System (INIS)
Robinson, L.F.
In an extraction process for extracting values from a first stream into a substantially immiscible second stream using a multi-compartmental rotary contactor, unwanted solids formed in the contactor and discharged at least partly with the the first stream are separated and re-entered into the contactor intermediate the points at which the streams are discharged. (author)
Parallel artificial liquid membrane extraction
DEFF Research Database (Denmark)
Gjelstad, Astrid; Rasmussen, Knut Einar; Parmer, Marthe Petrine
This paper reports development of a new approach towards analytical liquid-liquid-liquid membrane extraction termed parallel artificial liquid membrane extraction. A donor plate and acceptor plate create a sandwich, in which each sample (human plasma) and acceptor solution is separated by an arti......This paper reports development of a new approach towards analytical liquid-liquid-liquid membrane extraction termed parallel artificial liquid membrane extraction. A donor plate and acceptor plate create a sandwich, in which each sample (human plasma) and acceptor solution is separated...... by an artificial liquid membrane. Parallel artificial liquid membrane extraction is a modification of hollow-fiber liquid-phase microextraction, where the hollow fibers are replaced by flat membranes in a 96-well plate format....
Uranium extraction from phosphoric acid
International Nuclear Information System (INIS)
Lounis, A.
A study has been carried out for the extraction of uranium from phosphoric acid produced in Algeria. First of all, the Algerian phosphoric acid produced in Algeria by SONATRACH has been characterised. This study helped us to synthesize a phosphoric acid that enabled us to pass from laboratory tests to pilot scale tests. We have then examined extraction and stripping parameters: diluent, DZEPHA/TOPO ratio and oxidising agent. The laboratory experiments enabled us to set the optimum condition for the choice of diluent, extractant concentration, ratio of the synergic mixture, oxidant concentration, redox potential. The equilibrium isotherms lead to the determination of the number of theoretical stages for the uranium extraction and stripping of uranium, then the extraction from phosphoric acid has been verified on a pilot scale (using a mixer-settler)
Improving IUE High Dispersion Extraction
Lawton, Patricia J.; VanSteenberg, M. E.; Massa, D.
We present a different method to extract high dispersion International Ultraviolet Explorer (IUE) spectra from the New Spectral Image Processing System (NEWSIPS) geometrically and photometrically corrected (SI HI) images of the echellogram. The new algorithm corrects many of the deficiencies that exist in the NEWSIPS high dispersion (SIHI) spectra . Specifically, it does a much better job of accounting for the overlap of the higher echelle orders, it eliminates a significant time dependency in the extracted spectra (which can be traced to the background model used in the NEWSIPS extractions), and it can extract spectra from echellogram images that are more highly distorted than the NEWSIPS extraction routines can handle. Together, these improvements yield a set of IUE high dispersion spectra whose scientific integrity is sign ificantly better than the NEWSIPS products. This work has been supported by NASA ADP grants.
Selectivity in extraction of copper and indium with chelate extractants
International Nuclear Information System (INIS)
Zivkovic, D.
Simultaneous extraction of copper and indium with chelate extractants (LIX84 and D2E11PA) was described. Stechiometry of metal-organic complexes examined using the method of equimolar ratios resulted in CuR 2 and InR 3 forms of hydrophobic extracting species. A linear correlation was obtained between logarithm of distribution coefficients and chelate agents and pH, respectively. Selectivity is generally higher with higher concentrations of chelate agents in the organic phase, and is decreased with increase of concentration of hydrogen ions in feeding phase. (Original)
Selective extraction of natural bitumen
International Nuclear Information System (INIS)
Starshov, M.; Starshov, I.
The work performed in the field of natural bitumen extraction is aimed at maximum separation of organic phase. On treating bituminous rocks with solvents, the associated metals are extracted together with the organic phase and may further exert a negative effect on refining of natural bitumen. the authors propose a simplified two stage technique for the extraction of bitumen which enables to utilize V and Ni contained in the concentrate of the second stage extraction (Table). At the first stage, negative bitumen is extracted with the summary content of metals not exceeding 0.005%. This allows to avoid de metallization of native bitumen and subject it to treatment by catalytic cracking. during this stage gasoline and kerosene fractions, different oil distillates and condensates can be used as solvents. at the second stage, aromatic and halo id compounds bearing wastes and by-products, i.e. cheap and non deficient reagents, serve as solvents. The technology was tested under laboratory conditions using Tatar bituminous sands. It is also possible to use one solvent only, however, on condition that at first the oil product with the summary metal content below 0.005%, and then the remaining product is extracted. The proposed technology has proved so universal that it can be applied to refining any type of raw material to be found in the territory of the Tatar republic, using surface extraction complexes. (author). 9 refs., tab
Mineral extraction and transport device
Energy Technology Data Exchange (ETDEWEB)
Plaga, K.
A device for the extraction and transport of stratified mineral deposits notably coal, having a transport run with lengths of transport troughing, an extraction run with lengths of extraction troughing, and a power-driven traction chain guided round return devices and carrying extraction bodies together with optional transport units. The transport and extraction troughing have guide members on which the extraction bodies and the transport units are guided with the aid of guide formations. Each extraction body consists of a headpiece having two laterally protruding guide formations, and an endpiece having two laterally protruding guide formations and a centrepiece. The headpiece and the endpiece are swivellably linked to the centrepiece through an axis running substantially at right angles to the traction axis of the traction chain and substantially at right angles to the floor of the lengths of transport troughing in the transport run. The centrepiece has an additional articulation about an axis substantially orthogonal to the swivel axis of the headpiece and the endpiece. Guide members are additionally provided in the vicinity of the return devices whereby the guide formations on each headpiece and endpiece receive continued guidance.
Selective solvent extraction of oils
Energy Technology Data Exchange (ETDEWEB)
In the selective solvent extraction of naphthenic base oils, the solvent used consists of the extract obtained by treating a paraffinic base oil with a selective solvent. The extract, or partially spent solvent is less selective than the solvent itself. Selective solvents specified for the extraction of the paraffinic base oil are phenol, sulphur dioxide, cresylic acid, nitrobenzene, B:B/sup 1/-dichlorethyl ether, furfural, nitroaniline and benzaldehyde. Oils treated are Coastal lubricating oils, or naphthenic oils from the cracking, or destructive hydrogenation of coal, tar, lignite, peat, shale, bitumen, or petroleum. The extraction may be effected by a batch or counter-current method, and in the presence of (1) liquefied propane, or butane, or naphtha, or (2) agents which modify the solvent power such as, water, ammonia, acetonitrile, glycerine, glycol, caustic soda or potash. Treatment (2) may form a post-treatment effected on the extract phase. In counter-current treatment in a tower some pure selective solvent may be introduced near the raffinate outlet to wash out any extract therefrom.
Extraction of uranium with emulsion membrane process use tributylphosphate extractant
International Nuclear Information System (INIS)
Basuki, K.T.; Sudibyo, R.; Bambang EHB; Muhadi, A.W.
To increase the effectiveness of extraction process with so for to occur, it was tried the extraction with a couple of extraction and stripping process. This couple process was called liquid membrane emulsion. As membrane was used mix surfactant (Span-80), tributylphosphate in kerosene, natrium carbonate, while as a feeder was uranium solution with 500 concentration ppm in 0.5 - 3 M nitrate acid. In this experiment the variable investigated were % surfactant (1 - 5 %), rotary speed for membrane making (2,500 - 10.000 rpm). The optimal condition result of experiment were 5 % surfactant, 3 M nitrate acid, rotary speed 10.000 rpm and (Kd eksU ) 57 %, and (Kd strippU ) 87 %, Kd eksU at liquid-liquid extraction is 44 %. (author)
Actinides complexes in solvent extraction. The amide type of extractants
International Nuclear Information System (INIS)
Musikas, C.; Condamines, N.; Charbonnel, M.C.; Hubert, H.
The N,N-dialkylamides and the N,N'-tetraalkyl. 2-alkyl 1,3-diamide propane are two promising classes of extractants which could replace advantageously the organophosphorus molecules for the separations of the actinide. The main advantages of the amides lie in their complete incinerability and the small interference of their radiolytic and hydrolytic degradation products for the processes. The actinide extraction chemistry with various amides is reviewed in this paper
Adult orthodontic therapy: extraction versus non-extraction.
Baumrind, S
This study addresses the problem of randomization of subjects with respect to an irreversible aspect of treatment strategy, namely, the extraction of teeth. The investigation includes both prospective and retrospective components. The data presented focus on clinician decision-making. Of the 1321 potential subjects for whom records were taken, 250 met the inclusion criteria. Of these subjects, 82 declined to participate and 20 were dropped because of difficulty in obtaining five independent evaluations of their records within a reasonable time frame. Thus, the final sample contained 148 subjects. Approximately one-third of the subjects in the sample are adult, somewhat more than half are female, and Class I malocclusions outnumber Class II malocclusions by a count of 95 to 53. Patterns of agreement and disagreement among five clinicians include: a) agreement/disagreement on the primary decision whether or not to extract: the data reveal a strong tendency towards consensus among the clinicians; b) agreement/disagreement on extraction pattern in patients in whom the clinician believes that extraction is indicated: the clinicians tended strongly to agree on extraction pattern; c) agreement/disagreement on the need for adjunctive orthognathic surgery: decisions favoring surgery were more common and more 'definite' than 'probable' in the adult cohort than in the adolescent cohort but this tendency was not as strong as had been anticipated; d) agreement/disagreement concerning Angle classification: disagreements were more common than had been anticipated; and e) differences among the individual clinicians as to their ratios of extraction/non-extraction decisions: overall, clinicians opted for extraction less frequently in the adolescent cohort than in the adult cohort (55 vs. 66%). Because the data are drawn from actual clinical experience, the conclusions involve a number of assumptions and their generalizability should be evaluated.
Mechano sorptive behaviour of notched beams in bending
DEFF Research Database (Denmark)
Jensen, Signe Kamp; Hoffmeyer, Preben
Short term bending tests with end-notched beams at constant or varying moisture content have shown an apparent contradictory dependency between moisture content and strength. The higher the moisture content the higher the strength. Varying moisture results in particularly significant differences...... and by neglecting deformation due to shear. Compression stresses perpendicular to grain in excess of 6 MPa were found in the vicinity of the notch following a period of adsorption. Similarly, small tension stresses of the order 1 MPa were registered in this area when the specimens were at their most dry condition...
Reductive and sorptive properties of sulfate green rust (GRSO4)
DEFF Research Database (Denmark)
Nedel, Sorin
The Fe(II), Fe(III) hydroxide containing sulfate in its structure, called sulfate green rust (GRSO4), can effectively reduce and convert contaminants to less mobile and less toxic forms. However, the ability of GRSO4 to remove positively charged species from solution, via sorption, is very limited...
Novel Fluorinated Tensioactive Extractant Combined with Flotation for Decontamination of Extractant Residual during Solvent Extraction
Wu, Xue; Chang, Zhidong; Liu, Yao; Choe, Chol Ryong
Solvent-extraction is widely used in chemical industry. Due to the amphiphilic character, a large amount of extractant remains in water phase, which causes not only loss of reagent, but also secondary contamination in water phase. Novel fluorinated extractants with ultra-low solubility in water were regarded as effective choice to reduce extractant loss in aqueous phase. However, trace amount of extractant still remained in water. Based on the high tensioactive aptitude of fluorinated solvent, flotation was applied to separate fluorinated extractant remaining in raffinate. According to the data of surface tension measurement, the surface tension of solution was obviously decreased with the addition of fluorinated extractant tris(2,2,3,3,4,4,5,5-octafluoropentyl) phosphate (FTAP). After flotation, the FTAP dissolved in water can be removed as much as 70%, which proved the feasibility of this key idea. The effects of operation time, gas velocity, pH and salinity of bulk solution on flotation performance were discussed. The optimum operating parameters were determined as gas velocity of 12ml/min, operating time of 15min, pH of 8.7, and NaCl volume concentration of 1.5%, respectively. Moreover, adsorption process of FTAP on bubble surface was simulated by ANSYS VOF model using SIMPLE algorithm. The dynamic mechanism of flotation was also theoretically investigated, which can be considered as supplement to the experimental results.
TSCA Inventory Data Extraction Tool
U.S. Environmental Protection Agency — This data extraction tool contains the non confidential identities of chemical substances submitted under the Toxic Substances Control Act (TSCA). TSCA was enacted...
Combined keratoplasty and cataract extraction.
Demeler, U; Hinzpeter, E N
A short film showing our technique of combined penetrating keratoplasty and intracapsular cataract extraction was shown, and the postoperative results in 72 eyes after an average of 3 years were reported.
Extractive spectrophotometric determination of thorium
International Nuclear Information System (INIS)
Venkatesan, M.; Gopalakrishnan, V.; Ramanujam, A.; Nadkarni, M.N.
An extractive spectrophotometric method has been standardized for the analysis of 0.2 to 1.6 milligrams of thorium present in nitric acid solutions. The method involves the extraction of thorium from nitric acid solutions into 0.5 M thenoyl trifluoro acetone (HTTA) in benzene and its direct estimation from the organic extract by spectrophotometry as Thoron colour complex. In this method, interference due to iron upto 5 milligrams can be suppressed by adding ascorbic acid in the ratio of 1:2 prior to HTTA extraction. Uranium(VI) does not interefere even when present in 2000 times the amount of thorium. Plutonium and cerium do not interfere at one milligram level whereas zirconium interferes in this method. The overall error variation and precision of this method has been determined to be +- 3.5%. (author)
Extraction chromatography of fission products
International Nuclear Information System (INIS)
Bonnevie-Svendsen, M.; Goon, K.
Various cases of using extraction chromatography during analysis of fission products are reviewed. The use of the extraction chromatography method is considered while analysing reprocessed products of nuclear fuel for quantitative radiochemical analysis and control of fission product and actinoide separation during extraction and their chemical state in production solutions. The method is used to obtain pure fractions of typical burnup monitors (neodymium, molybdenum, cerium, cesium, europium, lanthanides) during determination of nuclear fuel burnup degree. While studying the nature of nuclear reactions the method is used to separate quickly short-life isotopes, to purify β-radiator fractions before measuring their half-life periods, to enrich isotopes forming with low output during fission. Examples of using extraction chromatography are given to separate long half-life or stable fission products from spent solutions, to control environment object contamination
Coil for LEAR extraction septum
CERN PhotoLab
Which way does the current flow ? This intriguing object is the coil for the LEAR extraction septum. There were two septa, first a thin one, then this one, not so thin, somewhat on the borderline between septum and bending magnet.
Scenario Customization for Information Extraction
National Research Council Canada - National Science Library
Yangarber, Roman
Information Extraction (IE) is an emerging NLP technology, whose function is to process unstructured, natural language text, to locate specific pieces of information, or facts, in the text, and to use these facts to fill a database...
VT Mineral Resources - MRDS Extract
Vermont Center for Geographic Information — (Link to Metadata) MRDSVT is an extract from the Mineral Resources Data System (MRDS) covering the State of Vermont only. MRDS database contains the records provided...
Process for extracting oil shale
Energy Technology Data Exchange (ETDEWEB)
A process is described for recovering bituminous material from oil shale, characterized in that the oil shale is extracted with wood spirits oil (byproduct of woodspirit rectification), if necessary in admixture with other solvents in the cold or the hot.
aqueous root extract on spermatogenesis
African Journals Online (AJOL)
Four groups were gavaged with the whole plant or root aqueous extract in low or high doses. The male ... motility and morphology as well as chromatin integrity were evaluated. Results: Serum ... Treatment of disease began long ago with the.
Bio technologies in extractive metallurgy
International Nuclear Information System (INIS)
Morin, D.
The bio technologies processes used (or used in the future) in extractive metallurgy are presented. The most advanced one is the degradation of the metals sulfides (bacteria catalyzing the sulfides oxidation of Au, Cu, U). Two other applications outside the extractive metallurgy are also described: metals fixation by living or dead organic matter and the biological destruction of organic reactants such as cyanides. (A.B.)
Advanced integrated solvent extraction systems
Energy Technology Data Exchange (ETDEWEB)
Horwitz, E.P.; Dietz, M.L.; Leonard, R.A. [Argonne National Lab., IL (United States)
Advanced integrated solvent extraction systems are a series of novel solvent extraction (SX) processes that will remove and recover all of the major radioisotopes from acidic-dissolved sludge or other acidic high-level wastes. The major focus of this effort during the last 2 years has been the development of a combined cesium-strontium extraction/recovery process, the Combined CSEX-SREX Process. The Combined CSEX-SREX Process relies on a mixture of a strontium-selective macrocyclic polyether and a novel cesium-selective extractant based on dibenzo 18-crown-6. The process offers several potential advantages over possible alternatives in a chemical processing scheme for high-level waste treatment. First, if the process is applied as the first step in chemical pretreatment, the radiation level for all subsequent processing steps (e.g., transuranic extraction/recovery, or TRUEX) will be significantly reduced. Thus, less costly shielding would be required. The second advantage of the Combined CSEX-SREX Process is that the recovered Cs-Sr fraction is non-transuranic, and therefore will decay to low-level waste after only a few hundred years. Finally, combining individual processes into a single process will reduce the amount of equipment required to pretreat the waste and therefore reduce the size and cost of the waste processing facility. In an ongoing collaboration with Lockheed Martin Idaho Technology Company (LMITCO), the authors have successfully tested various segments of the Advanced Integrated Solvent Extraction Systems. Eichrom Industries, Inc. (Darien, IL) synthesizes and markets the Sr extractant and can supply the Cs extractant on a limited basis. Plans are under way to perform a test of the Combined CSEX-SREX Process with real waste at LMITCO in the near future.
Uranium refining by solvent extraction
International Nuclear Information System (INIS)
Kraikaew, J.; Srinuttrakul, W.
The solvent extraction process to produce higher purity uranium from yellowcake was studied in laboratory scale. Yellowcake, which the uranium purity is around 70% and the main impurity is thorium, was obtained from monazite processing pilot plant of Rare Earth Research and Development Center in Thailand. For uranium re-extraction process, the extractant chosen was Tributylphosphate (TBP) in kerosene. It was found that the optimum concentration of TBP was 10% in kerosene and the optimum nitric acid concentration in uranyl nitrate feed solution was 4 N. An increase in concentrations of uranium and thorium in feed solution resulted in a decrease in the distribution of both components in the extractant. However, the distribution of uranium into the extractant was found to be more than that of thorium. The equilibration study of the extraction system, UO_2(NO_3)/4N HNO_3 – 10%TBP/Kerosene, was also investigated. Two extraction stages were calculated graphically from 100,000 ppm uranium concentration in feed solution input with 90% extraction efficiency and the flow ratio of aqueous phase to organic phase was adjusted to 1.0. For thorium impurity scrubbing process, 10% TBP in kerosene was loaded with uranium and minor thorium from uranyl nitrate solution prepared from yellowcake and was scrubbed with different low concentration nitric acid. The results showed that at nitric acid normality was lower than 1 N, uranium distributed well to aqueous phase. As conclusion, optimum nitric acid concentration for scrubbing process should not less than 1 N and diluted nitric acid or de-ionized water should be applied to strip uranium from organic phase in the final refining process. (author)
Extracting useful information from images
DEFF Research Database (Denmark)
Kucheryavskiy, Sergey
The paper presents an overview of methods for extracting useful information from digital images. It covers various approaches that utilized different properties of images, like intensity distribution, spatial frequencies content and several others. A few case studies including isotropic and heter......The paper presents an overview of methods for extracting useful information from digital images. It covers various approaches that utilized different properties of images, like intensity distribution, spatial frequencies content and several others. A few case studies including isotropic...
Extractive Summarisation of Medical Documents
Abeed Sarker; Diego Molla; Cecile Paris
Background Evidence Based Medicine (EBM) practice requires practitioners to extract evidence from published medical research when answering clinical queries. Due to the time-consuming nature of this practice, there is a strong motivation for systems that can automatically summarise medical documents and help practitioners find relevant information. Aim The aim of this work is to propose an automatic query-focused, extractive summarisation approach that selects informative sentences from medic...
Phoenix I energy extraction experiment
International Nuclear Information System (INIS)
Hoffman, J.M.; Patterson, E.L.; Tisone, G.C.; Moreno, J.B.
Energy extraction experiments are reported for the Phoenix I amplifier driven by a discharge-initiated oscillator-preamplifier system operating on mixtures of either SF 6 -HI or SF 6 -C 2 H 6 and an electron-beam-initiated intermediate amplifer (lambda-3) fueled with H 2 and F 2 mixtures. When the oscillator-preamplifier system operated with mixtures of SF 6 -HI the input spectrum to the Phoenix I amplifier contained approx. 28 P-branch vibrational-rotational lines which were almost identical to the input spectrum from the H 2 -F 2 fueled oscillator. In this case the energy extraction measurements were essentially the same as the results obtained with the spectrum produced using H 2 and F 2 mixtures. For an input intensity of 10 7 W/cm 2 , 170 J were extracted from the amplifier. With the SF 6 -C 2 H 6 spectrum, extraction was only obtained from the first three excited vibrational levels. This result indicates that most of the energy in the amplifier could be extracted on the first three excited vibrational levels. It is shown that the extraction results can be fit with a simple two level model. The radius of curvature of the beam was estimated using a lateral shearing interferometer. It was found that the Phoenix I amplifier altered the radius of curvature
Evaporative and sorptive cooling. Possibilities and limitations in air treatment.; Evaporativ och sorptiv kylning. Moejligheter och begraensningar vid luftbehandling
Energy Technology Data Exchange (ETDEWEB)
Lindholm, T. [Chalmers Univ. of Techn., Goeteborg (Sweden). Dept. of Building Services Engineering
A primary demand for a good indoor climate in a building is that temperature and humidity are maintained at comfortable levels, regardless of the prevailing outdoor climate. Some buildings often have a heat surplus for a great part of the year due to internal activities, even in climates with moderate ambient temperatures. This heat surplus has to be removed in order to fulfil the specified requirements on the indoor climate. The focus in this report is on possibilities and limitations using evaporative and desiccant cooling to satisfy the cooling demands in such buildings. Today the most common technical solution is to use a compressor refrigeration system for air-conditioning. As a result of the greenhouse effect and the ozone depletion debate, the prerequisites for compressor refrigeration systems have been changed. Evaporative cooling is an interesting alternative to conventional compressor refrigeration systems. However, the use of evaporative cooling presupposes all-air systems. The use of such a system will also, to a large extent, be limited by ambient conditions as well as the settled demands on the indoor climate. High outdoor humidity levels have great influence on the supply-air temperature achievable, i.e., cooling loads possible to meet. One way to considerably reduce the influence of these limitations is to use desiccant cooling, i.e., to dehumidify the ambient air before the evaporative stages. In this report, a general methodology to describe possibilities and limitations for evaporative and desiccant cooling, is presented. The major advantage of this methodology is that it may give rise to an increased understanding of these processes and, hence, be a guide to a proper dimensioning.
