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Development and application of methods for the determination of pesticide residues in natural waters and sediments, coupled to GC-MS

The main objectives of this study were to develop rapid and accurate screening multiresidue pesticide methods on the basis of Solid-Phase Extraction (SPE) technique for the determination of 10 pesticides in water samples and on the basis of QuEChERS technique regarding sediments samples. The target compounds were determined by Gas Chromatography-Mass Spectrometry (GC-MS). The method was validated in terms of accuracy, precision, linearity, detection and quantification limits. The recovery percentages obtained for the pesticides in water samples at three different concentration levels, ranged between 73.2 to 101.2%, with relative standard deviations below 9.3%. The corresponding results from the sediment ranged between 69.5 to 122.7% with relative standard deviations below 11.2%. The limits of detection for the pesticides in water and sediment were below 12 ng L-1 and 9 mg kg-1, respectively. The optimized methods were applied in Epirus region (North-Western Greece) to determine the concentration level of the target compounds in sea water and sediment samples. The analytical methodologies exhibited excellent analytical characteristics and proved to be reliable for the estimation of the pollutant load in sea water and sediment samples from marine aquaculture.