the acceptor phase, the membrane interface configured for  bathing in the sample, under ambient pressure, the acceptor  phase delivery capillary in fluid communication with the  acceptor phase supply, the ionization source and the mass  spectrometer.  9.  The system of claim  1,  further comprising a mixer for  mixing the sample.  10.  An immersion probe for use with an ionization source  and a mass spectrometer, the immersion probe comprising a  membrane interface coaxial with an acceptor phase delivery  capillary and for fluid communication with an acceptor  phase, the membrane interface configured for bathing in the  sample, under ambient pressure, the acceptor phase delivery  capillary for fluid communication with acceptor phase sup› ply, the ionization source and the mass spectrometer.  US 9,583,325 B2  34  33  TABLE 3  TABLE 4  $^{1}$plasma deposited thin film PDMS on microporous polypropylene, neoMecs Inc. (O.D. = 0.264; I.D. = 0.263)  $^{2}$MedArray Inc (O.D.  =  0.24 mm; l.D.  =  0.17 mm)  $^{3}$Silastic Dow-Corning (O.D. = 0.64 mm; I.D. = 0.30 mm)  What is claimed is:  1.  A system for analyzing a sample comprising an analyte,  the system comprising:  an acceptor phase supply comprising an acceptor phase;  an ionization source;  a mass spectrometer; and  a membrane interface device, the device compnsmg a  membrane interface in fluid communication with an  acceptor phase carrier, the membrane interface config› ured for bathing in the sample, under ambient pressure,  the acceptor phase carrier in fluid communication with  the acceptor phase supply, the ionization source and the  mass spectrometer.  2.  The system of claim  1,  wherein the membrane interface  is a hollow fibre membrane (HFM) comprising polydimeth› ylsiloxane, ofno more than about 225 microns in thickness.  3.  The system of claim  2,  wherein the membrane is a thin 55  membrane.  4.  The system of claim  2,  wherein the membrane is a  supported liquid membrane.  5.  The system of claim  2,  wherein the probe is a  J  probe.  6.  The system of claim  2,  wherein the probe is a miniature 60  coaxial probe.  7.  The system of claim  6,  further comprising an autosam› pler.  8.  The membrane interface device of claim  6,  wherein the  miniature coaxial probe is an immersion probe, the probe  comprising a membrane interface coaxial with-an acceptor  phase delivery capillary and for fluid communication with  17.  The method of claim  15,  wherein the measuring and  quantifying provides direct, in vivo or in situ monitoring of  the biological or the environmental sample.  16.  The method of claim  15,  further comprising rapid  prescreening the sample and providing the sample for fur› ther analyzing.  15.  The method of claim  14,  wherein the sample is a  biological sample or an environmental sample.  14.  The method of claim  13,  wherein the measuring is  direct.  delivering the analyte to an ionization source and to a  mass spectrometer; and obtaining an output, thereby  quantifying and measuring the trace level analyte.  delivering an acceptor phase to the membrane interface  device via an acceptor phase carrier;  moving the sample over the membrane interface device;  exposing a membrane interface device to a sample, such  that the membrane interface device is bathed in the  sample;  13.  A method of quantifying and measuring a trace level  analyte in a sample, the sample being between about 1.0 µL  to about 1 mL, the method comprising:  12.  The probe of claim  11,  wherein the HFM is a  composite PDMS micro-porous polypropylene HFM, a thin  PDMS HFM or a supported liquid membrane HFM.  11.  The probe of claim  10,  wherein the membrane inter› face is a hollow fibre membrane (HFM) comprising poly- dimethylsiloxane, of about 0.5 microns to about 225 microns  in thickness.  Analysis of signal-to-noise ratios (SIN) and average signal  rise times for selected NA obtained for Merichem NA in  DI and River Water spiked at 440 ppb total NA.  Molecular  Formula  m/z  DI Water  C9H1s02  157  25.5  C13H2202  209  123  C13H2402  211  81.1  C13H2602  213  64.3  C1sH2602  237  180  C16H2s02  251  420  SIN Ratios  River Water  22.1  17.6  12.5  17.5  22.5  32.8  Average  t$_{10}$ _ $_{90}$%/min.  0.7  1.0  1.0  1.3  1.2  1.2  C17H3002  265  70.4  C1SH3202  279  75.8  44.0  22.3  1.5  1.4  Performance characteristics for selected naphthenic acid isomer families  (CnH$_{2}$n+z0$_{2}$ )  for Merichem mixture using ’J-probe’ immersion  type interface with  2  cm membrane length.  Membrane  PDMS  thickness  0.5  µrn  composite 1  35  µrn 2  170  µrn 3  m/z  Isomer  class  n, z  213  13, 0  14, -6  0.6  10  10  Response Times  t  mins  223  237  251  14, -2  15, -2  16, -2  15, -8  16, -8  17, -8  0.6  0.6  0.7  15  15  20  15  25  25  Sensitivity  Est. DLs (ppb)  305  213  223  237  251  305  20, -3  13, 0  14, -2  15, -2  16, -2  20, -3  21, -9  14, -6  15, -8  16, -8  17, -8  21, -9  3.0  20  20  40  30  30  20  10  5  20  20  20  30  10  5  5  5  10 