The method for simultaneous extraction and back extraction in liquid three-phase system and equipment for simultaneous extraction and back extraction in liquid three-phase system
International Nuclear Information System (INIS)
Palyska, W.; Chmielewski, A.G.
The method for simultaneous extraction and back extraction in liquid three-phase system has been worked out. The equipment designed for that process has been also subject of the patent. The interesting component is extracted first to intermediate phase consists of magnetic solvent keeping two extracting phases separately. The intermediate magnetic liquid has been kept in its position using a stable magnet maintained on the surface of the extraction vessel. Then the component pass from intermediate phase to the third phase as a result of back extraction. Mixing in the extraction and back extraction zones is organized by means of rotating shaft going along the whole apparatus. The extraction and back extraction processes occur simultaneously as a result of continuous flow of solvent in their zones. The single extraction back extraction facilities can be joined in larger batteries. 3 figs
Extraction and characterization of galactomannan extracted from Prosopis juliflora seeds
International Nuclear Information System (INIS)
Rodrigues, Delane da C.; Cunha, Arcelina P.; Oliveira, Williara Q. de; Gallao, Maria Izabel; Azeredo, Henriette M. C de
Different seeds are rich in polysaccharides, which are widely used in research and in industry. The objective was to extract galactomannan from mesquite seeds (Prosopis juliflora) and evaluate their chemical properties for future application in edible films. To test the feasibility of using the polysaccharide, the yield was obtained and the material analyzed by Thermal Analysis (TGA-Thermogravimetric Analysis and Calorimetry Differential Scanning-DSC), Spectroscopy Infrared Region Fourier Transform (FTIR) and Nuclear Magnetic Resonance (NMR). According to the results, the galactomannan was equivalent with the polysaccharides extracted from other sources except for the low yield (6.6%). (author)
NMR investigation of coal extracts
Energy Technology Data Exchange (ETDEWEB)
Lang, I; Sebor, G [Ceskoslovenska Akademie Ved, Prague. Hornicky Ustav; Sebor, G Jr; Hajek, M; Mostecky, J [Vysoka Skola Chemicko-Technologicka, Prague (Czechoslovakia)
Proton NMR spectroscopy was used for the evaluation of 10% coal extract solutions in deuterated pyridine. Four types of Czechoslovak coal were analyzed. Agreement was found between the aromaticity of coal extracts calculated from /sup 1/H NMR data using Brown's method and Ladner's and Williams' method and the characterization of an average molecule of the coal extract by the number of non-bridge carbon atoms of aromatic rings, by the overall number of aromatic ring carbon atoms and the number of aromatic rings, determined by the Williams and Ferris methods. The methods for calculating carbon distribution from /sup 1/H NMR data, however, contain some constants theoretically estimated or experimentally found using the method which still remain to be verified.
Indium recovery by solvent extraction
International Nuclear Information System (INIS)
Fortes, Marilia Camargos Botelho
Indium has been recovered as a byproduct from residues generated from the sulfuric acid leaching circuits in mineral plants for zinc recovery. Once its recovery comes from the slags of other metals recovery, it is necessary to separate it from the other elements which usually are present in high concentrations. Many works have been approaching this separation and indicate the solvent extraction process as the main technique used. In Brazilian case, indium recovery depends on the knowledge of this technique and its development. This paper describes the solvent extraction knowledge for the indium recovery from aqueous solutions generated in mineral plants. The results for determination of the best experimental conditions to obtain a high indium concentration solution and minimum iron poisoning by solvent extraction with di (2-ethylhexyl)-phosphoric acid (D2EHPA) solubilized in isoparafin and exxsol has been presented. (author)
Salt effects in electromembrane extraction
DEFF Research Database (Denmark)
Seip, Knut Fredrik; Jensen, Henrik; Kieu, Thanh Elisabeth
Electromembrane extraction (EME) was performed on samples containing substantial amounts of NaCl to investigate how the presence of salts affected the recovery, repeatability, and membrane current in the extraction system. A group of 17 non-polar basic drugs with various physical chemical...... this loss and the physical chemical properties of these substances was seen. The recovery loss was hypothesized to be caused by ion pairing in the SLM, and a mathematical model for the extraction recovery in the presence of salts was made according to the experimental observations. Some variations...... to the EME system reduced this recovery loss, such as changing the SLM solvent from NPOE to 6-undecanone, or by using a different EME setup with more favorable volume ratios. This was in line with the ion pairing hypothesis and the mathematical model. This thorough investigation of how salts affect EME...
Solvent extraction: the coordination chemistry behind extractive metallurgy.
Wilson, A Matthew; Bailey, Phillip J; Tasker, Peter A; Turkington, Jennifer R; Grant, Richard A; Love, Jason B
The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, M(n+), metalate anions, MXx(n-), or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal cations or metal salts into a water-immiscible solvent usually operate in the inner coordination sphere of the metal and provide donor atom types or dispositions which favour the formation of particularly stable neutral complexes that have high solubility in the hydrocarbons commonly used in recovery processes. In the extraction of metalates, the structures of the neutral assemblies formed in the water-immiscible phase are usually not well defined and the cationic reagents can be assumed to operate in the outer coordination spheres. The formation of secondary bonds in the outer sphere using, for example, electrostatic or H-bonding interactions are favoured by the low polarity of the water-immiscible solvents.
Ocean Thermal Extractable Energy Visualization
Energy Technology Data Exchange (ETDEWEB)
Ascari, Matthew [Lockheed Martin Corporation, Bethesda, MD (United States)
The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world's ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today's state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.
Photochemical separation and extraction device
International Nuclear Information System (INIS)
Wada, Yukio; Morimoto, Kyoichi.
The present invention concerns a device for separating neptunium and plutonium from highly radioactive liquid wastes, in which valance control by irradiation of UV rays and extraction operation by using an organic solvent can be conducted simultaneously in the same reaction vessel. Namely, a step of irradiating UV rays to the liquid in the reaction vessel to control the valence of predetermined materials and a step of separating the materials by conducting solvent-extraction while stirring with a solvent are conducted simultaneously or successively. Then, facilities for the separation method can be reduced and the operation steps can be simplified. (N.H.)
11. Russian Conference on Extraction. Abstracts
International Nuclear Information System (INIS)
Zolotov, Yu.A.
Results of fundamental and applied investigations in the region of chemistry of extraction, technology and analytical chemistry are presented. Modern state of theoretical and experimental investigations in the region of thermodynamics and kinetics of extraction by organic phosphorus compounds, organic nitrogen compounds and their mixtures are described. Date on mass exchange, extraction process simulation, extraction apparatuses are given
Extraction of copper zinc and iron from hydrochloric acid solutions by means of different extractants
Energy Technology Data Exchange (ETDEWEB)
Zhivkova, Svetlana [Institute of Chemical Engineering - Bulgarian Academy of Sciences, Sofia (Bulgaria)
The extraction of copper, zinc and iron from hydrochloric acid solutions has been studied. The experiments have been carried out using various solvents, involving different extraction mechanisms – solvating, anion-exchange, cation-exchange, bifunctional . Mixtures of these extractants have been also used. The extraction properties of these extractant mixtures toward copper, zinc and iron, the effect of used modifiers and diluents have been also investigated. Key words: Copper, Zinc, Iron, Extraction, Extractant, Modifier, Diluent.
Noble metal extraction and sorption concentrating
International Nuclear Information System (INIS)
Petrukhin, O.M.; Malofeeva, G.I.
Works performed in the USSR Academy of Sciences GEOCHI laboratory of extraction methods and devoted to selectivity problems of extraction and sorption methods of platinum metal, cadmium and indium concentrating in analytical chemistry are discussed. On choosing complexino. reagent main attention is paid to the selectivity variation based on different stability of metal complexes. Platinum metals are extracted in the form of ion associates when usinq hard, mainly oxyqen-containing, extractants. Coordination-solvated metal complexes are extracted white usinq extractants containing sulfur, trivalent phosphorus and aromatic nitroqen as donor anions. Selectivity is maximum for sulfur- and nitroren-containinq extractants and sorbents. In case of the group extraction of platinum metals sorption is preferable and in case of selective extraction of individual metals, especially, in case of need of relative concentratinq extraction is preferable
Uranium extraction from underground deposits
International Nuclear Information System (INIS)
Wolfe, C.R.
Uranium is extracted from underground deposits by passing an aqueous oxidizing solution of carbon dioxide over the ore in the presence of calcium ions. Complex uranium carbonate or bicarbonate ions are formed which enter the solution. The solution is forced to the surface and the uranium removed from it
Feature extraction using fractal codes
B.A.M. Ben Schouten; Paul M. de Zeeuw
Fast and successful searching for an object in a multimedia database is a highly desirable functionality. Several approaches to content based retrieval for multimedia databases can be found in the literature [9,10,12,14,17]. The approach we consider is feature extraction. A feature can be seen as a
Feature Extraction Using Fractal Codes
B.A.M. Schouten (Ben); P.M. de Zeeuw (Paul)
htmlabstractFast and successful searching for an object in a multimedia database is a highly desirable functionality. Several approaches to content based retrieval for multimedia databases can be found in the literature [9,10,12,14,17]. The approach we consider is feature extraction. A feature can
Extraction of Proteins with ABS
Desai, R.K.; Streefland, M.; Wijffels, R.H.; Eppink, M.H.M.
Over the past years, there has been an increasing trend in research on the extraction and purification of proteins using aqueous biphasic systems (ABS) formed by polymers, e.g., polyethylene glycol (PEG). In general, when dealing with protein purification processes, it is essential to maintain their
Extractive Summarisation of Medical Documents
Directory of Open Access Journals (Sweden)
Abeed Sarker
Full Text Available Background Evidence Based Medicine (EBM practice requires practitioners to extract evidence from published medical research when answering clinical queries. Due to the time-consuming nature of this practice, there is a strong motivation for systems that can automatically summarise medical documents and help practitioners find relevant information. Aim The aim of this work is to propose an automatic query-focused, extractive summarisation approach that selects informative sentences from medical documents. MethodWe use a corpus that is specifically designed for summarisation in the EBM domain. We use approximately half the corpus for deriving important statistics associated with the best possible extractive summaries. We take into account factors such as sentence position, length, sentence content, and the type of the query posed. Using the statistics from the first set, we evaluate our approach on a separate set. Evaluation of the qualities of the generated summaries is performed automatically using ROUGE, which is a popular tool for evaluating automatic summaries. Results Our summarisation approach outperforms all baselines (best baseline score: 0.1594; our score 0.1653. Further improvements are achieved when query types are taken into account. Conclusion The quality of extractive summarisation in the medical domain can be significantly improved by incorporating domain knowledge and statistics derived from a specialised corpus. Such techniques can therefore be applied for content selection in end-to-end summarisation systems.
DNA Extraction and Primer Selection
DEFF Research Database (Denmark)
Karst, Søren Michael; Nielsen, Per Halkjær; Albertsen, Mads
Talk regarding pitfalls in DNA extraction and 16S amplicon primer choice when performing community analysis of complex microbial communities. The talk was a part of Workshop 2 "Principles, Potential, and Limitations of Novel Molecular Methods in Water Engineering; from Amplicon Sequencing to -omics...
Butterfly extracts show antibacterial activity
Extracts of several British butterfly species were tested and shown to possess powerful bactericidal activity against the gram-positive bacteria Staphylococcus aureus (S. aureus). The active compounds were identified as hydroxylated pyrrolizidine alkaloids (PAs) related to loline with nitrogen at C-...
Development of new natural extracts.
Lavoine-Hanneguelle, Sophie; Périchet, Christine; Schnaebele, Nicolas; Humbert, Marina
For over the past 20 years, a remarkable development in the study and search of natural products has been observed. This is linked to a new market trend towards ecology and also due to new regulations. This could be a rupture, but also a real booster for creativity. Usually, in the flavor and fragrance field, creativity was boosted by the arrival of new synthetic molecules. Naturals remained the traditional, century-old products, protected by secrecy and specific know-how from each company. Regulatory restrictions or eco-friendly certification constraints like hexane-free processes triggered an important brainstorming in the industry. As a result, we developed new eco-friendly processes including supercritical CO2 extraction, allowing fresh plants to be used to obtain industrial flower extracts (Jasmine Grandiflorum, Jasmine Sambac, Orange blossom). These extracts are analyzed by GC, GC/MS, GCO, and HPTLC techniques. New or unusual raw materials can also be explored, but the resulting extracts have to be tested for safety reasons. Some examples are described. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.
Repeated extraction of DNA from FTA cards
DEFF Research Database (Denmark)
Stangegaard, Michael; Ferrero, Laura; Børsting, Claus
Extraction of DNA using magnetic bead based techniques on automated DNA extraction instruments provides a fast, reliable and reproducible method for DNA extraction from various matrices. However, the yield of extracted DNA from FTA-cards is typically low. Here, we demonstrate that it is possible...... to repeatedly extract DNA from the processed FTA-disk. The method increases the yield from the nanogram range to the microgram range....
Supercritical fluid extraction behaviour of polymer matrices
International Nuclear Information System (INIS)
Sujatha, K.; Kumar, R.; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R.
Organic compounds present in polymeric matrices such as neoprene, surgical gloves and PVC were co-extracted during the removal of uranium using supercritical fluid extraction (SFE) technique. Hence SFE studies of these matrices were carried out to establish the extracted species using HPLC, IR and mass spectrometry techniques. The initial study indicated that uranium present in the extract could be purified from the co-extracted organic species. (author)
Chromatographic analysis of wheatgrass extracts
Directory of Open Access Journals (Sweden)
Masood Shah Khan
Full Text Available Aim: Wheatgrass (WG is the shoot of Triticum aestivum Linn. belongs to the family Gramineae, and possess high chlorophyll content and essential vitamins, minerals, vital enzymes, amino acids, dietary fibers etc., It has been shown to possess anti-cancer, anti-ulcer, antioxidant, and anti-arthritic activity due to the presence of biologically active compounds, and minerals. Therefore, in the present study, high-performance thin layer chromatography (HPTLC, and high-performance liquid chromatography (HPLC methods for qualitative and quantitative analysis have been proposed, which will help in quality evaluation of wheat grass extract. Materials and Methods: Samples for analysis were prepared in methanol and water simply by sonication. These were applied on pre-coated silica plate and chromatograms were developed using toluene: Ethyl acetate: Formic acid. HPLC analysis was done on Waters HPLC system using water, methanol, and acetonitrile as mobile phase. Merck C18 column has been used. Results: HPTLC finger printing of alcoholic extracts of WG was carried out and found 10–11 spots at different wavelengths 254, 366, and 435 nm. HPLC fingerprinting produced 22 peaks at 256 nm. Quantitative HPTLC analysis was done to determine the gallic acid content, and was found to be 0.077% w/w in aqueous extract. By HPLC, the content of gallic acid and rutin was found to be 0.07%, and 0.04% w/w in aqueous extract of WG. Conclusion: The developed HPLC and HPTLC fingerprinting method can be used for the quality control, and standardization of WG and its extracts used as nutritional supplement.
Solvent extraction of aurocyanide by extractant CTMAB and TBP
International Nuclear Information System (INIS)
Yan Wenfei; Zhang Tianxi; Wu Jinguang
A novel extraction system using KAu(CN) 2 -CTMAB as aqueous phase and 30% TBP-dodecane as organic phase is studied by 198 Au radioactive tracer and FT-IR spectroscopy. The results show that the organic phase separates into two phases, when the gold concentration is bigger than 20 g/L. From the analysis of FT-IR it is seen that the most of gold is in the lower organic phase
Recent trends in metals extraction
Directory of Open Access Journals (Sweden)
Regel-Rosocka, M.
Full Text Available After near 70 years of practical usage, solvent extraction is a perfectly mastered technique of separation, widely used on an industrial scale for the separation of metals mainly from raw materials. However, currently, in the era of depleting natural resources and increasingly less accessible deposits, environmental restrictions, etc., an increasing interest, both from social and economical constrains, is being directed at the extraction of metals from the secondary sources (such as batteries, electronic scrap. In many cases, solvent extraction, due to its operational characteristics, can be considered as the Best Available Technology for the purpose of separating multielemental metal solutions. This paper provides a brief overview of past achievements and present scenario of solvent extraction investigations and developments, describing some recently commissioned solvent extraction plants, whereas the Skorpion Zinc plant (Namibia for zinc extraction from raw materials and caesium removal from radioactive High Level Wastes (HLWs are told over in detail as case studies. The paper also presents some proposals for the use of liquid-liquid extraction to separate metal ions from secondary sources (e.g. cobalt from industrial waste streams. The review highlights the emerging use of ionic liquids as new extractants for metals, providing an insight into this exciting research field. Despite its detractors, solvent extraction has entered in force into XXI century as a leading separation technology for metals.Después de casi 70 años de uso práctico, la extracción líquido-líquido o extracción con disolventes es una técnica de separación muy evolucionada, utilizándose a escala industrial en el beneficio de metales obtenidos de diversas materias primas. Sin embargo, con el agotamiento de los recursos naturales y el aumento de depósitos minerales de más difícil acceso, restricciones medio ambientales, etc., ha aumentado el interés, tanto desde
A comparative study of Averrhoabilimbi extraction method
Zulhaimi, H. I.; Rosli, I. R.; Kasim, K. F.; Akmal, H. Muhammad; Nuradibah, M. A.; Sam, S. T.
In recent year, bioactive compound in plant has become a limelight in the food and pharmaceutical market, leading to research interest to implement effective technologies for extracting bioactive substance. Therefore, this study is focusing on extraction of Averrhoabilimbi by different extraction technique namely, maceration and ultrasound-assisted extraction. Fewplant partsof Averrhoabilimbiweretaken as extraction samples which are fruits, leaves and twig. Different solvents such as methanol, ethanol and distilled water were utilized in the process. Fruit extractsresult in highest extraction yield compared to other plant parts. Ethanol and distilled water have significant role compared to methanol in all parts and both extraction technique. The result also shows that ultrasound-assisted extraction gave comparable result with maceration. Besides, the shorter period on extraction process gives useful in term of implementation to industries.
Extracting messages masked by chaos
International Nuclear Information System (INIS)
Perez, G.; Cerdeira, H.A.
We show how to extract messages that are masked by a chaotic signal in a system of two Lorenz oscillators. This mask removal is done for two different modes of transmission, a digital one where a parameter of the sender is switched between two values, and an analog mode, where a small amplitude message is added to the carrier signal. We achieve this without using a second Lorenz oscillator as receiver, and without doing a full reconstruction of the dynamics. This method is robust with respect to transformations that impede the unmasking using a Lorenz receiver, and is not affected by the broad-band noise that is inherent to the synchronization process. We also discuss the limitations of this way of extraction for messages in high frequency bands. (author). 12 refs, 4 figs
The extraction neptunium by trilaurylamine
International Nuclear Information System (INIS)
Champion, J.; Chesne, A.
The extraction by trilaurylamine of neptunium (IV) from nitric acid and sulfuric acid-nitric acid media has been studied with the aim of developing a purification process for this element. Relative to the plutonium-neptunium separation, conditions are given for the oxidation of neptunium (IV) in sulfuric acid-nitric acid medium and data are presented on the stabilisation of the + 4 oxidation state by the organic solvent. Two procedures have been developed for the simultaneous purification of the two actinides. Both are based on the trilaurylamine extraction of the tetravalent nitrate species. The first utilises a constant redox potential fixed by Fe +++ /Fe ++ couple, while in the second, valencies are determined by successive addition of nitrite and ferrous ions. Gram quantities of neptunium 237 has been recovered from plutonium process solution. Alternate procedures are suggested for the chemical processing of irradiated Np 237 . (authors) [fr
Amine synergism in uranium extraction
International Nuclear Information System (INIS)
Rinelli, G.; Abbruzzese, C.
Commercial products based on C 8 to C 12 tertiary amine mixtures are now widely used in the solvent extraction of uranium from sulphuric pregnant solutions. The satisfactory results generally obtained have never required an analysis of the synergistic effects of amine combinations similar to that carried out for the organo-phosphorus compounds. In the research described the increase in the extraction power of an organic phase composed of an amine binary mixture was studied with regard to an aqueous solution from the sulphuric acid treatment of uranium ore. On the basis of the experimental results obtained, it is possible to select the best composition of the amine mixture to ensure a percentage increase in uranium recovery. Bearing in mind the tendency for the yellow-cake price to rise, the study is considered to be a useful contribution in the context of commercial products currently available on the market. (author)
Biopolymer chitin: extraction and characterization
International Nuclear Information System (INIS)
Andrade, Sania M.B. de; Ladchumananandasivam, Rasiah
The biopolymers are materials made from renewable sources such as soybean, corn, cane sugar, cellulose and chitin. Chitin is the most abundant biopolymer found in nature, after cellulose. The chemical structure of chitin is distinguished by the hydroxyl group, of structure from cellulose, located at position C-2, which in the chitin is replaced by acetamine group. The objective of this study was to develop the chitin from exoskeletons of Litopenaeus vannamei shrimp, which are discarded as waste, causing pollutions, environmental problems and thus obtain better utilization of these raw materials. It also, show the extraction process and deacetylation of chitosan. The extraction of chitin followed steps of demineralization, desproteinization and deodorization. Chitin and chitosan were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and the thermals properties were analyzed by thermogravimetry (TG/DTG). (author)
Extractive metallurgy of the beryllium
International Nuclear Information System (INIS)
Alonso, Neusa; Capocchi, Jose Deodoro Trani
A bibliographic review is performed on the beryllium extractive metallurgy. The work describes the main type of ores and processes applied to the metallic beryllium production, beryllium oxide production using fluoride, sulfide and direct chlorination. The thermodynamic consideration are made on beryllium reduction processes, discussing the viability of the beryllium oxide and hallide reduction processes. Under the technological viewpoint, the Cu-Be alloys main production processes are discussed, and the main toxicity problems related with beryllium are mentioned
Metals extraction from sea water
International Nuclear Information System (INIS)
Chryssostomidis, C.; Larue, G.J.; Morgan, D.T.
A method and system for continuously extracting metals from sea water by deploying adsorber sheets in a suitable current of sea water, recovering the adsorber sheets after they become loaded with metal and eluting the metal from the recovered sheets. The system involves the use of hollow, perforated bobbins on which the sheets are rolled as they are recovered and through which elutant is introduced
Electrostatic septa for SPS extraction
The extraction system for the N-Area is located in LSS2 (another one for the W-Area, now abandoned, was in LSS6). The electrostatic septum consists of 4 parts, each 3 m long. It is made of W-wires, 0.12 mm thick. The nominal electric field is 100 kV/cm. See also Annual Report 1975, p.175.
Extraction of sulfuric acid with TOPO
International Nuclear Information System (INIS)
Shuyun, Xue; Yonghui, Yang; Yanzhao, Yang; Sixiu, Sun; Borong, Bao
A study on solvent extraction of sulfuric acid by tri-octylphosphine oxide (TOPO) in n-heptane has been made. Extraction coefficients of H 2 SO 4 as a function of H 2 SO 4 concentration in aqueous phase, and extractant concentrations in organic phase have been studied. The composition of extracted species, equilibrium constants of extraction reaction have been evaluated. These results are important for interpreting extraction equilibrium data of uranium(VI) or other metal ions with TOPO in sulfuric acid media. (author)
Extraction of substances assisted by ultrasound (UAE)
International Nuclear Information System (INIS)
Azuola, Rocio; Vargas, Pedro
Different compounds present in vegetables with functional or technological properties, have gained great importance in food, pharmaceutical and cosmetic markets. Efficient methods, economical and environment friendly are sought for the extraction of these substances. A literature review has been performanced of recent publications on different extraction methods and their comparison to the ultrasound assisted extraction (UAE) to assess their effectiveness and industrial viability. The ultrasound assisted extraction (UAE) has been found to be more efficient than traditional mining methods, and cheaper and easier than non-traditional extraction methods such as microwave-assisted extraction, so it checks its industrial viability. (author) [es
Pressurized Hot Water Extraction of anthocyanins from red onion: A study on extraction and degradation rates
Energy Technology Data Exchange (ETDEWEB)
Petersson, Erik V.; Liu Jiayin; Sjoeberg, Per J.R.; Danielsson, Rolf [Uppsala University, Department of Physical and Analytical Chemistry, P.O. Box 599, SE-751 24, Uppsala (Sweden); Turner, Charlotta, E-mail: email@example.com [Uppsala University, Department of Physical and Analytical Chemistry, P.O. Box 599, SE-751 24, Uppsala (Sweden)
Pressurized Hot Water Extraction (PHWE) is a quick, efficient and environmentally friendly technique for extractions. However, when using PHWE to extract thermally unstable analytes, extraction and degradation effects occur at the same time, and thereby compete. At first, the extraction effect dominates, but degradation effects soon take over. In this paper, extraction and degradation rates of anthocyanins from red onion were studied with experiments in a static batch reactor at 110 deg. C. A total extraction curve was calculated with data from the actual extraction and degradation curves, showing that more anthocyanins, 21-36% depending on the species, could be extracted if no degradation occurred, but then longer extraction times would be required than those needed to reach the peak level in the apparent extraction curves. The results give information about the different kinetic processes competing during an extraction procedure.
DNA extraction from herbarium specimens.
Drábková, Lenka Záveská
With the expansion of molecular techniques, the historical collections have become widely used. Studying plant DNA using modern molecular techniques such as DNA sequencing plays an important role in understanding evolutionary relationships, identification through DNA barcoding, conservation status, and many other aspects of plant biology. Enormous herbarium collections are an important source of material especially for specimens from areas difficult to access or from taxa that are now extinct. The ability to utilize these specimens greatly enhances the research. However, the process of extracting DNA from herbarium specimens is often fraught with difficulty related to such variables as plant chemistry, drying method of the specimen, and chemical treatment of the specimen. Although many methods have been developed for extraction of DNA from herbarium specimens, the most frequently used are modified CTAB and DNeasy Plant Mini Kit protocols. Nine selected protocols in this chapter have been successfully used for high-quality DNA extraction from different kinds of plant herbarium tissues. These methods differ primarily with respect to their requirements for input material (from algae to vascular plants), type of the plant tissue (leaves with incrustations, sclerenchyma strands, mucilaginous tissues, needles, seeds), and further possible applications (PCR-based methods or microsatellites, AFLP).
Sequence complexity and work extraction
International Nuclear Information System (INIS)
Merhav, Neri
We consider a simplified version of a solvable model by Mandal and Jarzynski, which constructively demonstrates the interplay between work extraction and the increase of the Shannon entropy of an information reservoir which is in contact with a physical system. We extend Mandal and Jarzynski's main findings in several directions: first, we allow sequences of correlated bits rather than just independent bits. Secondly, at least for the case of binary information, we show that, in fact, the Shannon entropy is only one measure of complexity of the information that must increase in order for work to be extracted. The extracted work can also be upper bounded in terms of the increase in other quantities that measure complexity, like the predictability of future bits from past ones. Third, we provide an extension to the case of non-binary information (i.e. a larger alphabet), and finally, we extend the scope to the case where the incoming bits (before the interaction) form an individual sequence, rather than a random one. In this case, the entropy before the interaction can be replaced by the Lempel–Ziv (LZ) complexity of the incoming sequence, a fact that gives rise to an entropic meaning of the LZ complexity, not only in information theory, but also in physics. (paper)
Extractive reserves in Brazilian Amazonia
Energy Technology Data Exchange (ETDEWEB)
Fearnside, P.M (National Institute for Research in the Amazon, Manaus-Amazonas (Brazil))
In 1985 an opportunity arose for maintaining tracts of Amazonian forest under sustainable use. Brazil's National Council of Rubber Tappers and the Rural Worker's Union proposed the creation of a set of reserves of a new type, called extractive reserves. The first six are being established in one of the Brazilian states most threatened by deforestatation. The creation of extractive reserves grants legal protection to forest land traditionally used by rubber tappers, Brazil-nut gatherers, and other extractivists. The term extrativismo (extractivism) in Brazil refers to removing nontimber forest products, such as latex, resins, and nuts, without felling the trees. Approximately 30 products are collected for commercial sale. Many more types of forest materials are gathered, for example as food and medicines, for the extractivists' own use. The reserve proposal is attractive for several reasons related to social problems. It allows the rubber tappers to continue their livelihood rather than be expelled by deforestation. However, it is unlikely that sufficient land will be set aside as extractive reserves to employ all the tappers. Displaced rubber tappers already swell the ranks of urban slum dwellers in Brazil's Amazonian cities, and they have become refugees to continue their profession in the forests of neighboring countries, such as Bolivia.
Stability of extraction space closure.
Garib, Daniela Gamba; Bressane, Larissa Borges; Janson, Guilherme; Gribel, Bruno Frazão
The objectives of this study were to evaluate the prevalence and long-term behavior of extraction space reopening in patients with Class I malocclusion and to identify some associated factors. A sample of 43 patients met the inclusion criteria. Dental casts at the onset of treatment, after treatment, and 1 and 5 years after debonding were used. Initial and final cephalometric radiographs were used to measure the amount of incisor retraction. Cochran tests were used to compare the numbers of open and closed extraction spaces after treatment and at 1 and 5 years after debonding (P space reopening with t tests. Of the sample, 30.23% had extraction space reopening. The frequency of open spaces significantly increased between the final and the 1-year posttreatment dental casts and decreased between the casts at 1 and 5 years posttreatment. Patients with space reopening had less initial anterior crowding and greater amounts of mandibular incisor retraction during treatment. There was a high prevalence of space reopening 1 year after treatment. However, these spaces tended to decrease by 5 years after treatment. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Titanium metal: extraction to application
Energy Technology Data Exchange (ETDEWEB)
Gambogi, Joseph (USGS, Reston, VA); Gerdemann, Stephen J.
In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium. In this paper, we discuss all aspects of the titanium industry from ore deposits through extraction to present and future applications. The methods of both primary (mining of ore, extraction, and purification) and secondary (forming and machining) operations will be analyzed. The chemical and physical properties of titanium metal will be briefly examined. Present and future applications for titanium will be discussed. Finally, the economics of titanium metal production also are analyzed as well as the advantages and disadvantages of various alternative extraction methods.
Digital extraction of interference fringe contours
International Nuclear Information System (INIS)
Mastin, G.A.; Ghiglia, D.C.
Two basic techniques for extracting interferogram contours have been discussed. The first is a global contour extracton technique based on the fast Fourier transform. The second extracts individual contours with a thinning algorithm using logical neighborhood transformations
Directory of Open Access Journals (Sweden)
Angelica Margo
Full Text Available Decision to extract or not and the type of tooth must be analyzed carefully in orthodontic treatment. Preferable tooth to be extracted was the tooth with large caries or restoration. Usually the type of tooth to be extracted was second molar (if the third molar appears, incisor, first molar, and combination of several teeth. Orthodontic treatment with molar extraction is more difficult to treat and the result is usually compromise. There are several considerations in extracting first molar such as tooth with large caries or restoration, hypoplasia, periapical disease, large discrepancy, high maxilla-mandibular plane angle, and cases with anterior open bite. Nowadays, orthodontic cases with molar extraction do not prolong the treatment time compared to premolar extraction case, but the anchorage system must be considered carefully. The present case was treated with extraction of first molar to solve anterior crowding with maximum anchorage at the upper jaw and using Nance Holding Appliance.
Portulaca oleracea Linn seed extract ameliorates hydrogen ...
African Journals Online (AJOL)
Portulaca oleracea Linn seed extract ameliorates hydrogen ... induced cell death by inhibiting oxidative stress and ROS generation. Keywords: ... culture medium; therefore the stock solutions of ... acetic acid (1 %) and ethanol (50 %) to extract.
EVALUATION OF EXTRACTS FROM Tapinanthus dodone ...
African Journals Online (AJOL)
flavonoids, tannins, saponins, glycosides ethanolic leaf extract from ... of Chemistry, Kano University of Science and Technology, Wudil. P.M.B. 3244, Kano ... ethanolic leaf extract from Tapinanthus dodoneifolius grown ee. Results obtained for ...
Inflation of Unreefed and Reefed Extraction Parachutes
Ray, Eric S.; Varela, Jose G.
Data from the Orion and several other test programs have been used to reconstruct inflation parameters for 28 ft Do extraction parachutes as well as the parent aircraft pitch response during extraction. The inflation force generated by extraction parachutes is recorded directly during tow tests but is usually inferred from the payload accelerometer during Low Velocity Airdrop Delivery (LVAD) flight test extractions. Inflation parameters are dependent on the type of parent aircraft, number of canopies, and standard vs. high altitude extraction conditions. For standard altitudes, single canopy inflations are modeled as infinite mass, but the non-symmetric inflations in a cluster are modeled as finite mass. High altitude extractions have necessitated reefing the extraction parachutes, which are best modeled as infinite mass for those conditions. Distributions of aircraft pitch profiles and inflation parameters have been generated for use in Monte Carlo simulations of payload extractions.
Transductive Pattern Learning for Information Extraction
National Research Council Canada - National Science Library
McLernon, Brian; Kushmerick, Nicholas
.... We present TPLEX, a semi-supervised learning algorithm for information extraction that can acquire extraction patterns from a small amount of labelled text in conjunction with a large amount of unlabelled text...
Uranium extraction from gold-uranium ores
Energy Technology Data Exchange (ETDEWEB)
Laskorin, B.N.; Golynko, Z.Sh.
The process of uranium extraction from gold-uranium ores in the South Africa is considered. Flowsheets of reprocessing gold-uranium conglomerates, pile processing and uranium extraction from the ores are presented. Continuous counter flow ion-exchange process of uranium extraction using strong-active or weak-active resins is noted to be the most perspective and economical one. The ion-exchange uranium separation with the succeeding extraction is also the perspective one.
Solvent extraction studies of RERTR silicide fuels
International Nuclear Information System (INIS)
Gouge, Anthony P.
Uranium silicide fuels, which are candidate RERTR fuel compositions, may require special considerations in solvent extraction reprocessing. Since Savannah River Plant may be reprocessing RERTR fuels as early as 1985, studies have been conducted at Savannah River Laboratory to demonstrate the solvent extraction behavior of this fuel. Results of solvent extraction studies with both unirradiated and irradiated fuel are presented along with the preliminary RERTR solvent extraction reprocessing flow sheet for Savannah River Plant. (author)
Equipment for extracting and conveying stratified minerals
Energy Technology Data Exchange (ETDEWEB)
Blumenthal, G.; Kunzer, H.; Plaga, K.
This invention relates to equipment for extracting stratified minerals and conveying the said minerals along the working face, comprising a trough shaped conveyor run assembled from lengths, a troughed extraction run in lengths matching the lengths of conveyor troughing, which is linked to the top edge of the working face side of the conveyor troughing with freedom to swivel vertically, and a positively guided chain carrying extraction tools and scrapers along the conveyor and extraction runs.
Accelerated Solvent Extraction: An Innovative Sample Extraction Technique for Natural Products
International Nuclear Information System (INIS)
Hazlina Ahmad Hassali; Azfar Hanif Abd Aziz; Rosniza Razali
Accelerated solvent extraction (ASE) is one of the novel techniques that have been developed for the extraction of phytochemicals from plants in order to shorten the extraction time, decrease the solvent consumption, increase the extraction yield and enhance the quality of extracts. This technique combines elevated temperatures and pressure with liquid solvents. This paper gives a brief overview of accelerated solvent extraction technique for sample preparation and its application to the extraction of natural products. Through practical examples, the effects of operational parameters such as temperature, volume of solvent used, extraction time and extraction yields on the performance of ASE are discussed. It is demonstrated that ASE technique allows reduced solvent consumption and shorter extraction time, while the extraction yields are even higher than those obtained with conventional methods. (author)
Extraction chromatogrpahy of actinides, ch. 7
International Nuclear Information System (INIS)
Mueller, W.
This review on extraction chromatography of actinides emphasizes the important usage of neutral (Tributylphosphate), basic (substituted ammonium salts), and acidic (HDEHP) extractants, and their application to separations of actinides in the di-to hexavalent oxidation state. Furthermore, the actinide extraction by ketones, ethers, alcohols and β-diketones is discussed
Surfactant enhanced non-classical extraction
International Nuclear Information System (INIS)
Szymanowski, J.
Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilisation abilities are also discussed. (author)
Extractions of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a former manufactured gas plant site were performed with a Soxhlet apparatus (18 h), by pressurized liquid extraction (PLE) (50 min at 100°C), supercritical fluid extraction (SFE) (1 h at 150°...
Determining efficient extraction procedure of phytochemicals from ...
African Journals Online (AJOL)
Determining efficient extraction procedure of phytochemicals from the fruit paste of Ziziphus abyssinica and Tamarindus indica . ... Methodology and results: The methods used included cold and soxhlet extraction using methanol as the solvent and hot extraction using distilled water. To determine the efficiency in which ...
Surfactant enhanced non-classical extraction
International Nuclear Information System (INIS)
Szymanowski, J.
Surfactant enhanced non-classical extractions are presented and discussed. They include micellar enhanced ultrafiltration and cloud point extraction. The ideas of the processes are given and the main features are presented. They are compared to the classical solvent extraction. The fundamental of micellar solutions and their solubilization abilities are also discussed. (author)
Organization of extracting molecules of the diamide type: link with the extracting properties?
International Nuclear Information System (INIS)
Meridiano, Y.
The aim of these studies is to establish a link between the different organizations of diamide extractants (used in the DIAMEX process) and their extracting properties. The effects of the key parameters leading the liquid-liquid extraction (concentration of extractant, nature of solute, activity of the aqueous phase, nature of the diluent and temperature) are studied: 1) at the supramolecular scale, with the characterization of the extractant organizations by vapor-pressure osmometry (VPO) and small angle neutron and X-ray scattering (SANS/SAXS) experiments; 2) at the molecular scale, with the quantification of the extracted solutes (water, nitric acid, metal nitrate) and the determination of extracted complexes stoichiometries by electro-spray mass spectrometry (ESI-MS) experiments. The DMDOHEMA molecule acts as a classical surfactant and forms aggregates of the reverse micelle type. Taking into account the established supramolecular diagrams, a quantitative link between the extractants structures and their extracting properties has been brought to light. To model the europium nitrate extraction, two approaches have been developed: - an approach based on mass action laws. Extractions equilibria have been proposed taking into account the supramolecular speciation; - an innovative approach considering the extracted ions as adsorbed on a specific surface of the extractant molecule which depends on the extractant organization state. The ion extraction can be considered as a sum of isotherms corresponding to the different states of organization. This approach allows to compare the extraction efficiency of an extracting molecule as a function of its organization state. (author)
Hybrid Model of Content Extraction
DEFF Research Database (Denmark)
Qureshi, Pir Abdul Rasool; Memon, Nasrullah
We present a hybrid model for content extraction from HTML documents. The model operates on Document Object Model (DOM) tree of the corresponding HTML document. It evaluates each tree node and associated statistical features like link density and text distribution across the node to predict...... significance of the node towards overall content provided by the document. Once significance of the nodes is determined, the formatting characteristics like fonts, styles and the position of the nodes are evaluated to identify the nodes with similar formatting as compared to the significant nodes. The proposed...
The extractive metallurgy of gold
Energy Technology Data Exchange (ETDEWEB)
Kongolo, K.; Mwema, M.D. [University of Lubumbashi, Zaire, Gecamines Metallurgical Research Centre, Likasi, Zaire, c/o Gecamines Brussels (Belgium)
Moessbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Moessbauer spectroscopy could be applied.
PSR extraction kicker system improvements
International Nuclear Information System (INIS)
Hardek, T.W.
A program to improve the reliability of hardware required to operate the Los Alamos Proton Storage Ring has been under way for the past three years. The extraction kicker system for the PSR was identified as one candidate for improvement. Pulse modulators produce 50kV pulses 360 nsec in length at up to 24-Hz pulse repetition rate and drive two 4-meter-long stripline electrodes. Sources of difficulty with this system included short width switch tube lifetime, drive cable electrical breakdown, high-voltage connector failure, and occasional electrode breakdown. This paper discusses modifications completed on this system to correct these difficulties. 2 refs., 3 figs
The extractive metallurgy of gold
Kongolo, K.; Mwema, M. D.
Mössbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Mössbauer spectroscopy could be applied.
The extractive metallurgy of gold
International Nuclear Information System (INIS)
Kongolo, K.; Mwema, M.D.
Moessbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Moessbauer spectroscopy could be applied
Keyword extraction by nonextensivity measure.
Mehri, Ali; Darooneh, Amir H
The presence of a long-range correlation in the spatial distribution of a relevant word type, in spite of random occurrences of an irrelevant word type, is an important feature of human-written texts. We classify the correlation between the occurrences of words by nonextensive statistical mechanics for the word-ranking process. In particular, we look at the nonextensivity parameter as an alternative metric to measure the spatial correlation in the text, from which the words may be ranked in terms of this measure. Finally, we compare different methods for keyword extraction. © 2011 American Physical Society
Primary metals extraction by liquid membranes
International Nuclear Information System (INIS)
Subramanian, K.N.
The extraction of copper and uranium by liquid membranes is presented. The recovery of uranium from wet process phosphoric acid is described. The development of this process has progressed through three stages, firstly the chemistry of uranium extraction as it pertains to liquid membrane systems. This was followed by continuous extraction tests on fresh black acid and on aged acid. Results on a 1 litre/minute pilot plant demonstrated that the process could be operated with a minimum of feed pretreatment and about 90% of uranium could be extracted. The extraction of copper from copper leach liquors is also described. (U.K.)
Extraction of uranyl sulfate with primary amine
International Nuclear Information System (INIS)
Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.
PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)
Wind Extraction for Natural Ventilation
Fagundes, Tadeu; Yaghoobian, Neda; Kumar, Rajan; Ordonez, Juan
Due to the depletion of energy resources and the environmental impact of pollution and unsustainable energy resources, energy consumption has become one of the main concerns in our rapidly growing world. Natural ventilation, a traditional method to remove anthropogenic and solar heat gains, proved to be a cost-effective, alternative method to mechanical ventilation. However, while natural ventilation is simple in theory, its detailed design can be a challenge, particularly for wind-driven ventilation, which its performance highly involves the buildings' form, surrounding topography, turbulent flow characteristics, and climate. One of the main challenges with wind-driven natural ventilation schemes is due to the turbulent and unpredictable nature of the wind around the building that impose complex pressure loads on the structure. In practice, these challenges have resulted in founding the natural ventilation mainly on buoyancy (rather than the wind), as the primary force. This study is the initial step for investigating the physical principals of wind extraction over building walls and investigating strategies to reduce the dependence of the wind extraction on the incoming flow characteristics and the target building form.
Injection and extraction for cyclotrons
International Nuclear Information System (INIS)
Heikkinen, P.
External ion sources for cyclotrons are needed for polarised and heavy ions. This calls for injection systems, either radial or axial. Radial injection is also needed when a cyclotron works as a booster after another cyclotron or a linear accelerator (usually tandem). Requirements for injection differ from separated sector cyclotrons where there is plenty of room to house inflectors and/or strippers, to superconducting cyclotrons where the space is limited by a small magnet gap, and high magnetic field puts other limitations to the inflectors. Several extraction schemes are used in cyclotrons. Stripping injection is used for H - and also for heavy ions where the q/m ratio is usually doubled. For other cases, electric and magnetic deflection has to be used. To increase the turn separation before the first deflector, both resonant and non-resonant schemes are used. In this lecture, external injection systems are surveyed and some rules to thumb for injection parameters are given. Extraction schemes are also reviewed. (orig.)
Solar Filament Extraction and Characterizing
Yuan, Yuan; Shih, F. Y.; Jing, J.; Wang, H.
This paper presents a new method to extract and characterize solar filaments from H-alpha full-disk images produced by Big Bear Solar Observatory. A cascading Hough Transform method is designed to identify solar disk center location and radius. Solar disks are segmented from the background, and unbalanced illumination on the surface of solar disks is removed using polynomial surface fitting. And then a localized adaptive thresholding is employed to extract solar filament candidates. After the removal of small solar filament candidates, the remaining larger candidates are used as the seeds of region growing. The procedure of region growing not only connects broken filaments but also generate complete shape for each filament. Mathematical morphology thinning is adopted to produce the skeleton of each filament, and graph theory is used to prune branches and barbs to get the main skeleton. The length and the location of the main skeleton is characterized. The proposed method can help scientists and researches study the evolution of solar filament, for instance, to detect solar filament eruption. The presented method has already been used by Space Weather Research Lab of New Jersey Institute of Technology (http://swrl.njit.edu) to generate the solar filament online catalog using H-alpha full-disk images of Global H-alpha Network (http://swrl.njit.edu/ghn_web/).
Directory of Open Access Journals (Sweden)
Botond BENEDEK
Full Text Available In the Internet world, the amount of information available reaches very high quotas. In order to find specific information, some tools were created that automatically scroll through the existing web pages and update their databases with the latest information on the Internet. In order to systematize the search and achieve a result in a concrete form, another step is needed for processing the information returned by the search engine and generating the response in a more organized form. Centralizing events of a certain type is useful first of all for creating a news service. Through this system we are pursuing a knowledge - events from the Internet documents - extraction system. The system will recognize events of a certain type (weather, sports, politics, text data mining, etc. depending on how it will be trained (the concept it has in the dictionary. These events can be provided to the user, or it can also extract the context in which the event occurred, to indicate the initial form in which the event was embedded.
30 CFR 947.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 947.702 Section 947.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...
30 CFR 933.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 933.702 Section 933.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...
30 CFR 939.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 939.702 Section 939.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...
30 CFR 903.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 903.702 Section 903.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...
30 CFR 912.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 912.702 Section 912.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...
30 CFR 937.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 937.702 Section 937.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...
30 CFR 921.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 921.702 Section 921.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of the chapter, Exemption for Coal Extraction Incidental to the Extraction of...
30 CFR 905.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 905.702 Section 905.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...
30 CFR 942.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 942.702 Section 942.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...
30 CFR 910.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 910.702 Section 910.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...
30 CFR 922.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 922.702 Section 922.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...
30 CFR 941.702 - Exemption for coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 941.702 Section 941.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...
30 CFR 750.21 - Coal extraction incidental to the extraction of other minerals.
... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal extraction incidental to the extraction of... ENFORCEMENT, DEPARTMENT OF THE INTERIOR INDIAN LANDS PROGRAM REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS ON INDIAN LANDS § 750.21 Coal extraction incidental to the extraction of other minerals...
Supercritical fluid extraction of uranium from tissue paper matrix using organic extractants
International Nuclear Information System (INIS)
Kanekar, A.S.; Bhattacharyya, A.; Pathak, P.N.; Mohapatra, P.K.; Manchanda, V.K.
Direct extraction of dried uranyl nitrate from tissue paper matrix was carried out using supercritical carbon dioxide modified with methanol solutions of extractants such as tri-n-butyl phosphate (TBP) and di-n-hexyl octanamide (DHOA)). The effects of temperature, pressure, extractant and nitric acid concentration on the extraction of uranyl ion were investigated. (author)
[Study on condition for extraction of arctiin from fruits of Arctium lappa using supercritical fluid extraction].
Dong, Wen-hong; Liu, Ben
To study the feasibility of supercritical fluid extraction (SFE) for arctiin from the fruits of Arctium lappa. The extracts were analyzed by HPLC, optimum extraction conditions were studied by orthogonal tests. The optimal extraction conditions were: pressure 40 MPa, temperature 70 degrees C, using methanol as modifier carrier at the rate of 0.55 mL x min(-1), static extraction time 5 min, dynamic extraction 30 min, flow rate of CO2 2 L x min(-1). SFE has the superiority of adjustable polarity, and has the ability of extracting arctiin.
Clinical evaluation of postradiation dental extraction
International Nuclear Information System (INIS)
Kusukawa, Jingo; Ohisi, Shinichiro; Kameyama, Tadamitsu; Yoshizumi, Munehiro; Hayabuchi, Naofumi
Twenty-one patients who had undergone postradiation dental extraction were evaluated clinically. All patients had received irradiation for primary head and neck malignancies at doses ranging from 8 to 60 Gy (mean, 51.6 Gy). Time to dental extraction after irradiation ranged from 8 to 156 months (mean, 57.9 months). Of the 21 patients (80 teeth extracted, including 33 maxillary teeth and 47 mandibular teeth), one had delayed healing after wisdom tooth extraction due to postextraction irradiation. Thus, osteoradionecrosis after dental extraction did not develop. These results suggest that dental extraction after radiation is not contraindicated. To prevent complications, patients who have received radiation and require extractions should be cared for by oral and maxillofacial surgeons in close association with radiation oncologists. (author)
Solvent extraction of noble metals by formazans
International Nuclear Information System (INIS)
Grote, M.; Hueppe, U.; Kettrup, A.
The extraction properties of ion-pairs composed of quaternary ammonium cations and a sulphonated formazan were compared with those of an unsulphonated formazan, for various solvent media. In dichloromethane the combined system behaves as a 'coloured anion-exchanger', with displacement of the sulphonated formazan, whereas in toluene Pd(II) and Ag(I) are extracted as the metal formazan chelates from aqueous medium. The rates of extraction are remarkably higher than with the simple extractants. Because of the higher stability only the simple chelating extraction systems afford satisfactory separation of Pd(II) from excess of Pt(IV) and of Ag(I) from Cu(II). The extracted metals can be stripped and the extractant regenerated. (author)
Extraction of some acids using aliphatic amines
International Nuclear Information System (INIS)
Matutano, L.
Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [fr
Inhibition of aluminum corrosion using Opuntia extract
International Nuclear Information System (INIS)
El-Etre, A.Y.
The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions
Extraction efficiency of hydrophilic and lipophilic antioxidants from lyophilized foods using pressurized liquid extraction and manual extraction.
Watanabe, Jun; Oki, Tomoyuki; Takebayashi, Jun; Takano-Ishikawa, Yuko
The efficient extraction of antioxidants from food samples is necessary in order to accurately measure their antioxidant capacities. α-Tocopherol and gallic acid were spiked into samples of 5 lyophilized and pulverized vegetables and fruits (onion, cabbage, Satsuma mandarin orange, pumpkin, and spinach). The lipophilic and hydrophilic antioxidants in the samples were sequentially extracted with a mixed solvent of n-hexane and dichloromethane, and then with acetic acid-acidified aqueous methanol. Duplicate samples were extracted: one set was extracted using an automated pressurized liquid extraction apparatus, and the other set was extracted manually. Spiked α-tocopherol and gallic acid were recovered almost quantitatively in the extracted lipophilic and hydrophilic fractions, respectively, especially when pressurized liquid extraction was used. The expected increase in lipophilic oxygen radical absorbance capacity (L-ORAC) due to spiking with α-tocopherol, and the expected increase in 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and total polyphenol content due to spiking with gallic acid, were all recovered in high yield. Relatively low recoveries, as reflected in the hydrophilic ORAC (H-ORAC) value, were obtained following spiking with gallic acid, suggesting an interaction between gallic acid and endogenous antioxidants. The H-ORAC values of gallic acid-spiked samples were almost the same as those of postadded (spiked) samples. These results clearly indicate that lipophilic and hydrophilic antioxidants are effectively extracted from lyophilized food, especially when pressurized liquid extraction is used. © 2014 Institute of Food Technologists®
Quality Parameters of Curcuma Longa L. Extracts by Supercritical Fluid Extraction (SFE) and Ultrasonic Assisted Extraction (UAE)
International Nuclear Information System (INIS)
Zaibunnisa Abdul Haiyee; Siti Hafsah Mohd Shah; Khudzir Ismail; Nooraain Hashim; Wan Iryani Wan Ismail
Turmeric is one of the prominently use herbal plants due to its diverse beneficial effects especially in Indian medicine. The rhizome part of the turmeric contains valuable compounds which have been said to owe its antimicrobial effects, anti-cancer, anti-inflammatory and enhance wound healing. Due to its short-life span and perishable properties, the conversion of the rhizome into turmeric extract is desirable. Several methods have been used for extraction such as Soxhlet extraction and pressurized liquid extraction (PLE). However, these techniques are tedious, laborious, time consuming and involves the usage of toxic organic solvent, of which safeness of the end product is doubtful. In this study, a rapid, reliable and green extraction method of supercritical fluid extraction (SFE) and ultrasonic assisted extraction (UAE) were used. SFE without modifier has resulted in 0.0006 mg/ 100 g of curcuminoids concentration and 5.62 % of yield (dry weight basis). UAE using ethanol was able to produce significantly the highest yield (6.40 %, dry weight basis) and the highest curcuminoids concentration (0.1020 mg/ 100 g). However, SFE was able to produce extract that contain significantly higher major volatile compounds; tumerone, ar-turmerone and curlone. Therefore, this study proves that both extraction methods were able to produce high quality turmeric extract. (author)
Chemical Profiling of Acalypha Indica Obtained from Supercritical Carbon Dioxide Extraction and Soxhlet Extraction Methods
Surangkana Chaichoowong; Jan Bernd Bol; Pornprapa Bol; Thomas Gamse; Malinee Sriariyanun
Acalypha indica is a weed that grows in South-East Asia. It contains several valuable compounds that can be used for curing various diseases such as rheumatism, skin infection and blood dysentery. Here, the extraction of A. indica using Soxhlet extraction with two different solvents and supercritical CO2 extraction (SCE) with two different temperatures (40 and 60°C) was performed. In Soxhlet extraction, ethanol solvent provided the highest extraction yield of 34.36%. For SCE, the increased te...
Extraction and Quantitative HPLC Analysis of Coumarin in Hydroalcoholic Extracts of Mikania glomerata Spreng: ("guaco" Leaves
Directory of Open Access Journals (Sweden)
Celeghini Renata M. S.
Full Text Available Methods for preparation of hydroalcoholic extracts of "guaco" (Mikania glomerata Spreng. leaves were compared: maceration, maceration under sonication, infusion and supercritical fluid extraction. Evaluation of these methods showed that maceration under sonication had the best results, when considering the ratio extraction yield/extraction time. A high performance liquid chromatography (HPLC procedure for the determination of coumarin in these hydroalcoholic extracts of "guaco" leaves is described. The HPLC method is shown to be sensitive and reproducible.
Changing perspectives on resource extraction.
Gibson, Hazel; Stewart, Iain; Pahl, Sabine; Stokes, Alison
Over the last century, resource extraction in the UK has changed immeasurably; from relatively small-scale, manually-operated facilities to the larger technological advanced sites that exist today. The communities that live near these sites have also changed, from housing workers that were as much of a resource as the geological material, to local residents who are environmentally literate and strongly value their landscape. Nowadays great pressure is put on the extractive industry to work in both environmentally sustainable and socially ethical ways, but how does this impact upon the local population? How do communities perceive the resource extraction that neighbours them? And is this perception rooted in a general understanding of geology and the subsurface? To explore resident's perceptions of the geological environment, three villages in the southwest of England have been investigated, using a mixed-methods mental models approach. The villages were selected as each has a different geological setting, both commercially and culturally. The first village has a strong historical geological identity, but little current geological activity. The second village has a large tungsten mine in the process of beginning production. The third village has no obvious cultural or commercial relationships with geology and acts as the control site. A broad sample from each of the three villages was qualitatively interviewed, the results of which were analyzed using an emergent thematic coding scheme. These qualitative results were then modelled using Morgan et al's mental models method (2002) and tested using a quantitative questionnaire. The results of this mixed method approach reveals the principal perceptions (or mental models) of residents in these three villages. The villages each present a different general perception of resource exploitation, which appears to be culturally driven, with the first village having the most positive correlations. These mental models are
Extracting information from multiplex networks
Iacovacci, Jacopo; Bianconi, Ginestra
Multiplex networks are generalized network structures that are able to describe networks in which the same set of nodes are connected by links that have different connotations. Multiplex networks are ubiquitous since they describe social, financial, engineering, and biological networks as well. Extending our ability to analyze complex networks to multiplex network structures increases greatly the level of information that is possible to extract from big data. For these reasons, characterizing the centrality of nodes in multiplex networks and finding new ways to solve challenging inference problems defined on multiplex networks are fundamental questions of network science. In this paper, we discuss the relevance of the Multiplex PageRank algorithm for measuring the centrality of nodes in multilayer networks and we characterize the utility of the recently introduced indicator function Θ ˜ S for describing their mesoscale organization and community structure. As working examples for studying these measures, we consider three multiplex network datasets coming for social science.
Adaptive web data extraction policies
Directory of Open Access Journals (Sweden)
Provetti, Alessandro
Full Text Available Web data extraction is concerned, among other things, with routine data accessing and downloading from continuously-updated dynamic Web pages. There is a relevant trade-off between the rate at which the external Web sites are accessed and the computational burden on the accessing client. We address the problem by proposing a predictive model, typical of the Operating Systems literature, of the rate-of-update of each Web source. The presented model has been implemented into a new version of the Dynamo project: a middleware that assists in generating informative RSS feeds out of traditional HTML Web sites. To be effective, i.e., make RSS feeds be timely and informative and to be scalable, Dynamo needs a careful tuning and customization of its polling policies, which are described in detail.
Nickel extraction from nickel matte
Subagja, R.
In present work, the results of research activities to make nickel metal from nickel matte are presented. The research activities were covering a) nickel matte characterization using Inductively Couple plasma (ICP), Electron Probe Micro Analyzer (EPMA) and X-Ray Diffraction (XRD), b) nickel matte dissolution process to dissolve nickel from nickel matte into the spent electrolyte solutions that contains hydrochloric acid, c) purification of nickel chloride leach solution by copper cementation process to remove copper using nickel matte, selective precipitation process to remove iron, solvent extraction using Tri normal octyl amine to separate cobalt from nickel chloride solutions and d) Nickel electro winning process to precipitate nickel into the cathode surface from purified nickel chloride solution by using direct current. The research activities created 99, 72 % pure nickel metal as the final product of the process.
Extractive {sup 90}Y generator
Energy Technology Data Exchange (ETDEWEB)
Kodina, G.E. [State Scientific Center, Moscow (Russian Federation). Institute of Giophysics; Korpusov, G.V.; Filyanin, A.T. [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Physical Chemistry
The generator for {sup 90}Y production is made up of two units - an extractive unit and a unit for deep purification. Contrary to the well-known methods of {sup 90}Y separation two mineral acids are used in the developed technology. The solutions of nitric acid are used for preliminary separation of {sup 90}Y and the solutions of hydrochloric acid are used for the deep purification of {sup 90}Y from {sup 90}Sr and stripping. The optimum conditions for carrying out this technology were found. The following results are reported: the carry-over of the stationary phase is excluded in this generator; the separation time is 30-60 minutes; the yield of the final product is not less than 95%; impurity of {sup 90}Sr is not more than 10{sup -9-}-{sup -10}%; the content of the chemical (nonactive) impurities is not more than the allowed one for radiopharmaceuticals 4 refs., 4 tabs., 5 figs.
Incremental Observer Relative Data Extraction
DEFF Research Database (Denmark)
Bukauskas, Linas; Bøhlen, Michael Hanspeter
The visual exploration of large databases calls for a tight coupling of database and visualization systems. Current visualization systems typically fetch all the data and organize it in a scene tree that is then used to render the visible data. For immersive data explorations in a Cave...... or a Panorama, where an observer is data space this approach is far from optimal. A more scalable approach is to make the observer-aware database system and to restrict the communication between the database and visualization systems to the relevant data. In this paper VR-tree, an extension of the R......-tree, is used to index visibility ranges of objects. We introduce a new operator for incremental Observer Relative data Extraction (iORDE). We propose the Volatile Access STructure (VAST), a lightweight main memory structure that is created on the fly and is maintained during visual data explorations. VAST...
Clinical utility of curcumin extract.
Asher, Gary N; Spelman, Kevin
Turmeric root has been used medicinally in China and India for thousands of years. The active components are thought to be the curcuminoids, primarily curcumin, which is commonly available worldwide as a standardized extract. This article reviews the pharmacology of curcuminoids, their use and efficacy, potential adverse effects, and dosage and standardization. Preclinical studies point to mechanisms of action that are predominantly anti-inflammatory and antineoplastic, while early human clinical trials suggest beneficial effects for dyspepsia, peptic ulcer, inflammatory bowel disease, rheumatoid arthritis, osteoarthritis, uveitis, orbital pseudotumor, and pancreatic cancer. Curcumin is well-tolerated; the most common side effects are nausea and diarrhea. Theoretical interactions exist due to purported effects on metabolic enzymes and transport proteins, but clinical reports do not support any meaningful interactions. Nonetheless, caution, especially with chemotherapy agents, is advised. Late-phase clinical trials are still needed to confirm most beneficial effects.
Topic extraction from adverbial clauses
Directory of Open Access Journals (Sweden)
Carlos Rubio Alcalá
Full Text Available This paper offers new data to support findings about Topic extraction from adverbial clauses. Since such clauses are strong islands, they should not allow extraction of any kind, but we show here that if the appropriate conditions are met, Topics of the CLLD kind in Romance can move out of them. We propose that two conditions must be met for such movement to be possible: the first is that the adverbial clause must have undergone topicalisation in the first place; the second is that the adverbial clause is inherently topical from a semantic viewpoint. Contrast with other language families (Germanic, Quechua and Japanese is provided and the semantic implications of the proposal are briefly discussed. Keywords: topicalisation; Clitic Left Dislocation; syntactic islands; adverbial clauses Este artículo ofrece nuevos datos sobre la extracción de Tópicos desde oraciones subordinadas adverbiales. Dado que dichas oraciones son islas fuertes, no deberían permitir extracción de ningún tipo, pero mostramos que si se dan las condiciones apropiadas, los Tópicos del tipo CLLD en lenguas románicas pueden desplazarse fuera de ellas. Proponemos que se deben cumplir dos condiciones para que ese movimiento sea posible: la primera es que la propia subordinada adverbial se haya topicalizado en primer lugar; la segunda es que la subordinada adverbial sea inherentemente un Tópico desde el punto de vista semántico. Proporcionamos también algunos contrastes con otras familias lingüísticas (germánica, quechua y japonés y se discuten brevemente las implicaciones semánticas de la propuesta. Palabras clave: topicalización; dislocación a la izquierda con clítico; islas sintácticas; oraciones adverbiales
Extraction of uranium from seawater
International Nuclear Information System (INIS)
Kanno, M.
The nuclear power generation is thought to be very important in Japan. However, known domestic uranium resources in Japan are very rare. So, extraction of uranium from sea water have been carried out since 1962 at Japan Tobacco and Salt Public Corporation. There are a number of results obtained also by Kyoto University, Shikoku Govenment Industrial Research Institute, Tokyo University and others. In order to investigate the technical and economical feasibility of extraction of uranium and other resources from sea water, a research program was started in fiscal 1975, sponsored by the Ministry of International Trade and Industry with the budget of about $440,000. In this program, the conceptional design of two types of model plants, the ''column type'' and the ''tidal type'' was drawn on the design bases set up with available information. It was found that there has been several problems waiting solution, but there were no technically fatal problems. Adsorption tests were carried out with adsorbents of more than eleven types, including titanium hydroxide, and it was found that titanium hydroxide made by titanyl surphate and urea had the largest adsorption capacity of uranium among them. Elution experiments were performed only with ammonium carbonate and the efficiency at the temperature of 60 0 C showed three times higher than that of 20 0 C. A few long term column operation was conducted, mainly with the adsorbent of granulated titanium hydroxide for 15-60 days. The maximum yield of uranium throughout the adsorption and elution operation was over 20% and macimum concentration of uranium in eluate was 7 ppm
Bioactivity of Neem (Azadirachta indica) callus extract
International Nuclear Information System (INIS)
Ahmed, I.M.
This study was conducted in order to explore the possibility of utilizing plant tissue culture techniques for production of secondary metabolites from callus culture of Azadirachta indica (Neem) and to investigate the bioactivity of the established callus extract in comparison with the extract from the intact leaves. The presence of secondary metabolites in the extracts was detected by Thin Layer Chromatography (TLC). Both the callus and leaf extracts eluted five fraction of compounds and it were observed that callus extract had a good resolution. various extract concentration (5.10. and 20 mg/ml) were determined for the rate and extent of inhibition kinetics against staphylococcus aureus. Escherichia coli, and candida albicans. Results showed that callus extract of A. indica wiped out all viable cells of C. albicans within 18 hours and the subsequent concentration 5 and 10 mg/ m1 retard the growth after 24 h. A higher concentration of 20 mg/ ml had the same effect on S. aureus after 6 h and the E. coli cells were completely inhibited by the extracts after 24 h. Similar kinetics were showed by leaf extract but in slight rate as compared to the callus extract. In general both extract posses antimicrobial activity with notable efficient rates. For assaying of the inhibitory effect on some phyto pathogens the effect of different concentrations of the callus and leaf extracts on the radial growth of Drechslera rostrata. Fusarium oxysporum and Alterneria alternata were in vitro assessed. Obvious inhibitory effect was observed on the mycelia radial growth of the three treated fungi. The level of inhibition increased with the increase of te extract concentration. The maximum inhibitory effect (84%) was recorded with Drechslera rostrata when inoculated in media contain 20 mg/ ml of callus while the inhibition rate of mycelia growth of the same species reaches 61% when inoculated in a medium contain the same concentration of the neem leaf extract. The subsequent
Modeling and prediction of extraction profile for microwave-assisted extraction based on absorbed microwave energy.
Chan, Chung-Hung; Yusoff, Rozita; Ngoh, Gek-Cheng
A modeling technique based on absorbed microwave energy was proposed to model microwave-assisted extraction (MAE) of antioxidant compounds from cocoa (Theobroma cacao L.) leaves. By adapting suitable extraction model at the basis of microwave energy absorbed during extraction, the model can be developed to predict extraction profile of MAE at various microwave irradiation power (100-600 W) and solvent loading (100-300 ml). Verification with experimental data confirmed that the prediction was accurate in capturing the extraction profile of MAE (R-square value greater than 0.87). Besides, the predicted yields from the model showed good agreement with the experimental results with less than 10% deviation observed. Furthermore, suitable extraction times to ensure high extraction yield at various MAE conditions can be estimated based on absorbed microwave energy. The estimation is feasible as more than 85% of active compounds can be extracted when compared with the conventional extraction technique. Copyright © 2013 Elsevier Ltd. All rights reserved.
Extraction of functional ingredients from spinach (Spinacia oleracea L.) using liquid solvent and supercritical CO₂ extraction.
Jaime, Laura; Vázquez, Erika; Fornari, Tiziana; López-Hazas, María del Carmen; García-Risco, Mónica R; Santoyo, Susana; Reglero, Guillermo
In this work three different techniques were applied to extract dry leaves of spinach (Spinacia oleracea): solid-liquid extraction (SLE), pressurised liquid extraction (PLE) and supercritical fluid extraction (SFE) to investigate the influence of extraction solvent and technique on extracts composition and antioxidant activity. Moreover, the influence of carotenoids and phenolic compounds on the antioxidant and anti-inflammatory activities of spinach extracts was also studied. The higher concentrations of carotenoids and the lower content of phenolic compounds were observed in the supercritical CO₂ extracts; whereas water and/or ethanol PLE extracts presented low amounts of carotenoids and the higher concentrations of phenolic compounds. PLE extract with the highest content of phenolic compounds showed the highest antioxidant activity, although SFE carotenoid rich extract also showed a high antioxidant activity. Moreover, both extracts presented an important anti-inflammatory activity. PLE seems to be a good technique for the extraction of antioxidant and anti-inflammatory compounds from spinach leaves. Moreover, spinach phenolic compounds and carotenoids present a high antioxidant activity, whereas spinach carotenoids seem to show a higher anti-inflammatory activity than phenolic compounds. It is worth noting that of our knowledge this is the first time the anti-inflammatory activity of lipophilic extracts from spinach leaves is reported. © 2014 Society of Chemical Industry.
A hybrid approach for robust multilingual toponym extraction and disambiguation
Habib, Mena Badieh; van Keulen, Maurice
Toponym extraction and disambiguation are key topics recently addressed by fields of Information Extraction and Geographical Information Retrieval. Toponym extraction and disambiguation are highly dependent processes. Not only toponym extraction effectiveness affects disambiguation, but also
Caffeine adsorption of montmorillonite in coffee extracts.
Shiono, Takashi; Yamamoto, Kenichiro; Yotsumoto, Yuko; Yoshida, Aruto
The growth in health-conscious consumers continues to drive the demand for a wide variety of decaffeinated beverages. We previously developed a new technology using montmorillonite (MMT) in selective decaffeination of tea extract. This study evaluated and compared decaffeination of coffee extract using MMT and activated carbon (AC). MMT adsorbed caffeine without significant adsorption of caffeoylquinic acids (CQAs), feruloylquinic acids (FQAs), dicaffeoylquinic acids (di-CQAs), or caffeoylquinic lactones (CQLs). AC adsorbed caffeine, chlorogenic acids (CGAs) and CQLs simultaneously. The results suggested that the adsorption selectivity for caffeine in coffee extract is higher in MMT than AC. The caffeine adsorption isotherms of MMT in coffee extract fitted well to the Langmuir adsorption model. The adsorption properties in coffee extracts from the same species were comparable, regardless of roasting level and locality of growth. Our findings suggest that MMT is a useful adsorbent in the decaffeination of a wide range of coffee extracts.
New extraction chromatographic material for rhenium separation
International Nuclear Information System (INIS)
Lucanikova, M.; Czech Technical University, Prague; Kucera, J.; Czech Technical University, Prague; Sebesta, F.
Three types of the extraction chromatographic materials, composed from Aliquat R 336 deposited in the polyacrylonitrile (PAN) beads and prepared by different procedures, were compared for extraction of rhenium. The best properties were exhibited when the solid extractant was prepared by impregnation of the ready-made PAN beads. Solid extractant prepared by direct coagulation of the beads from the suspension of Aliquat R 336 in solution of PAN in nitric acid differs only by lower capacity in dynamic conditions. Material prepared from the PAN solution in dimethylsulfoxide was the worst because Aliquat R 336 was washed out from the beads during coagulation of the polymer and the extraction capacity was low. As it is shown, the first two solid extractants are fully comparable with the commercial TEVA Resin. (author)
Extraction of scandium by organic substance melts
International Nuclear Information System (INIS)
Gladyshev, V.P.; Lobanov, F.I.; Zebreva, A.I.; Andreeva, N.N.; Manuilova, O.A.; Il'yukevich, Yu.A.
Regularities of scandium extraction by the melts of octadecanicoic acid, n-carbonic acids of C 17 -C 20 commerical fraction and mixtures of tributylphosphate (TBP) with paraffin at (70+-1) deg C have been studied. The optimum conditions for scandium extraction in the melt of organic substances are determined. A scheme of the extraction by the melts of higher carbonic acids at ninitial metal concentrations of 10 -5 to 10 -3 mol/l has been suggested. The scandium compound has been isolated in solid form, its composition having been determined. The main advantages of extraction by melts are as follows: a possibility to attain high distribution coefficients, distinct separation of phases after extraction, the absence of emulsions, elimination of employing inflammable and toxic solvents, a possibility of rapid X-ray fluorescence determinatinon of scandium directly in solid extract
Extraction of fluoride metal complexes by octanols
International Nuclear Information System (INIS)
Baklanova, I.V.; Nikolaev, A.I.; Il'in, E.G.; Majorov, V.G.
The extraction of niobium(V) and tantalum(V) by octanols, including 1-octanol, 2-octanol, and iso-octanol (2-ethylhexanol), was studied. The composition of the octanols and their solubility in various aqueous solutions were evaluated. The capacity of the octanols for tantalum(V) and niobium(V), the extraction properties of the octanols, the viscosity of extracts under conditions of metal fluoride extraction, and the temperature dependence of the viscosity of the octanols were studied. The composition of the extracted complexes was studied by IR and NMR spectroscopy and chemical analysis, and the hydration-solvation mechanism of the extraction of tantalum(V) and niobium(V) was supported [ru
Recent solvent extraction experience at Savannah River
International Nuclear Information System (INIS)
Gray, L.W.; Burney, G.A.; Gray, J.H.; Hodges, M.E.; Holt, D.L.; Macafee, I.M.; Reif, D.J.; Shook, H.E.
Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes
Extraction of scandium by aromatic carboxylic acids
International Nuclear Information System (INIS)
Kamenev, V.F.; Fadeeva, V.I.
Extraction of complex compounds af scandium with salicylic, phenyl- and diphenylacetic acids with chloroform solutions of tetraethyldiamideheptylphosphate as a donor-active additive in relation to the pH and reagent concentration has been studied. Extraction of salicylates of some elements (Ta, Nb, Zr, Hf, Mo) by solutions of tetraethyldiamideheptylphosphate in chloroform has been investigated, and the possibility of their extraction separation from scandium is shown
Resource Extraction in a Political Economy Framework
Ryszka, Karolina
We analyze resource extraction in a political economy setting by introducing a political leader who optimizes both his own and the society's welfare function. We find that accounting for the private utility of a political elite, its higher discount rate and a different time horizon generally speeds up extraction. The higher than optimal resource extraction is not only relevant in welfare terms, but also regarding possible consequences with respect to climate change. The effect of higher extra...
Extraction chromatography of lanthanides, ch. 8
International Nuclear Information System (INIS)
Siekierski, S.; Fidelis, I.
The extraction of lanthanides by chelate formation with acidic organophosphorous extractants, by solvation of salts, and in the form of ion pairs is reviewed. The double-double effect and its significance for the lanthanide as well as the actinide separation is discussed. A short survey of the existing data on the enthalpies of lanthanide extraction and on the influence of temperature on their separation factor is given. The resolution ability of columns used for the separation of lanthanides is briefly surveyed
Supercritical solvent extraction of oil sand bitumen
Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.
The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.
Investigations on bark extracts of Picea abies
Energy Technology Data Exchange (ETDEWEB)
Weissmann, G
Successive extraction of the bark with solvents of increasing polarity yielded about 60% of soluble material. The alcohol and water extracts contained principally simple polyphenols and their glycosides, tannins, mono-and disaccharides, soluble hemicelluloses and pectins. Hot water extracts are suitable for production of adhesives by reaction with formaldehyde, but their polyphenol content is only 50%. The polyphenols and their glycosides, and glucosides of hydroxystilbenes, were investigated in detail.
Combined transuranic-strontium extraction process
Horwitz, E. Philip; Dietz, Mark L.
The transuranic (TRU) elements neptunium, plutonium and americium can be separated together with strontium from nitric acid waste solutions in a single process. An extractant solution of a crown ether and an alkyl(phenyl)-N,N-dialkylcarbanylmethylphosphine oxide in an appropriate diluent will extract the TRU's together with strontium, uranium and technetium. The TRU's and the strontium can then be selectively stripped from the extractant for disposal.
Biosynthesis of silver nanoparticles using Stevia extracts
International Nuclear Information System (INIS)
Laguta, I.V.; Fesenko, T.V.; Stavinskaya, O.N.; Shpak, L.M.; Dzyuba, O.I.
Silver nanoparticles are synthesized using Stevia rebaudiana extracts. It is shown that the rate of nanoparticles formation is affected by plant cultivation conditions. It is found that, in the presence of the extract from callus, the formation of nanoparticles occurs faster than in the presence of extracts from plants grown under conditions of ex situ and in vitro. The synthesized silver nanoparticles were studied by UV and IR spectroscopies
Binary Solvent Extraction System and Extraction Time Effects on Phenolic Antioxidants from Kenaf Seeds (Hibiscus cannabinus L.) Extracted by a Pulsed Ultrasonic-Assisted Extraction
Yu Hua Wong; Hwee Wen Lau; Chin Ping Tan; Kamariah Long; Kar Lin Nyam
The aim of this study was to determine the best parameter for extracting phenolic-enriched kenaf (Hibiscus cannabinus L.) seeds by a pulsed ultrasonic-assisted extraction. The antioxidant activities of ultrasonic-assisted kenaf seed extracts (KSE) were determined by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, β -carotene bleaching inhibition assay, and ferric reducing antioxi...
Extraction and Characterization of Cottonseed (Gossypium) Oil
Efomah Andrew Ndudi; Orhevba Bosede Adelola
This study investigated the extraction and characterization of cottonseed oil using solvent extraction method. Normal hexane was used as solvent in the extraction process. The AOAC method of Analysis was employed in the determination of the chemical, physical and proximate compositions of the oil. The chemical properties of the oil determined include the saponification value, free fatty acid, iodine value, peroxide value and acid value. The physical properties of the oil determined are viscos...
Extraction of scandium by aromatic carboxylic acids
Energy Technology Data Exchange (ETDEWEB)
Kamenev, V F; Fadeeva, V I [Moskovskij Gosudarstvennyj Univ. (USSR)
Extraction of complex compounds af scandium with salicylic, phenyl- and diphenylacetic acids with chloroform solutions of tetraethyldiamideheptylphosphate as a donor-active additive in relation to the pH and reagent concentration has been studied. Extraction of salicylates of some elements (Ta, Nb, Zr, Hf, Mo) by solutions of tetraethyldiamideheptylphosphate in chloroform has been investigated, and the possibility of their extraction separation from scandium is shown.
Rules Extraction with an Immune Algorithm
Directory of Open Access Journals (Sweden)
Deqin Yan
Full Text Available In this paper, a method of extracting rules with immune algorithms from information systems is proposed. Designing an immune algorithm is based on a sharing mechanism to extract rules. The principle of sharing and competing resources in the sharing mechanism is consistent with the relationship of sharing and rivalry among rules. In order to extract rules efficiently, a new concept of flexible confidence and rule measurement is introduced. Experiments demonstrate that the proposed method is effective.
Comparative Neuropharmacological Activities Methanolic Extracts of ...
African Journals Online (AJOL)
Comparative neuropharmacological efficacy of the leaf and root 70 % methanol extract of Cissus cornifolia was studied in mice. The extractive values of the leaf and root methanol extract was found to be 31.5 g with yield of 12.6 %(w/w) and 37.8 g with the yield of 15.12 %(w/w) respectively. The acute toxicity (LD50) values ...
Zingiber officinale Roscoe aqueous extract modulates ...
African Journals Online (AJOL)
Zingiber officinale Roscoe aqueous extract modulates Matrixmetalloproteinases and tissue inhibitors of Metalloproteinases expressions in Dengue virus-infected cells: implications for prevention of vascular permeability.
Saw palmetto ethanol extract inhibits adipocyte differentiation.
Villaverde, Nicole; Galvis, Adriana; Marcano, Adriana; Priestap, Horacio A; Bennett, Bradley C; Barbieri, M Alejandro
The fruits of saw palmetto have been used for the treatment of a variety of urinary and reproductive system problems. In this study we investigated whether the fruit extracts affect in vitro adipogenesis. Saw palmetto ethanol extract inhibited the lipid droplet accumulation by induction media in a dose-dependent manner, and it also attenuated the protein expressions of C-EBPα and PPARγ. Phosphorylation of Erk1/2 and Akt1 were also decreased by saw palmetto ethanol extract. This report suggests that saw palmetto extracts selectively affect the adipocyte differentiation through the modulation of several key factors that play a critical role during adipogenesis.
Metal extraction by amides of carboxylic acids
International Nuclear Information System (INIS)
Skorovarov, D.I.; Chumakova, G.M.; Rusin, L.I.; Ul'anov, V.S.; Sviridova, R.A.; Sviridov, A.L.
Extraction ability of various amides was studied. Data on extraction of rare earths, vanadium, molybdenum, rhenium, uranium, niobium, tantalum by N,N-dibutyl-amides of acetic, nonanic acids and fatly synthetic acids of C 7 -C 9 fractions are presented. Effect of salting-out agents, inorganic acid concentrations on extraction process was studied. Potential ability of using amides of carboxylic acids for extractional concentration of rare earths as well as for recovery and separation of iron, rhenium, vanadium, molybdenum, uranium, niobium, and tantalum was shown
Light extraction block with curved surface
Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.
Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.
Cytotoxic Effects of Bangladeshi Medicinal Plant Extracts
Directory of Open Access Journals (Sweden)
Shaikh J. Uddin
Full Text Available To investigate the cytotoxic effect of some Bangladeshi medicinal plant extracts, 16 Bangladeshi medicinal plants were successively extracted with n-hexane, dichloromethane, methanol and water. The methanolic and aqueous extracts were screened for cytotoxic activity against healthy mouse fibroblasts (NIH3T3 and three human cancer-cell lines (gastric: AGS; colon: HT-29; and breast: MDA-MB-435S using the MTT assay. Two methanolic extracts (Hygrophila auriculata and Hibiscus tiliaceous and one aqueous extract (Limnophila indica showed no toxicity against healthy mouse fibroblasts, but selective cytotoxicity against breast cancer cells (IC50 1.1–1.6 mg mL−1. Seven methanolic extracts from L. indica, Clerodendron inerme, Cynometra ramiflora, Xylocarpus moluccensis, Argemone mexicana, Ammannia baccifera and Acrostichum aureum and four aqueous extracts from Hygrophila auriculata, Bruguiera gymnorrhiza, X. moluccensis and Aegiceras corniculatum showed low toxicity (IC50 > 2.5 mg mL−1 against mouse fibroblasts but selective cytotoxicity (IC50 0.2–2.3 mg mL−1 against different cancer cell lines. The methanolic extract of Blumea lacera showed the highest cytotoxicity (IC50 0.01–0.08 mg mL−1 against all tested cell lines among all extracts tested in this study. For some of the plants their traditional use as anticancer treatments correlates with the cytotoxic results, whereas for others so far unknown cytotoxic activities were identified.
Methanol Extract of Myelophycus caespitosus Inhibits the ...
African Journals Online (AJOL)
Methanol Extract of Myelophycus caespitosus Inhibits the Inflammatory Response in Lipopolysaccharidestimulated BV2 Microglial Cells by Downregulating NF-kB via Inhibition of the Akt Signaling Pathway.
A novel perspective on pectin extraction
DEFF Research Database (Denmark)
Dominiak, Malgorzata Maria
optimization is a long process because the evaluation of the final product quality is accomplished at the end of the procedure, employing time-consuming off-line laboratory tests. Fourier transform infrared spectroscopy (FTIR) and carbohydrate microarrays, combined with chemometrics, were evaluated...... determined the optimal extraction time for both the enzymatic and acidic extraction processes. The combined results suggested major differences in the crude pectin extract traits of enzymatically vs. acidically extracted pectin with respect to the degree of esterification, purity, and abundance...
Ge extraction from gasification fly ash
Energy Technology Data Exchange (ETDEWEB)
Oriol Font; Xavier Querol; Angel Lopez-Soler; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)
Water-soluble germanium species (GeS{sub 2}, GeS and hexagonal-GeO{sub 2}) are generated during coal gasification and retained in fly ash. This fact together with the high market value of this element and the relatively high contents in the fly ashes of the Puertollano Integrated Gasification in Combined Cycle (IGCC) plant directed our research towards the development of an extraction process for this element. Major objectives of this research was to find a low cost and environmentally suitable process. Several water based extraction tests were carried out using different Puertollano IGCC fly ash samples, under different temperatures, water/fly ash ratios, and extraction times. High Ge extraction yields (up to 84%) were obtained at room temperature (25{sup o}C) but also high proportions of other trace elements (impurities) were simultaneously extracted. Increasing the extraction temperature to 50, 90 and 150{sup o}C, Ge extraction yields were kept at similar levels, while reducing the content of impurities, the water/fly ash ratio and extraction time. The experimental data point out the influence of chloride, calcium and sulphide dissolutions on the Ge extraction. 16 refs., 9 figs., 6 tabs.
Extraction of radioactive cesium from tea leaves
International Nuclear Information System (INIS)
Yano, Yukiko; Kubo, M. Kenya; Higaki, Shogo; Hirota, Masahiro; Nomura, Kiyoshi
Radioactive contamination of foodstuffs attributed to the Fukushima Daiichi nuclear disaster has become a social problem. This study investigated the extraction of radioactive cesium from the contaminated leaves to the tea. The green tea was brewed twice reusing the same leaves to study the difference in extraction of cesium between the first and second brew. Moreover, the extraction of cesium was studied in correlation to brewing time. The concentration of radioactive cesium was determined with gamma spectrometry, and the concentration of caffeine was determined with absorption spectrometry. About 40% of cesium was extracted from leaves in the first brew, and about 80% was extracted in the second brew. The extraction of cesium increased over time, and it reached about 80% after 10 minutes brew. The ratio of radioactive cesium to caffeine decreased linearly over time. This study revealed that the extraction of cesium was higher for the second brew, and a rapid increase in extraction was seen as the tea was brewed for 6 minutes and more. Therefore, the first brew of green tea, which was brewed within 5 minutes, contained the least extraction of radioactive cesium from the contaminated leaves. (author)
Extraction of scandium salicylate by tetraethyldiamidoheptyl phosphate
Energy Technology Data Exchange (ETDEWEB)
Kamenev, V F; Fadeeva, V I; Zyk, N V [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Analiticheskoj Khimii
Scandium salicylate is extracted with chloroform in a narrow pH range 3-4 and at the maximum concentration of salicylic acid (H/sub 2/A) in an organic phase, the distribution coefficient reaches 0.1. In the presence of tetraethyldiamideheptylphosphate (DAHP) the zone of maximum extraction grows and the distribution coefficient increases. The ratio of the components in the complex extracted is Sc:H/sub 2/A:DAHPh=1:3:2. The extraction constant is Ksub(ex)=(2.00+-0.02).
Significance of wood extractives for wood bonding.
Roffael, Edmone
Wood contains primary extractives, which are present in all woods, and secondary extractives, which are confined in certain wood species. Extractives in wood play a major role in wood-bonding processes, as they can contribute to or determine the bonding relevant properties of wood such as acidity and wettability. Therefore, extractives play an immanent role in bonding of wood chips and wood fibres with common synthetic adhesives such as urea-formaldehyde-resins (UF-resins) and phenol-formaldehyde-resins (PF-resins). Extractives of high acidity accelerate the curing of acid curing UF-resins and decelerate bonding with alkaline hardening PF-resins. Water-soluble extractives like free sugars are detrimental for bonding of wood with cement. Polyphenolic extractives (tannins) can be used as a binder in the wood-based industry. Additionally, extractives in wood can react with formaldehyde and reduce the formaldehyde emission of wood-based panels. Moreover, some wood extractives are volatile organic compounds (VOC) and insofar also relevant to the emission of VOC from wood and wood-based panels.
Extraction of Rose Bengal into chloroform
International Nuclear Information System (INIS)
Lengyel, J.; Vecernik, J.; Krtil, J.
The paper describes the extraction of Rose Bengal (RB)into chloroform. A radiometric method with the aid of 131 Ilabelled RB was used. The efficiency of the extraction in dependence on pH and RB concentration was studied. For the interpretation of the extraction data the values of pK 1 and pK 2 of RB were determined spectrophotometrical-ly and potentiometrically. A mechanism for the RB extraction into chloroform on the basis of IR measurements is proposed. (author)
Parameter extraction with neural networks
Cazzanti, Luca; Khan, Mumit; Cerrina, Franco
In semiconductor processing, the modeling of the process is becoming more and more important. While the ultimate goal is that of developing a set of tools for designing a complete process (Technology CAD), it is also necessary to have modules to simulate the various technologies and, in particular, to optimize specific steps. This need is particularly acute in lithography, where the continuous decrease in CD forces the technologies to operate near their limits. In the development of a 'model' for a physical process, we face several levels of challenges. First, it is necessary to develop a 'physical model,' i.e. a rational description of the process itself on the basis of know physical laws. Second, we need an 'algorithmic model' to represent in a virtual environment the behavior of the 'physical model.' After a 'complete' model has been developed and verified, it becomes possible to do performance analysis. In many cases the input parameters are poorly known or not accessible directly to experiment. It would be extremely useful to obtain the values of these 'hidden' parameters from experimental results by comparing model to data. This is particularly severe, because the complexity and costs associated with semiconductor processing make a simple 'trial-and-error' approach infeasible and cost- inefficient. Even when computer models of the process already exists, obtaining data through simulations may be time consuming. Neural networks (NN) are powerful computational tools to predict the behavior of a system from an existing data set. They are able to adaptively 'learn' input/output mappings and to act as universal function approximators. In this paper we use artificial neural networks to build a mapping from the input parameters of the process to output parameters which are indicative of the performance of the process. Once the NN has been 'trained,' it is also possible to observe the process 'in reverse,' and to extract the values of the inputs which yield outputs
Comparative exergy analyses of Jatropha curcas oil extraction methods: Solvent and mechanical extraction processes
International Nuclear Information System (INIS)
Ofori-Boateng, Cynthia; Keat Teong, Lee; JitKang, Lim
Highlights: ► Exergy analysis detects locations of resource degradation within a process. ► Solvent extraction is six times exergetically destructive than mechanical extraction. ► Mechanical extraction of jatropha oil is 95.93% exergetically efficient. ► Solvent extraction of jatropha oil is 79.35% exergetically efficient. ► Exergy analysis of oil extraction processes allow room for improvements. - Abstract: Vegetable oil extraction processes are found to be energy intensive. Thermodynamically, any energy intensive process is considered to degrade the most useful part of energy that is available to produce work. This study uses literature values to compare the efficiencies and degradation of the useful energy within Jatropha curcas oil during oil extraction taking into account solvent and mechanical extraction methods. According to this study, J. curcas seeds on processing into J. curcas oil is upgraded with mechanical extraction but degraded with solvent extraction processes. For mechanical extraction, the total internal exergy destroyed is 3006 MJ which is about six times less than that for solvent extraction (18,072 MJ) for 1 ton J. curcas oil produced. The pretreatment processes of the J. curcas seeds recorded a total internal exergy destructions of 5768 MJ accounting for 24% of the total internal exergy destroyed for solvent extraction processes and 66% for mechanical extraction. The exergetic efficiencies recorded are 79.35% and 95.93% for solvent and mechanical extraction processes of J. curcas oil respectively. Hence, mechanical oil extraction processes are exergetically efficient than solvent extraction processes. Possible improvement methods are also elaborated in this study.
Directory of Open Access Journals (Sweden)
W. Silva
Full Text Available ABSTRACT This study aims to obtain an extract from red wine by using membrane-based supercritical fluid extraction. This technique involves the use of porous membranes as contactors during the dense gas extraction process from liquid matrices. In this work, a Cabernet Sauvignon wine extract was obtained from supercritical fluid extraction using pressurized carbon dioxide as solvent and a hollow fiber contactor as extraction setup. The process was continuously conducted at pressures between 12 and 18 MPa and temperatures ranged from 30 to 50ºC. Meanwhile, flow rates of feed wine and supercritical CO2 varied from 0.1 to 0.5 mL min-1 and from 60 to 80 mL min-1 (NCPT, respectively. From extraction assays, the highest extraction percentage value obtained from the total amount of phenolic compounds was 14% in only one extraction step at 18MPa and 35ºC. A summarized chemical characterization of the obtained extract is reported in this work; one of the main compounds in this extract could be a low molecular weight organic acid with aromatic structure and methyl and carboxyl groups. Finally, this preliminary characterization of this extract shows a remarkable ORAC value equal to 101737 ± 5324 µmol Trolox equivalents (TE per 100 g of extract.
Language extraction from zinc sulfide
Varn, Dowman Parks
Recent advances in the analysis of one-dimensional temporal and spacial series allow for detailed characterization of disorder and computation in physical systems. One such system that has defied theoretical understanding since its discovery in 1912 is polytypism. Polytypes are layered compounds, exhibiting crystallinity in two dimensions, yet having complicated stacking sequences in the third direction. They can show both ordered and disordered sequences, sometimes each in the same specimen. We demonstrate a method for extracting two-layer correlation information from ZnS diffraction patterns and employ a novel technique for epsilon-machine reconstruction. We solve a long-standing problem---that of determining structural information for disordered materials from their diffraction patterns---for this special class of disorder. Our solution offers the most complete possible statistical description of the disorder. Furthermore, from our reconstructed epsilon-machines we find the effective range of the interlayer interaction in these materials, as well as the configurational energy of both ordered and disordered specimens. Finally, we can determine the 'language' (in terms of the Chomsky Hierarchy) these small rocks speak, and we find that regular languages are sufficient to describe them.
Thornton, J.D.
This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.
Directory of Open Access Journals (Sweden)
Vladimir Pfeifer
Full Text Available Background. Ectopia lentis continues to be a therapeutic challenge for ophthalmologists. It can occur as an isolated condition, after ocular trauma, in association with other ocular disorders, as part of a systemic mesodermal disease or a complication of general metabolic disorders. Minimal subluxation of the lens may cause no visual symptoms, but in more advanced cases serious optical disturbances arise. The most important is amblyopia. Surgical treatment options include iris manipulation, lens discission, aspiration, intracapsular or extracapsular extraction, and pars plana lensectomy. The choice of surgical technique remains controversial, in part because of the historically poor visual results and high rate of perioperative complications, including vitreous loss and retinal detachment.Methods. We describe a surgical technique based on the use of the Cionni endocapsular tension ring, dry irrigation aspiration of lens material, centration of the capsular bag and foldable intraocular lens implantation into the bag. With mentioned surgical technique 8 patients were operated; 4 boys and 4 girls, together 11 eyes.Results. The final BCVA after follow up period improved in 9 eyes and it remained the same as before operation in one eye. Statistical comparison of preoperative and postoperative visual acuities showed significant improvement. On the other hand there was no correlation between preoperative and postoperative visual acuity.Conclusions. This surgical procedure is an alternative approach in solving this challenging cases of ectopia lentis with good postoperative visual rehabilitation.
Extraction of Tetravalent Uranium by Certain Acidic Organophosphorus Extractants from Phosphate Medium
International Nuclear Information System (INIS)
Daoud, J.A.; Zeid, M.M.; Aly, H.F.
The extraction of U(IV) by octylphenyl acid phosphate (OPAP) or di-2-ethylhexyl phosphoric acid (HDEHP) in kerosene from phosphoric acid was carried out. The effect of extractant, phosphoric acid, uranium, Fe(II) and Fe(III) concentration on the extraction process was separately investigated. The effect of different reagents and temperature on the stripping of U(IV) was also investigated. The results obtained for the extraction of U(IV) by HDEHP showed that the extraction with the increase in HDEHP and Fe(III) concentration while it decreases with the increase in phosphoric acid, uranium and Fe(II) concentration. In case of extraction with OPAP, the extraction of U(IV) was found to decrease with the phosphoric acid, Fe(II) and initial uranium concentration while the increase in OPAP concentration slightly affected the extraction. The use of high phosphoric acid concentration as stripper at low temperature was found to give the best stripping results
Quantification of allyl hexanoate in pineapple beverages and yogurts as a case study to characterise a source of uncertainty in dietary exposure assessment to flavouring substances.
Raffo, A; D'Aloise, A; Magrì, A D; Leclercq, C
One source of uncertainty in the estimation of dietary exposure to flavouring substances is the uncertainty in the occurrence and concentration levels of these substances naturally present or added to foodstuffs. The aim of this study was to assess the variability of concentration levels of allyl hexanoate, considered as a case study, in two main food categories to which it is often added: pineapple juice-based beverages and yogurts containing pineapple. Thirty-four beverages and 29 yogurts, with pineapple fruit or juice and added flavourings declared as ingredients on the package, were purchased from the local market (in Rome) and analysed. Analytical methods based on the stir bar sorptive extraction (SBSE) technique for the isolation of the target analyte, and on GC-MS analysis for final determination, were developed for the two food categories. In beverages, allyl hexanoate concentrations ranged from less than 0.01 to 16.71 mg l(-1), whereas in yogurts they ranged from 0.02 to 89.41 mg kg(-1). Average concentrations in beverages and yogurts with pineapple as the main fruit ingredient (1.91 mg l(-1) for beverages, 9.61 mg kg(-1) for yogurts) were in fair agreement with average use level data reported from industry surveys for the relevant food categories (4.5 and 6.0 mg kg(-1), respectively). Within the group of yogurts a single product was found to contain a level of allyl hexanoate more than 10-fold higher than the average reported use level. The screening techniques developed by the European Food Safety Authority (EFSA) using use level data provided by industry gave estimates of exposure that were of the same order of magnitude as the estimates obtained for regular consumers who would be loyal to the pineapple yogurt and beverage products containing the highest observed concentration of the substance of interest. In this specific case the uncertainty in the results obtained with the use of standard screening techniques for exposure assessment based on industry
Effective extractants for the extraction of lithium from aqueous solutions containing sodium and potassium compounds
International Nuclear Information System (INIS)
Marinkina, G.A.; Zanina, A.S.; Shergina, S.I.; Sokolov, I.E.; Kotlyarevskii, I.L.
The extraction power of newly obtained pure methoxy-1,3-diketones in diluents and in their mixtures with electron-donating additives during the extraction of lithium from aqueous solutions containing sodium and potassium was investigated. High separation factors were obtained; no appreciable amounts of sodium and potassium were found in the extract after total extraction of the lithium. 9 refs., 2 figs., 8 tabs
Sustainable extraction of molecules for human food, cosmetic and pharmaceutical products: extraction in supercritical fluids
International Nuclear Information System (INIS)
Leone, GianPaolo; Ferri, Donatella
Since several years, the ENEA Innovation Laboratory for Agro-Industrial, proposed activities of research and development of extraction processes with supercritical fluids (SFE, Supercritical Fluid Extraction), focusing on sustainability characteristics of the process. The technique, in fact, makes no use of organic solvents, has a low energy consumption and requires a lower number of process steps compared to conventional extractions. The process also responds to the requirements imposed by the legislation for human food, cosmetic and pharmaceutical extracts. [it
Sustainable extraction of molecules for potable alcohol, cosmetics and pharmaceuticals: extraction in supercritical fluids
International Nuclear Information System (INIS)
Leone, Gian Paolo; Ferri, Donatella
Since many years the Laboratory of Agro-Industrial Innovation (UTAGRI-INN) ENEA proposed research and development of extraction processes with supercritical fluids (SFE, Supercritical Fluid Extraction), aiming on the sustainability of the process characteristics. The technique, in fact, makes no use of organic solvents, It has reduced energy consumption and requires a number of process step lower than the extractions traditional. The process also responds to the requirements required by the regulations for food use, cosmetics and pharmaceutical extracts. [it
leaves extract on mild steel in acid
African Journals Online (AJOL)
The volume of the cathodic hydrogen gas evolved was also plotted as a .... prevent the escape of hydrogen gas. The volume .... Clivia nobilis leaves extract on the flow of current ... behaviour of ethanol extract of Piper guinensis as a green ...
Antifungal activity of olive cake extracts
Ghandi H. Anfoka; Khalil I. Al-Mughrabi; Talal A. Aburaj; Wesam Shahrour
Powdered, dried olive (Olea europaea) cake was extracted with hexane, methanol and butanol. Six phenolic compounds, coumaric acid, ferulic acid, oleuropein, caffeic acid, protocatechuic acid and cinnamic acid, were isolated from these extracts after fractionation. The fractions were tested for their antifungal activity against Verticillium sp., Fusarium oxysporum, Rhizopus sp., Penicillium italicum, Rhizoctonia solani, Stemphylium solani, Cladosporium sp., Mucor sp., Colletotrichu...
21 CFR 73.30 - Annatto extract.
... fats. The alkaline alcohol or aqueous extracts may be treated with food-grade acids to precipitate..., methyl alcohol, methylene chloride, trichloroethylene. (2) Color additive mixtures for food use made with... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Annatto extract. 73.30 Section 73.30 Food and...
Automated extraction of DNA from clothing
DEFF Research Database (Denmark)
Stangegaard, Michael; Hjort, Benjamin Benn; Nøhr Hansen, Thomas
Presence of PCR inhibitors in extracted DNA may interfere with the subsequent quantification and short tandem repeat (STR) reactions used in forensic genetic DNA typing. We have compared three automated DNA extraction methods based on magnetic beads with a manual method with the aim of reducing...
Batch extractive distillation for high purity methanol
International Nuclear Information System (INIS)
Zhang Weijiang; Ma Sisi
In this paper, the application in chemical industry and microelectronic industry, market status and the present situation of production of high purity methanol at home and abroad were introduced firstly. Purification of industrial methanol for high purity methanol is feasible in china. Batch extractive distillation is the best separation technique for purification of industrial methanol. Dimethyl sulfoxide was better as an extractant. (authors)
Fingerprint Minutiae Extraction using Deep Learning
CSIR Research Space (South Africa)
Darlow, Luke Nicholas
Full Text Available components, such as image enhancement. We pose minutiae extraction as a machine learning problem and propose a deep neural network – MENet, for Minutiae Extraction Network – to learn a data-driven representation of minutiae points. By using the existing...
Ion Beam Extraction by Discrete Ion Focusing
DEFF Research Database (Denmark)
An apparatus (900) and methods are disclosed for ion beam extraction. In an implementation, the apparatus includes a plasma source (or plasma) (802) and an ion extractor (804). The plasma source is adapted to generate ions and the ion extractor is immersed in the plasma source to extract a fracti...
( Asteraceae ) methanol extracts against Helicobacter pylori
African Journals Online (AJOL)
Methanol vehicle did not affect H. pylori growth. Conclusion: The observed antibacterial effect of G. glutinosum extracts may be of benefit as an adjuvant treatment of diseases caused by H. pylori. Key words: Gymnosperma glutinosum, Helicobacter pylori, methanol extract, minimal inhibitory concentration (MIC).
Idioms-based Business Rule Extraction
R Smit (Rob)
htmlabstractThis thesis studies the extraction of embedded business rules, using the idioms of the used framework to identify them. Embedded business rules exist as source code in the software system and knowledge about them may get lost. Extraction of those business rules could make them accessible
Immunostimulant activity of standardised extracts of Mangifera ...
African Journals Online (AJOL)
Purpose: To investigate the immunomodulating activity of Mangifera indica. (MI) and Curcuma domestica (CD) extracts in mice. Methods: Mice were randomly divided into 4 groups, namely, vehicle, untreated, MI and CD groups (n = 6). They were treated with MI (160 mg/kg) or CD (200 mg/kg) extracts, and vehicle for control ...
Gold and Silver Extraction from Leach Solutions
Bagdaulet K. Kenzhaliyev; Renata R. Iskhakova; Zamzagul D. Dosymbaeva; Esen N. Sulejmenov
There has been carried out an investigation on the extraction of gold and silver from thiosulfate solutions: standard test and technological solutions of chemical and electrochemical leaching. The influence of related metals on the process of extracting gold from solution was studied. There has been conducted a comparative study of the IR spectra of solutions after the sorption of gold, silver and related metals.
Mastering aesthetics in post-extraction sites
Goené, R.J.; van Daelen, A.C.L.
Patients increasingly seek implant-supported restorations that can be delivered as quickly and non-invasively as possible. Many also prefer to avoid wearing a removable prothesis after tooth extraction. Implants that are placed immediately in fresh extraction sockets and provisionalized immediately
Extraction, Isolation And Characterization Of Bioactive Compounds ...
African Journals Online (AJOL)
Natural products from medicinal plants, either as pure compounds or as standardized extracts, provide unlimited opportunities for new drug leads because of the ... The analysis of bioactive compounds present in the plant extracts involving the applications of common phytochemical screening assays, chromatographic ...
The extractives of Pinus pinaster wood
Richard W. Hemingway; W. E. Hillis; L. S. Lau
The extractives in Pinus pinaster wood grown in South Australia were examined as part of an assessment of the suitability of this wood for manufacture of absorbent tissues from bisulphite pulps. The average petroleum solubility of the wood was 2.0% but the amount and composition of the petroleum extract varied widely depending upon the age of the...
Extraction of molybdenum VI by alpha benzoinoxime
International Nuclear Information System (INIS)
Achache, M.; Meklati, M.
The concentration of molybdenum, was studied using alpha benzoinoxime dissolved in chloroform. Several acids and salt at different levels of concentration were investigated as well as other parameters such as (mixing time, extractant to metal ratio, temperature etc.) The molybdenum stippling was also studied in alkaline medium with the subsequent recovery of the extractant and solvent
Extraction optimization and characterization of polysaccharide ...
African Journals Online (AJOL)
Purpose: To investigate the optimum extraction conditions of polysaccharides from Pinellia Rhizoma (PRP) and their antioxidant activities. Methods: Response surface methodology (RSM) was applied to optimize the water extraction conditions of PRP by Box-Benhnken design (BBD). A high performance liquid ...
Lipase and protease extraction from activated sludge
DEFF Research Database (Denmark)
Gessesse, Amare; Dueholm, Thomas; Petersen, Steffen B.
of gentle and efficient enzyme extraction methods from environmental samples is very important. In this study we present a method for the extraction of lipases and proteases from activated sludge using the non-ionic detergent Triton X-100, EDTA, and cation exchange resin (CER), alone or in combination...
Comparative antitrypanosomal screening of methanolic extracts of ...
African Journals Online (AJOL)
The in vitro and in vivo activities of methanolic extracts of defatted leaves and stems of Khaya senegalensis and Moringa oleifera on Trypanosoma brucei brucei were investigated and compared. The in vitro assessment involved incubating the parasite (in triplicate) in the presence of various extract concentrations in a ...
African Journals Online (AJOL)
Oct 4, 2016 ... methanol extract CM is a good adsorption inhibitor for the corrosion of Al-Si-Mg in 3.5wt% NaCl solution. Tafel polarization analysis indicates that the studied plant extract is a mixed ..... (2008). [2] Shreir, L. L., Jarman, R. A. and Burstein, G. T.. Corrosion ... [6] Maqsood Ahmad Malik, Mohammad Ali Hashim,.
Data extraction from proteomics raw data
DEFF Research Database (Denmark)
Mancuso, Francesco; Bunkenborg, Jakob; Wierer, Michael
In shot-gun proteomics raw tandem MS data are processed with extraction tools to produce condensed peak lists that can be uploaded to database search engines. Many extraction tools are available but to our knowledge, a systematic comparison of such tools has not yet been carried out. Using raw data...
Leaf Extract Of Anacardium occidentale on Gastric
African Journals Online (AJOL)
Chigo Okwuosa
Keywords; Anacardium occidentale, aqueous extract, gastric acid secretion, rats, intragastric. *Address for correspondence: . email@example.com. Revised version accepted: March 2010. INTRODUCTION. The plant, Anacardium occidentale. L belongs to the. Family; Anacardiaceae. It is popularly called cashew. Extracts ...
Chattopadhyay, R.R.
The anxiolytic activity of Ocimum sanctum leaf extract was studied in mice. O.sanctum leaf extract produced significant anxiolytic activity in plus – maze and open field behaviour test models. The effect was compared with diazepam, a standard antianxiety drug.
Reactive extraction of lactic acid using alamine
Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.
Lactic acid is an important commercial product and extracting it out of aqueous solution is a growing requirement in fermentation based industries and recovery from waste streams. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid–amine (solvent)
DNA Extraction Techniques for Use in Education
Hearn, R. P.; Arblaster, K. E.
DNA extraction provides a hands-on introduction to DNA and enables students to gain real life experience and practical knowledge of DNA. Students gain a sense of ownership and are more enthusiastic when they use their own DNA. A cost effective, simple protocol for DNA extraction and visualization was devised. Buccal mucosal epithelia provide a…
Anethum Graveolens Linn (Umbelliferae) Extract Attenuates Stress ...
African Journals Online (AJOL)
Anethum Graveolens Linn (Umbelliferae) Extract Attenuates Stress-induced Urinary Biochemical Changes and Improves Cognition in Scopolamineinduced Amnesic Rats. ... Conclusion: The aqueous extract of A. graveolens exhibited significant anti-stress, antioxidant and memory enhancing activities. The study provides a ...
Recent patents on the extraction of carotenoids.
Riggi, Ezio
This article reviews the patents that have been presented during the last decade related to the extraction of carotenoids from various forms of organic matter (fruit, vegetables, animals), with an emphasis on the methods and mechanisms exploited by these technologies, and on technical solutions for the practical problems related to these technologies. I present and classify 29 methods related to the extraction processes (physical, mechanical, chemical, and enzymatic). The large number of processes for extraction by means of supercritical fluids and the growing number of large-scale industrial plants suggest a positive trend towards using this technique that is currently slowed by its cost. This trend should be reinforced by growing restrictions imposed on the use of most organic solvents for extraction of food products and by increasingly strict waste management regulations that are indirectly promoting the use of extraction processes that leave the residual (post-extraction) matrix substantially free from solvents and compounds that must subsequently be removed or treated. None of the reviewed approaches is the best answer for every extractable compound and source, so each should be considered as one of several alternatives, including the use of a combination of extraction approaches.
Bibliography of extraction chromatography, ch. 15
International Nuclear Information System (INIS)
Eschrich, H.; Drent, W.
A bibliography of reviews, books and publications dealing with laminar extraction chromatography is given. A tabular survey of experimental data on column extraction chromatographic investigations, stationary phases and support materials is presented. An author index and corporative author index are included. This bibliography refers to various publications relevant to nuclear interest
Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils
Lau, E. V.; Gan, S.; Ng, H. K.
This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction. PMID:20396670
Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils
Directory of Open Access Journals (Sweden)
E. V. Lau
Full Text Available This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.
Indium extraction by an acidic extractant associated or not with synergetic agents: importance of inorganic anions
International Nuclear Information System (INIS)
Goetz-Grandmont, G.; Taheri, M.; Brunette, J.P.; Leroy, M.J.F.
Thermodynamic data are presented for indium extraction from low acidity media (pH value between 1 and 4) and at low concentration by a chelating extractant alone or associated to a solvatant or a lipophylic ammonium salt. Modifications in the nature and/or concentration of inorganic anions can transform the extraction process and allow to change metal distribution between phases [fr
Directory of Open Access Journals (Sweden)
Full Text Available Soxhlet, Ultrasonic extract of Morinda citrifolia L. fruit and four extracts from high pressure extraction at 10 MPa using ethanol, ethyl acetate as solvent and dried by vacuum oven and spray dryer were analyzed for their antioxidant activity by peroxide value method and diphenylpicrylhydrazyl radical scavenging method. The five extracts along with the reference samples, butylated hydroxyl toluene and tannic acid were further analyzed to determine their total phenolic content by Folin-Ciocalteau method and total flavonoid content by Dowd method. The M. citrifolia extract by high pressure extraction with ethyl acetate as solvent and spray dried was found to exhibit highest antioxidant activity and total flavonoid content. High total phenolic content was determined in the high pressure extract using ethyl acetate as solvent and vacuum dried. It was interesting to note that ultrasonic extract exhibited significant antioxidant activity, total phenolic and flavonoid content. High pressure extracted M. citrifolia in ethanol was found to express lesser values comparatively. The significant difference in activity among the high pressure extracts was found to be due to the polarity of the solvents used for extraction as M. citrifolia fruit contains relatively larger quantity of non-polar antioxidant compounds. It was also found that the drying methods had significant impact on the antioxidant activity, total phenolic and flavonoid content of the extracts.
Natural colorants: Pigment stability and extraction yield enhancement via utilization of appropriate pretreatment and extraction methods.
Ngamwonglumlert, Luxsika; Devahastin, Sakamon; Chiewchan, Naphaporn
Natural colorants from plant-based materials have gained increasing popularity due to health consciousness of consumers. Among the many steps involved in the production of natural colorants, pigment extraction is one of the most important. Soxhlet extraction, maceration, and hydrodistillation are conventional methods that have been widely used in industry and laboratory for such a purpose. Recently, various non-conventional methods, such as supercritical fluid extraction, pressurized liquid extraction, microwave-assisted extraction, ultrasound-assisted extraction, pulsed-electric field extraction, and enzyme-assisted extraction have emerged as alternatives to conventional methods due to the advantages of the former in terms of smaller solvent consumption, shorter extraction time, and more environment-friendliness. Prior to the extraction step, pretreatment of plant materials to enhance the stability of natural pigments is another important step that must be carefully taken care of. In this paper, a comprehensive review of appropriate pretreatment and extraction methods for chlorophylls, carotenoids, betalains, and anthocyanins, which are major classes of plant pigments, is provided by using pigment stability and extraction yield as assessment criteria.
Supercritical CO2 extraction of raw propolis and its dry ethanolic extract
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L. C. Paviani
Full Text Available Three types of propolis extract were prepared and analyzed with respect to their global extraction yields and with respect to the concentration of the following markers: 3,5-diprenyl-4-hydroxycinnamic acid; 3-prenyl-4-hydroxycinnamic acid; 4-hydroxycinnamic acid and 4-methoxy-3,5,7-trihydroxyflavone. The extract EEP (ethanolic extract of propolis was obtained by the conventional method from raw propolis using ethanol as solvent. The extracts (SFE were obtained by supercritical solvent extraction from the raw propolis using supercritical carbon dioxide (sc-CO2, with and without the addition of ethanol as a co-solvent. The fractionated supercritical extracts (FSCE were obtained by fractionation (extract and raffinate of the dry EEP with sc-CO2. EEP yields of 39.5% were obtained and maximum global extraction yields were 7.3% for SFE with no co-solvent, 51% for SFE with 15% ethanol and 18% for the FSCE extract fraction. The concentrations of the markers in the different extracts differed as a function of the operational parameters, indicating that the addition of co-solvent and the selectivity of sc-CO2 could be manipulated so as to obtain extracts with the yields and concentrations of interest.
Ultraviolet light assisted extraction of flavonoids and allantoin from aqueous and alcoholic extracts of Symphytum officinale
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Marwan S.M. Al-Nimer
Conclusions: UV-radiation enhances the yields of active ingredient, of comfrey extracted with methanol whereas improves the flavonoids, reducing power and allantoin levels of comfrey extracted by the aqueous infusion method. UV-radiation reduces the levels of flavonoids, reducing power and allantoin when the comfrey extracted by alcohols [J Complement Med Res 2017; 6(3.000: 280-283
Data Extraction Based on Page Structure Analysis
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Ren Yichao
Full Text Available The information we need has some confusing problems such as dispersion and different organizational structure. In addition, because of the existence of unstructured data like natural language and images, extracting local content pages is extremely difficult. In the light of of the problems above, this article will apply a method combined with page structure analysis algorithm and page data extraction algorithm to accomplish the gathering of network data. In this way, the problem that traditional complex extraction model behave poorly when dealing with large-scale data is perfectly solved and the page data extraction efficiency is also boosted to a new level. In the meantime, the article will also make a comparison about pages and content of different types between the methods of DOM structure based on the page and HTML regularities of distribution. After all of those, we may find a more efficient extract method.
Virgin almond oil: Extraction methods and composition
Energy Technology Data Exchange (ETDEWEB)
Roncero, J.M.; Alvarez-Orti, M.; Pardo-Gimenez, A.; Gomez, R.; Rabadan, A.; Pardo, J.E.
In this paper the extraction methods of virgin almond oil and its chemical composition are reviewed. The most common methods for obtaining oil are solvent extraction, extraction with supercritical fluids (CO2) and pressure systems (hydraulic and screw presses). The best industrial performance, but also the worst oil quality is achieved by using solvents. Oils obtained by this method cannot be considered virgin oils as they are obtained by chemical treatments. Supercritical fluid extraction results in higher quality oils but at a very high price. Extraction by pressing becomes the best option to achieve high quality oils at an affordable price. With regards chemical composition, almond oil is characterized by its low content in saturated fatty acids and the predominance of monounsaturated, especially oleic acid. Furthermore, almond oil contains antioxidants and fat-soluble bioactive compounds that make it an oil with interesting nutritional and cosmetic properties.
Research for actinides extractants from various wastes
International Nuclear Information System (INIS)
Musikas, C.; Cuillerdier, C.; Condamines, N.
This paper is an overview of the actinides solvent extraction research undertaken in Fontenay-aux-Roses. Two kinds of extractants are investigated; those usable for the improvement of the nowadays nuclear fuels reprocessing and those necessary for advanced fuels cycles which include the minor actinides (Np, Am) recovery for a further elimination through nuclear reactions. In the first class the mono and diamides, alternative to the organophosphorus extractants, TBP and polyfunctional phosphonates, showed promising properties. The main results are discussed. For the future efficient extractants for trivalent actinides-lanthanides group separations are suitable. The point about the actinides (III) - lanthanides (III) group separation chemistry and the development of some of these extractants are given
Audio feature extraction using probability distribution function
Suhaib, A.; Wan, Khairunizam; Aziz, Azri A.; Hazry, D.; Razlan, Zuradzman M.; Shahriman A., B.
Voice recognition has been one of the popular applications in robotic field. It is also known to be recently used for biometric and multimedia information retrieval system. This technology is attained from successive research on audio feature extraction analysis. Probability Distribution Function (PDF) is a statistical method which is usually used as one of the processes in complex feature extraction methods such as GMM and PCA. In this paper, a new method for audio feature extraction is proposed which is by using only PDF as a feature extraction method itself for speech analysis purpose. Certain pre-processing techniques are performed in prior to the proposed feature extraction method. Subsequently, the PDF result values for each frame of sampled voice signals obtained from certain numbers of individuals are plotted. From the experimental results obtained, it can be seen visually from the plotted data that each individuals' voice has comparable PDF values and shapes.
Antimicrobial screening of Cichorium intybus seed extracts
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Tauseef shaikh
Full Text Available Medicinal plants play an important role in the field of natural products and human health care system. Chemical constituents present in the various parts of the plants can resist to parasitic attack by using several defense mechanisms. One such mechanism is the synthesis of antimicrobial compound. Cichorium intybus is one of the important medicinal plants which belong to Asteraceae family. In the present work, antimicrobial screening of C. intybus seed extract was studied by agar well diffusion assay by using aqueous and organic extracts. The pathogenic microorganisms tested include Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Escherichia coli. All the seed extracts showed antimicrobial activity against tested microorganisms whereas S. aureus was found to be most sensitive against aqueous extract and had the widest zone of inhibition. Ethyl acetate and ethanol extract were found to be significant against P. aeruginosa and S. aureus. The results obtained from antimicrobial screening scientifically support the effectiveness of the medicinal plant.
Virgin almond oil: Extraction methods and composition
International Nuclear Information System (INIS)
Roncero, J.M.; Alvarez-Orti, M.; Pardo-Gimenez, A.; Gomez, R.; Rabadan, A.; Pardo, J.E.
In this paper the extraction methods of virgin almond oil and its chemical composition are reviewed. The most common methods for obtaining oil are solvent extraction, extraction with supercritical fluids (CO2) and pressure systems (hydraulic and screw presses). The best industrial performance, but also the worst oil quality is achieved by using solvents. Oils obtained by this method cannot be considered virgin oils as they are obtained by chemical treatments. Supercritical fluid extraction results in higher quality oils but at a very high price. Extraction by pressing becomes the best option to achieve high quality oils at an affordable price. With regards chemical composition, almond oil is characterized by its low content in saturated fatty acids and the predominance of monounsaturated, especially oleic acid. Furthermore, almond oil contains antioxidants and fat-soluble bioactive compounds that make it an oil with interesting nutritional and cosmetic properties.
Antimicrobial Effect of Extracts of Cruciferous Vegetables
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Shu-Hui Hu
Full Text Available The cruciferous vegetables cauliflower, broccoli, cabbage, Chinese radish, Chinese kale, and Chinese kitam were used in this study to prepare water-soluble and methanol-water extracts. Crude protein extracts were also obtained by diethylaminoethyl (DEAE anion exchange chromatography. Water-soluble polysaccharides were prepared by ethanol precipitation followed by ultrafiltration. The antimicrobial effects of all these extracts were evaluated against Gram-positive bacteria, Gram-negative bacteria, and yeast. Crude protein extracts exhibited the greatest antimicrobial activity in monoculture experiments. The antimicrobial effects of cruciferous vegetables were also studied by steeping beef, carrot, and celery in chlorine (10 ppm or citric acid solution (1% containing the crude protein extract (500 ppm for different time periods. Total aerobic plate counts and coliform counts on these foods decreased significantly after 10 minutes in all steeping solutions (p < 0.05.
Biomechanical considerations in mandibular incisor extraction cases.
Rachala, Madhukar Reddy; Aileni, Kaladhar Reddy; Dasari, Arun Kumar; Sinojiya, Jay
Mandibular incisor extraction can be regarded as a valuable treatment option in certain malocclusions to obtain excellence in orthodontic results in terms of function, aesthetics and stability. This treatment alternative is indicated in clinical situations like mild to moderate class III malocclusion, mild anterior mandibular tooth size excess, periodontally compromised teeth, ectopic eruption of mandibular incisor and minimal openbite tendencies. Unlike in premolar extraction cases, space closure in mandibular incisor extraction cases is unique in which the extraction space will be in the middle of the arch. The end result of space closure in these cases should be well aligned, upright, anterior teeth with parallel roots and the goal can be achieved with the bodily tooth movement through proper application of biomechanics. The purpose of this article is to explain the biomechanics of space closure in mandibular incisor extraction cases.
Rapid extraction of PCDD/Fs from soil and fly ash samples. Pressurized fluid extraction (PFE) and microwave-assisted extraction (MAE)
Energy Technology Data Exchange (ETDEWEB)
Sanz, P.; Fabrellas, B. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain)
The main reference extraction method in the analysis of polychlorinated dibenzop- dioxins and dibenzofurans (PCDD/Fs) is still the Soxhlet extraction. But it requires long extraction times (up to 24 hs), large volumes of hazardous organic solvents (100-300 ml) and its automation is limited. Pressurized Fluid Extraction (PFE) and Microwave-Assisted Extraction (MAE) are two relatively new extraction techniques that reduce the time and the volume of solvent required for extraction. However, very different PFE extraction conditions are found for the same enviromental matrices in the literature. MAE is not a extraction technique very applied for the analysis of PCDD/Fs yet, although it is used for the determination of other organic compounds, such as PCBs and PAHs. In this study, PFE and MAE extraction conditions were optimized to determine PCDDs y PCDFs in fly ash and soil/sediment samples. Conventional Soxhlet extraction with toluene was used to compare the extraction efficiency of both techniques.
Extraction of bioactive carbohydrates from artichoke (Cynara scolymus L.) external bracts using microwave assisted extraction and pressurized liquid extraction.
Ruiz-Aceituno, Laura; García-Sarrió, M Jesús; Alonso-Rodriguez, Belén; Ramos, Lourdes; Sanz, M Luz
Microwave assisted extraction (MAE) and pressurized liquid extraction (PLE) methods using water as solvent have been optimized by means of a Box-Behnken and 3(2) composite experimental designs, respectively, for the effective extraction of bioactive carbohydrates (inositols and inulin) from artichoke (Cynara scolymus L.) external bracts. MAE at 60 °C for 3 min of 0.3 g of sample allowed the extraction of slightly higher concentrations of inositol than PLE at 75 °C for 26.7 min (11.6 mg/g dry sample vs. 7.6 mg/g dry sample). On the contrary, under these conditions, higher concentrations of inulin were extracted with the latter technique (185.4 mg/g vs. 96.4 mg/g dry sample), considering two successive extraction cycles for both techniques. Both methodologies can be considered appropriate for the simultaneous extraction of these bioactive carbohydrates from this particular industrial by-product. To the best of our knowledge this is the first time that these techniques are applied for this purpose. Copyright © 2015 Elsevier Ltd. All rights reserved.
Comparison of different strategies for soybean antioxidant extraction.
Chung, Hyun; Ji, Xiangming; Canning, Corene; Sun, Shi; Zhou, Kequan
Three extraction strategies including Soxhlet extraction, conventional solid-liquid extraction, and ultrasonic-assisted extraction (UAE) were compared for their efficiency to extract phenolic antioxidants from Virginia-grown soybean seeds. Five extraction solvents were evaluated in UAE and the conventional extraction. The soybean extracts were compared for their total phenolic contents (TPC), oxygen radical absorbance capacity (ORAC), and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(*)) scavenging activities. The results showed that UAE improved the extraction of soybean phenolic compounds by >54% compared to the conventional and Soxhlet extractions. Among the tested solvents, 50% acetone was the most efficient for extracting soybean phenolic compounds. There was no significant correlation between the TPC and antioxidant activities of the soybean extracts. The extracts prepared by 70% ethanol had the highest ORAC values. Overall, UAE with 50% acetone or 70% ethanol is recommended for extracting soybean antioxidants on the basis of the TPC and ORAC results.
Comparative synergistic (technetium-actinide) extraction chemistry by tributylphosphate and some amide extractants
International Nuclear Information System (INIS)
Condamines, N.; Musikas, C.
In nuclear fuel reprocessing, technetium (TcO 4 - ) leads to bad interferences in the extractions, being synergistically co-extracted with different actinide cations as Uranium (VI), Plutonium (IV) and Zirconium (IV). It destroys the hydrazine in the reductive partition of U and Pu, it decreases the decontamination of U and Pu from fission products. Thus, its extraction behaviour with new extractants as N,N-diakylamides is useful to be known. TcO 4 - extraction in nitric acid media is compared for TBP and different amides. The influence of nitric acidity is related to the amides formula
Extraction of Glycyrrhizic Acid from Glycyrrhiza uralensis Using Ultrasound and Its Process Extraction Model
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Jiangqing Liao
Full Text Available This work focused on the intensification of extraction process of glycyrrhizic acid (GA from Glycyrrhiza uralensis using ultrasound-assisted extraction (UAE method. Various process parameters such as ultrasonic power, ultrasonic frequency, extraction temperature, and extraction time which affect the extraction yield were optimized. The results showed that all process parameters had exhibited significant influences on the GA extraction. The highest GA yield of 217.7 mg/g was obtained at optimized parameters of 125 W, 55 kHz, 25 °C, and 10 min. Furthermore, the extraction kinetics model of this process was also investigated based on Fick's first law available in the literature. Kinetic parameters such as equilibrium concentration (Ce and integrated influence coefficient (λ for different ultrasonic powers, ultrasonic frequencies, and extraction temperatures were predicted. Model validations were done successfully with the average of relative deviation between 0.96% and 4.36% by plotting experimental and predicted values of concentration of GA in extract. This indicated that the developed extraction model could reflect the effectiveness of the extraction of GA from Glycyrrhiza uralensis and therefore serve as the guide for comprehending other UAE process.
Selective and Efficient Solvent Extraction of Copper(II Ions from Chloride Solutions by Oxime Extractants
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Zahra Kaboli Tanha
Full Text Available Oxime extractants 3-tert-butyl-2-hydroxy-5-methyl benzaldehyde oxime (HL1 and 3-tert-butyl-2-hydroxy-5-methoxy benzaldehyde oxime (HL2 were synthesized and characterized by conventional spectroscopic methods. Suitable lipophilic nature of the prepared extractants allowed examining the ability of these molecules for extraction-separation of copper from its mixture with normally associated metal ions by performing competitive extraction experiments of Cu(II, Co(II, Ni(II, Zn(II, Cd(II and Pb(II ions from chloride solutions. Both ligands transfer selectively the copper ions into dichloromethane by a cation exchange mechanism. Conventional log-log analysis and isotherm curves showed that Cu(II ions are extracted as the complexes with 1:2 metal to ligand ratio by both extractants. Verification of the effect of the organic diluent used in the extraction of copper ions by HL1 and HL2 demonstrated that the extraction efficiency varies as: dichloromethane ~ dichloroethane > toluene > xylene > ethylacetate. Time dependency investigation of the extraction processes revealed that the kinetics of the extraction of copper by HL2 is more rapid than that of HL1. The application of the ligands for extraction-separation of copper ions from leach solutions of cobalt and nickel-cadmium filter-cakes of a zinc production plants was evaluated.
Enzyme assisted extraction of biomolecules as an approach to novel extraction technology: A review.
Nadar, Shamraja S; Rao, Priyanka; Rathod, Virendra K
An interest in the development of extraction techniques of biomolecules from various natural sources has increased in recent years due to their potential applications particularly for food and nutraceutical purposes. The presence of polysaccharides such as hemicelluloses, starch, pectin inside the cell wall, reduces the extraction efficiency of conventional extraction techniques. Conventional techniques also suffer from low extraction yields, time inefficiency and inferior extract quality due to traces of organic solvents present in them. Hence, there is a need of the green and novel extraction methods to recover biomolecules. The present review provides a holistic insight to various aspects related to enzyme aided extraction. Applications of enzymes in the recovery of various biomolecules such as polyphenols, oils, polysaccharides, flavours and colorants have been highlighted. Additionally, the employment of hyphenated extraction technologies can overcome some of the major drawbacks of enzyme based extraction such as longer extraction time and immoderate use of solvents. This review also includes hyphenated intensification techniques by coupling conventional methods with ultrasound, microwave, high pressure and supercritical carbon dioxide. The last section gives an insight on application of enzyme immobilization as a strategy for large scale extraction. Immobilization of enzymes on magnetic nanoparticles can be employed to enhance the operational performance of the system by multiple use of expensive enzymes making them industrially and economically feasible. Copyright © 2018 Elsevier Ltd. All rights reserved.
Evaluation of urinary cortisol excretion by radioimmunoassay through two methods (extracted and non-extracted)
International Nuclear Information System (INIS)
Fonte Kohek, M.B. da; Mendonca, B.B. de; Nicolau, W.
The objective of this paper is to compare the feasibility, sensitivity and specificity of both methods (extracted versus non-extracted) in the hypercortisolism diagnosis. It used Gamma Coat 125 cortisol Kit provided by Clinical Assays, Incstar, USA, for both methods extracting it with methylene chloride in order to measure the extracted cortisol. It was performed 32 assays from which it was obtained from 0.1 to 0.47 u g/d l of sensitivity. The intra-run precision was varied from 8.29 +- 3.38% and 8.19 +-4.72% for high and low levels, respectively for non-extracted cortisol, and 9.72 +- 1.94% and 9.54 +- 44% for high and low levels, respectively, for extracted cortisol. The inter-run precision was 15.98% and 16.15% for high level of non-extracted cortisol, respectively. For the low level it obtained 17.25% and 18.59% for non-extracted and extracted cortisol respectively. It was evaluated 24-hour urine basal samples from 43 normal subjects, and 53 obese (body mass index > 30) and 53 Cushing's syndrome patients. The sensitivity of the methods were similar (100% and 98.1% for non-extracted and extracted methods, respectively) and the specificity was the same for both methods (100%). It was noticed a positive correlation between the two methods in all the groups studied (p s syndrome. (author)
Potential of mangrove Avicennia rumphiana extract as an antioxidant agent using multilevel extraction
Sulmartiwi, L.; Pujiastuti, D. Y.; Tjahjaningsih, W.; Jariyah
Avicennia rumphiana is one of abundant mangrove found in Indonesia. Multilevel extraction methods were simultaneously conducted to screen the antioxidant activity from mangrove. The leaves, fruits and barks were consequently extracted using n-hexane, ethyl acetate and ethanol. The presence of phenolic, flavonoids and tannins compounds were characterized by quantitative and qualitative phytochemical assay as well as the antioxidant activity was examined using DPPH-free radical scavenging assay. The phytochemical test revealed that all of the extracts showed positive result. The fruits extract exhibited the highest phenolic, flavonoid and tannin (23.86 mg/g, 13.77 mg/g and 74.63 mg/g), respectively. The extracts were further confirmed for antioxidant using IC50 value and revealed that ethyl acetate extract has antioxidant activity better than n-hexane and ethyl acetate extract. Furthermore, this study indicated that mangrove Avicennia rumphiana could be subsequently explored for other biological activities due to their potential secondary metabolites.
Development of pressurised hot water extraction (PHWE) for essential compounds from Moringa oleifera leaf extracts.
Matshediso, Phatsimo G; Cukrowska, Ewa; Chimuka, Luke
Pressurised hot water extraction (PHWE) is a "green" technology which can be used for the extraction of essential components in Moringa oleifera leaf extracts. The behaviour of three flavonols (myricetin, quercetin and kaempferol) and total phenolic content (TPC) in Moringa leaf powder were investigated at various temperatures using PHWE. The TPC of extracts from PHWE were investigated using two indicators. These are reducing activity and the radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). Flavonols content in the PHWE extracts were analysed on high performance liquid chromatography with ultra violet (HPLC-UV) detection. The concentration of kaempferol and myricetin started decreasing at 150 °C while that of quercetin remained steady with extraction temperature. Optimum extraction temperature for flavonols and DPPH radical scavenging activity was found to be 100 °C. The TPC increased with temperature until 150 °C and then decreased while the reducing activity increased. Copyright © 2014 Elsevier Ltd. All rights reserved.
One-step extraction of polar drugs from plasma by Parallel Artificial Liquid Membrane Extraction
DEFF Research Database (Denmark)
Pilařová, Veronika; Sultani, Mumtaz; Ask, Kristine Skoglund
in the pores of a thin polymeric membrane, a well-known extraction principle also used in hollow fiber liquid-phase microextraction (HF-LPME). However, the new PALME technique offers a more user-friendly setup in which the supported liquid membrane is incorporated in a 96 well plate system. Thus, high......The new microextraction technique named parallel artificial liquid membrane extraction (PALME) was introduced as an alternative approach to liquid-liquid extraction of charged analytes from aqueous samples. The concept is based on extraction of analytes across a supported liquid membrane sustained...... for extraction of polar basic drugs was developed in the present work. The basic drugs hydralazine, ephedrine, metaraminol, salbutamol, and cimetidine were used as model analytes, and were extracted from alkalized human plasma into an aqueous solution via the supported liquid membrane. The extraction...
Massive clot formation after tooth extraction
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Santosh Hunasgi
Full Text Available Oral surgical procedures mainly tooth extraction can be related with an extended hemorrhage owed to the nature of the process resulting in an "open wound." The attempt of this paper is to present a case of massive postoperative clot formation after tooth extraction and highlight on the oral complications of surgical procedures. A 32-year-old male patient reported to the Dental Clinic for evaluation and extraction of grossly decayed 46. Clinical evaluation of 46 revealed root stumps. Extraction of the root stumps was performed, and it was uneventful. Hemostasis was achieved and postsurgical instructions were specified to the patient. The patient reported to the clinic, the very subsequent morning with a criticism of bleeding at the extraction site. On clinical examination, bleeding was noted from the socket in relation to 46. To control bleeding, oral hemostatic drugs Revici - E (Ethamsylate 500 mg was prescribed and bleeding was stopped in 2 h. However, a massive clot was formed at the extraction site. Further, this clot resolved on its own in 1-week time. Despite the fact that dental extraction is considered to be a minor surgical procedure, some cases may present with life-threatening complications including hemorrhage. Vigilant and significant history taking, physical and dental examinations prior to dental procedures are a must to avoid intraoperative and postoperative complications.
Binary solvent extraction system and extraction time effects on phenolic antioxidants from kenaf seeds (Hibiscus cannabinus L.) extracted by a pulsed ultrasonic-assisted extraction.
Wong, Yu Hua; Lau, Hwee Wen; Tan, Chin Ping; Long, Kamariah; Nyam, Kar Lin
The aim of this study was to determine the best parameter for extracting phenolic-enriched kenaf (Hibiscus cannabinus L.) seeds by a pulsed ultrasonic-assisted extraction. The antioxidant activities of ultrasonic-assisted kenaf seed extracts (KSE) were determined by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, β -carotene bleaching inhibition assay, and ferric reducing antioxidant power (FRAP) assay. Total phenolic content (TPC) and total flavonoid content (TFC) evaluations were carried out to determine the phenolic and flavonoid contents in KSE. The KSE from the best extraction parameter was then subjected to high performance liquid chromatography (HPLC) to quantify the phenolic compounds. The optimised extraction condition employed 80% ethanol for 15 min, with the highest values determined for the DPPH, ABTS, and FRAP assay. KSE contained mainly tannic acid (2302.20 mg/100 g extract) and sinapic acid (1198.22 mg/100 g extract), which can be used as alternative antioxidants in the food industry.
Some plant extracts retarde nitrification in soil
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Abdul–Mehdi S. AL-ANSARI
Full Text Available An incubation experiment was conducted to evaluate the effect of aqueous extracts of 17 plant materials on nitrification inhibition of urea- N in soil as compared with chemical inhibitor Dicyandiamide (DCD. Plant materials used in study were collected from different areas of Basrah province, south of Iraq. Aqueous extracts were prepared at ratio of 1:10 (plant material: water and added at conc. of 0.05, 0.10 and 0.20 ml g– 1 soil to loamy sand soil. DCD was added to soil at rate of 50 µg g-1 soil . Soil received urea at rate of 1000 µg N g-1 soil. Treated soils were incubated at 30 OC for 40 days. Results showed that application of all plant extracts, except those of casuarina, date palm and eucalyptus to soil retarded nitrification in soil. Caper, Sowthistle ,bladygrass and pomegranate extracts showed highest inhibition percentage (51, 42, 40 and 40 %, respectively and were found to be more effective than DCD (33 %. Highest inhibition was achieved by using those extracts at conc. of 0.1 ml g-1 soil after 10 days of incubation . Data also revealed that treated soil with these plant extracts significantly increased amount of NH4+–N and decreased amount of NO3-–N accumulation in soil compared with DCD and control treatments. Results of the study suggested a possibility of using aqueous extracts of some studied plants as potent nitrification inhibitor in soil.
Ultrasound assisted extraction of bioactive compounds
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Helena Drmić
Full Text Available Many novel and innovative techniques are nowadays researched and explored in order to replace or improve classical, thermal processing technologies. One of newer technique is technique of minimal food processing, under what we assume ultrasound processing. Ultrasound technology can be very useful for minimal food processing because transmission of acoustic energy through product is fast and complete, which allows reduction in total processing time, and therefore lower energy consumption. Industrial processing is growing more and more waste products, and in desire of preservation of global recourses and energy efficiency, several ways of active compounds extraction techniques are now explored. The goal is to implement novel extraction techniques in food and pharmaceutical industry as well in medicine. Ultrasound assisted extraction of bioactive compounds offers increase in yield, and reduction or total avoiding of solvent usage. Increase in temperature of treatment is controlled and restricted, thereby preserving extracted bioactive compounds. In this paper, several methods of ultrasound assisted extraction of bioactive compounds from plant materials are shown. Ultrasound can improve classic mechanisms of extraction, and thereby offer novel possibilities of commercial extraction of desired compounds. Application of sonochemistry (ultrasound chemistry is providing better yield in desired compounds and reduction in treatment time.
Binary Solvent Extraction System and Extraction Time Effects on Phenolic Antioxidants from Kenaf Seeds (Hibiscus cannabinus L.) Extracted by a Pulsed Ultrasonic-Assisted Extraction
Lau, Hwee Wen; Nyam, Kar Lin
The aim of this study was to determine the best parameter for extracting phenolic-enriched kenaf (Hibiscus cannabinus L.) seeds by a pulsed ultrasonic-assisted extraction. The antioxidant activities of ultrasonic-assisted kenaf seed extracts (KSE) were determined by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, β-carotene bleaching inhibition assay, and ferric reducing antioxidant power (FRAP) assay. Total phenolic content (TPC) and total flavonoid content (TFC) evaluations were carried out to determine the phenolic and flavonoid contents in KSE. The KSE from the best extraction parameter was then subjected to high performance liquid chromatography (HPLC) to quantify the phenolic compounds. The optimised extraction condition employed 80% ethanol for 15 min, with the highest values determined for the DPPH, ABTS, and FRAP assay. KSE contained mainly tannic acid (2302.20 mg/100 g extract) and sinapic acid (1198.22 mg/100 g extract), which can be used as alternative antioxidants in the food industry. PMID:24592184
Binary Solvent Extraction System and Extraction Time Effects on Phenolic Antioxidants from Kenaf Seeds (Hibiscus cannabinus L. Extracted by a Pulsed Ultrasonic-Assisted Extraction
Directory of Open Access Journals (Sweden)
Yu Hua Wong
Full Text Available The aim of this study was to determine the best parameter for extracting phenolic-enriched kenaf (Hibiscus cannabinus L. seeds by a pulsed ultrasonic-assisted extraction. The antioxidant activities of ultrasonic-assisted kenaf seed extracts (KSE were determined by a 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging capacity assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS radical scavenging assay, β-carotene bleaching inhibition assay, and ferric reducing antioxidant power (FRAP assay. Total phenolic content (TPC and total flavonoid content (TFC evaluations were carried out to determine the phenolic and flavonoid contents in KSE. The KSE from the best extraction parameter was then subjected to high performance liquid chromatography (HPLC to quantify the phenolic compounds. The optimised extraction condition employed 80% ethanol for 15 min, with the highest values determined for the DPPH, ABTS, and FRAP assay. KSE contained mainly tannic acid (2302.20 mg/100 g extract and sinapic acid (1198.22 mg/100 g extract, which can be used as alternative antioxidants in the food industry.
Directory of Open Access Journals (Sweden)
Full Text Available ABSTRACT In the present work were evaluated the effects of propolis coatings of various botanical sources on quality traits of bananas cv. Prata (Musa sapientum L. stored at room temperature. ´Prata´ bananas were selected and submitted to five postharvest treatments: four coatings applied by immersion in propolis extracts at a concentration of 2.5% (w/v and a control (without coating. Propolis extracts were applied as 1 a wild type aqueous propolis extract, 2 a wild type hydroalcoholic propolis extract, 3 a rosemary green type hydroalcoholic propolis extract and 4 a red type hydroalcoholic propolis extract. The bananas were evaluated at three-day intervals along 12 days for fresh weight losses, flesh firmness, soluble solids (SS, titratable acidity (TA, the ratio SS/TA and pH. Sensory analyses were performed after three and six days of storage by 55 not trained panelists designed for acceptability. At the end of the twelve-day storage period, bananas coated either with the rosemary green hydroalcoholic extract or with the aqueous extract presented lower fresh weight losses in comparison to the bananas of the control treatment. No differences were determined in relation to flesh firmness and along the storage period TA values decreased and pH values increased in bananas of all treatments. SS contents increased towards the end of the storage period that, consequently, contributed to increases in the SS/TA ratio. The most significant increase in SS/TA ratio was determined in bananas coated with the red type hydroalcoholic extract. Taste panelists did not detect significant differences amongst coated and not coated cv. Prata bananas up to six days of storage.
Neutron activation analysis of medicinal plant extracts
International Nuclear Information System (INIS)
Vaz, S.M.; Saiki, M.; Vasconcellos, M.B.A.; Sertie, J.A.A.
Instrumental neutron activation analysis was applied to the determination of the elements Br, Ca, Cl, Cs, Fe, K, La, Mg, Mn, Na, Rb and Zn in medicinal extracts obtained from Centella asiatica, Citrus aurantium L., Achyrolcline satureoides DC, Casearia sylvestris, Solano lycocarpum, Zingiber officinale Roscoe, Solidago microglossa and Stryphnondedron barbatiman plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyldithiocarbamate solution. Precision and accuracy of the results were evaluated by analyzing biological reference materials. The therapeutic action of some elements found in plant extracts analyzed is briefly discussed. (author). 15 refs., 5 tabs
First beam extracted from the SSC
International Nuclear Information System (INIS)
On the 25th July 1986 the first 2,8 μA 66 MeV proton beam was successfully extracted from the separated sector cyclotron (SSC) at the National Accelerator Centre at Faure, South Africa. The beam has now also been transported for the first time down the high-energy beamline up to the last Faraday cup in front of the neutron therapy vault. A brief description of the extraction system of the SSC, consisting of an electrostatic extraction channel and two septum magnets is given
Directory of Open Access Journals (Sweden)
Liudmila V. Dyakova
Full Text Available The paper deals with the extracting cobalt salts by using mixtures on the basis of tertiary amine from multicomponent solutions from the process of hydrochloride leaching of cobalt concentrate. The optimal composition for the extraction mixture, the relationship between the cobalt distribution coefficients and modifier's nature and concentration, and the saltingout agent type have been determined. A hydrochloride extraction technology of cobalt concentrate yielding a purified concentrated cobalt solution for the production of pure cobalt salts has been developed and introduced at Severonikel combine.
Software for Extracting 3D - MSSTs
DEFF Research Database (Denmark)
Somchaipeng, Kerawit; Sporring, Jon; Kreiborg, Sven
The deep structure of an image is investigated, and a Multi-Scale Singularity Tree (MSST) is constructed based on the pair-wise annihilations of critical points. This report contains two main contributions. Firstly, we describe a fast, simple, and robust method of extracting feature lines from data...... sets of up to four dimen- sions, which we apply in order to extract critical paths from scale-spaces. Secondly, we investigate the extracting of MSSTs using either support regions or extrema partitions. Given an image, both methods produce a binary tree that mathematically represents the topological...
Nootropic effect of meadowsweet (Filipendula vulgaris) extracts.
Shilova, I V; Suslov, N I
The effects of the extracts of the aboveground parts of Filipendula vulgaris Moench on the behavior and memory of mice after hypoxic injury and their physical performance in the open-field test were studied using the models of hypoxia in a sealed volume, conditioned passive avoidance response (CPAR), and forced swimming with a load. The extracts improved animal resistance to hypoxia, normalized orientation and exploration activities, promoted CPAR retention after hypoxic injury, and increased physical performance. Aqueous extract of meadowsweet had the most pronounced effect that corresponded to the effect of the reference drug piracetam. These effects were probably caused by modulation of hippocampal activity.
Newer methods of extraction of teeth
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MHendra Chandha
Full Text Available Atraumatic extraction methods are deemed to be important to minimize alveolar bone loss after tooth extraction. With the advent of such techniques, exodontia is no more a dreaded procedure in anxious patients. Newer system and techniques for extraction of teeth have evolved in the recent few decades. This article reviews and discusses new techniques to make simple and complex exodontias more efficient with improved patient outcomes. This includes physics forceps, powered periotome, piezosurgery, benex extractor, sonic instrument for bone surgery, lasers.
Antimicrobial activity of Gentiana lutea L. extracts.
Savikin, Katarina; Menković, Nebojsa; Zdunić, Gordana; Stević, Tatjana; Radanović, Dragoja; Janković, Teodora
Methanolic extracts of flowers and leaves of Gentiana lutea L., together with the isolated compounds mangiferin, isogentisin and gentiopicrin, were used to investigate the antimicrobial activity of the plant. A variety of Gram-positive and Gram-negative bacteria as well as the yeast Candida albicans has been included in this study. Both extracts and isolated compounds showed antimicrobial activity with MIC values ranging from 0.12-0.31 mg/ml. Our study indicated that the synergistic activity of the pure compounds may be responsible for the good antimicrobial effect of the extracts. Quantification of the secondary metabolites was performed using HPLC.
Solvent extraction in the nuclear fuel cycle
International Nuclear Information System (INIS)
Eccles, H.; Naylor, A.
Solvent extraction techniques have been used in the uranium nuclear fuel cycle in three main areas; concentration of uranium from ore leach liquor, purification of ore concentrates and fuel reprocessing. Solvent extraction has been extended to the removal of transuranic elements from active waste liquor, the recovery of uranium from natural sources and the recovery of noble metals from active waste liquor. Schemes are presented for solvent extraction of uranium using the Amex or Dapex process; spent fuel reprocessing and the Purex process. Recent and future developments of the techniques are outlined. (UK)
Extraction products of solid carbonaceous materials
Energy Technology Data Exchange (ETDEWEB)
A method is described for the manufacture of liquid products from pressure extracts of solid carbon-containing material by destructive hydrogenation, characterized in that the pressure extracts are hydrogenated in admixture with products of high-molecular weight formed during a previous destructive hydrogenation of another part of the same or other pressure extract and which has been collected as liquid without extensive cooling of the hot products of the reaction, which came from the reaction chamber where the previous destructive hydrogenation took place.
Extraction of latent images from printed media
Sergeyev, Vladislav; Fedoseev, Victor
In this paper we propose an automatic technology for extraction of latent images from printed media such as documents, banknotes, financial securities, etc. This technology includes image processing by adaptively constructed Gabor filter bank for obtaining feature images, as well as subsequent stages of feature selection, grouping and multicomponent segmentation. The main advantage of the proposed technique is versatility: it allows to extract latent images made by different texture variations. Experimental results showing performance of the method over another known system for latent image extraction are given.
Spreadsheet algorithm for stagewise solvent extraction
International Nuclear Information System (INIS)
Leonard, R.A.; Regalbuto, M.C.
The material balance and equilibrium equations for solvent extraction processes have been combined with computer spreadsheets in a new way so that models for very complex multicomponent multistage operations can be setup and used easily. A part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets. 22 refs., 4 figs., 2 tabs
Sequential extraction of uranium metal contamination
International Nuclear Information System (INIS)
Murry, M.M.; Spitz, H.B.; Connick, W.B.
Samples of uranium contaminated dirt collected from the dirt floor of an abandoned metal rolling mill were analyzed for uranium using a sequential extraction protocol involving a series of five increasingly aggressive solvents. The quantity of uranium extracted from the contaminated dirt by each reagent can aid in predicting the fate and transport of the uranium contamination in the environment. Uranium was separated from each fraction using anion exchange, electrodeposition and analyzed by alpha spectroscopy analysis. Results demonstrate that approximately 77 % of the uranium was extracted using NH 4 Ac in 25 % acetic acid. (author)
Actinide extractants for the nuclear industry of the future
International Nuclear Information System (INIS)
Musikas, C.; Morisseau, J.C.; Hoel, P.; Guillaume, B.
Non organo-phosphorus extractants properties regarding the extractions of actinides in nuclear fuels reprocessing are presented. N,N-dialkylamides are proposed as alternatives to TBP.N,N'-tetraalkylamides or pentaalkyl propane diamides properties are reported. They show that those bidentate extractants are alternatives to bidentate organophosphorus extractants for actinides (III) extraction from concentrated nitric acid. 11 figs, 15 refs
Pain and chewing sensitivity during fixed orthodontic treatment in extraction and non-extraction patients.
Sayar, Gulsilay
The aim of this study was to evaluate the differences in pain perception and chewing sensitivity between extraction and non-extraction patients. Thirty orthodontic patients (11 males, 19 females) were included in this study who were classified as extraction (n=15; 6 males, 9 females) and non-extraction patients (n=15; 7 males, 8 females). The mean age of patients were 15.10±1.83 years in non-extraction group and 15.44±0.75 years in extraction group. The patients were asked to complete the Visual Analogue Scale (VAS) questionnaire and they were asked to mark the presence or absence of sensitivity during 7 days after the first arch wire placement. Pain intensity comparison between groups was performed using the Mann-Whitney U test. The Friedman test was used to analyze within-group differences over time. There were no significant differences in pain scores between the groups. Pain levels significantly decreased between day 1 and day 3 in both the groups. No differences were found in the chewing sensitivity between the non-extraction and extraction groups. No difference in the pain perception was observed between the extraction and non-extraction patients during the 7 days after arch wire placement.
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Gülşilay SAYAR
Full Text Available Purpose: The aim of this study was to evaluate the differences in pain perception and chewing sensitivity between extraction and non-extraction patients. Subjects and Methods: Thirty orthodontic patients (11 males, 19 females were included in this study who were classified as extraction (n=15; 6 males, 9 females and non-extraction patients (n=15; 7 males, 8 females. The mean age of patients were 15.10±1.83 years in non-extraction group and 15.44±0.75 years in extraction group. The patients were asked to complete the Visual Analogue Scale (VAS questionnaire and they were asked to mark the presence or absence of sensitivity during 7 days after the first arch wire placement. Pain intensity comparison between groups was performed using the Mann-Whitney U test. The Friedman test was used to analyze within-group differences over time. Results: There were no significant differences in pain scores between the groups. Pain levels significantly decreased between day 1 and day 3 in both the groups. No differences were found in the chewing sensitivity between the non-extraction and extraction groups. Conclusion: No difference in the pain perception was observed between the extraction and non-extraction patients during the 7 days after arch wire placement.
Antioxidant activities of extracts from five edible mushrooms using different extractants
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Suphaphit Boonsong
Full Text Available Extractions were performed of the total phenolic and flavonoid contents and antioxidant properties of five edible mushroom samples—Lentinus edodes, Volvariella volvacea, Pleurotus eous, Pleurotus sajor-caju and Auricularia auricular—using three different extractants. Among the three different extractants, 50% (volume per volume; v/v ethanol was the most suitable for antioxidant extraction from the mushroom samples. The 50% (v/v ethanolic extract of dried L. edodes contained higher total phenolic and flavonoid contents than in the other mushroom extract samples. The antioxidant activities of 50% (v/v ethanolic extract of dried L. edodes showed the strongest 2,2-diphenyl-1-picrylhydrazyl radical-scavenging assay (64.34% compared to butylated hydroxyanisole (BHA and α-tocopherol at 500 μg/mL. The ethanolic extract showed a lower reducing power of 0.10 compared to BHA and α-tocopherol at 500 μg/mL. Moreover, the L. edodes ethanolic extract also had the highest chelating ability (66.28% which was lower than for ethylenediaminetetraacetic acid at 500 μg/mL and showed the strongest superoxide radical-scavenging activity (64.17% compared to BHA and α-tocopherol. Therefore, the 50% (v/v ethanolic extract of L. edodes could be used as a potential natural antioxidative source or as an ingredient in the fish and fishery product industries.
Separation of digoxin by luiquid-luiquid extraction from extracts of foxglove secondary glycosides
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Novković Vesna V.
Full Text Available The present study deals with the extraction of digoxin (Dgx from chloroform and trichloroethylene extracts of the secondary glycosides of fermented foxglove (Digitalis lanata Ehrh. foliage by liquid-liquid extraction. The extraction degree (ED of Dgx achieved by maceration and percolation using 10% vol. aqueous ethanol solutions were higher than 95%. Using trichlorethylene and chloroform, the ED of Dgx of about 100% and 96%, respectively from the liquid ethanolic extracts (macerate or percolate were achieved by the four-cycle extraction. Fifteen separating funnels were employed for the liquid-liquid extraction. Three different four-component two-phase systems (ethanol:water - chloroform:ethyl acetate, ethanol:water - chloroform:trichloroethylene and ethanol:water - trichloroethylene:ethyl acetate were tested as an extracting solvent to get the final product having more than 98% of Dgx. The initial amount of the chloroform or trichloroethylene extract in the light phase was varied between 5 and 25 g/L, while the volume ratio of light and heavy phases was in the range of 1:1 to 1:2. The best Dgx yield of 98% was achieved with the system ethanol:water - chloroform:trichloroethylene 35:15:20:30 at the volume ratio of the phases of 1:1.1 and at the initial amount of the extract of 15 g/L. Purity of the separated digoxin was 99.8 %. [Projekat Ministarstva nauke Republike Srbije, br. TR-34012