最新刊期
卷 34 ， 期 9 ， 2015
- 摘要：A generic，rapid and simple multiresidue analytical method was developed and validated for determination of 8 classes of drugs including 17 β-agonists，18 β-lactams，6 coccidiostats，5 macrolides，2 lincosamides，15 quinolones，21 sulfonamides and 3 sulfonamides potentiators in feedingstuffs using dispersive solid-phase extraction(dSPE) method and high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The homogenized sample was dispersed by 0.1 mol/L Na2EDTA solution，the analytes were extracted with a mixture of methanol-acetonitrile(50∶50) by ultrasonic，and then the extracts were purified by dispersive solid phase extraction using Bondesil-PSA as adsorbent.Electrospray ionization mass spectrometry was operated in the positive mode using dynamic multiple reaction monitor(dMRM) for the qualitative and quantitative analysis of 87 kinds of analytes after the separation on a Poroshell EC-C18(100 mm×2.1 mm，2.4 μm) column.The correlation coefficients of linear calibration curves were over 0.99 in the corresponding concentration range.The average recoveries of 87 drugs at three different spiked concentration levels ranged from 63.7% to 108.8%，with relative standard deviations(RSDs) of 3.5%-15.2%.The limits of detection(LODs，S/N≥3) and quantitation(LOQs，S/N≥10) were 3-15 μg/kg and 10-50 μg/kg，respectively.The method was simple，rapid，sensitive and reliable，and was suitable for the determination of residues in feedingstuffs.关键词：dispersive solid-phase extraction(dSPE);high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS);dynamic multiple reaction ion monitoring(dMRM);feedingstuffs;β-agonists;coccidiostats;antibiotics
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发布时间： - 摘要：An analytical method was established for the simultaneous determination of 24 pesticides in putrefied blood by ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF-MS)．The QuEChERS(Quick，Easy，Cheap，Effective，Rugged，and Safe) method was used for sample preparation．The analytes were extracted with acetonitrile-waters(4∶1) by supersonic， dehydrated by adding anhydrous magnesium sulfate，and penetrated with 0.22 μm membrane．The separation of 24 target compounds were performed on an ACQUITY UPLCTM HSS C18 column with gradient elution using acetonitrile-0.1% formic acid/ammonium formate as mobile phase.MS acquisition under positive ion mode was used to obtain accurate relative molecular masses and fragment ions．As a result，the limits of detection(LOD，S/N=3) of the target compounds were in the range of 0.43-10.0 ng/mL．The average recoveries of 24 analytes at three spiked concentration levels ranged from 61% to 98% with relative standard deviations of 1.5%-16.9%.This method could be applied in the analysis of 24 pesticides in putrefied blood due to its fastness，simplicity and relatively high sensitivity．关键词：ultra performance liquid chromatography coupled with quadrupole-time of flight-mass spectrometry( UPLC-Q-TOF-MS);pesticide;putrefied blood
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发布时间： - 摘要：A liquid chromatography-tandem mass spectrometric（LC-MS/MS） method was established for the determination of glufosinate-ammonium residue in vegetables and fruits.The samples spiked with d3-glufosinate，the internal standard，were extracted with water，defatted with dichloromethane，and cleaned up using a strong cation exchange column，then derived with 9-fluorenylmethylchloroformate（FMOC-Cl） overnight.The separation of the target compound was performed on a C18 column（4.6 mm×50 mm，1.8 μm） using 5 mmol/L ammonium acetate（containing 0.1% formic acid）-acetonitrile（containing 0.1% formic acid） as mobile phase.The identification and quantitation of glufosinate were performed by MS/MS in positive electrospray ionization（ESI+） and multiple reaction monitoring（MRM） mode.The quantitative analysis was carried out by the internal standard method.The calibration curve showed a good linearity in the range of 0-200 μg/L with a correlation coefficient greater than 0.995.The limit of detection（LOD） and the limit of quantitation（LOQ） of this method were 10 μg/kg and 20 μg/kg，respectively.The average recoveries of glufosinate in foods at three spiked levels of 20，200,500 μg/kg were in the range of 80.8%-102.2% with relative standard deviations（RSDs） of 1.8%-7.9%.The application of internal standard effectively reduced the influence of matrix effects.The results of validation tests indicated that the method was sensitive and accurate,and was suitable for the monitoring of glufosinate residue in vegetables and fruits.关键词：glufosinate;residue;solid phase extraction;liquid chromatography-tandem mass spectrometry
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发布时间： - 摘要：It is important to establish comprehensive indexes for evaluating oil quality and ensure the safety of edible oils.The physicochemical indicators(e.g.peroxide value,conjugated diene,conjugated triene,anisidine value,acid value,iodine value,total polar compound) of sunflower oil oxidized at 105 ℃ and 180 ℃ were investigated firstly,then the oil quality evaluation model were developed by the principal component analysis(PCA),and the contributive degree of physicochemical indicators to sunflower oil quality was compared.The comprehensive indexes for sunflower oil quality monitoring and evaluation at 105 ℃ and 180 ℃ were implemented by the PCA model.The results indicated that conjugated diene(K232),conjugated triene(K270),β-anisidine value(PAV),acid value(AV) and total polar compound(TPC) increased significantly(P≤0.05) during the oxidation process,while the iodine value(IV) decreased and the peroxide value(POV) fluctuated.After taking over the overall rate of change(ORC) of all physical and chemical indicators and correlations between the physicochemical indexes and UFA/SFA(UFA-unsaturated fatty acid,SFA-saturated fatty acid),peroxide value(105 ℃) or total polar compound(180 ℃),indicators(105 ℃/peroxide value,conjugated diene,anisidine value;180 ℃:conjugated diene,anisidine value,total polar compound) were chosen to judge the sunflower oil quality accurately.Comprehensive indexes were achieved by PCA based on information fusion,and the critical value is -0.189(105 ℃) and 0.727(180 ℃),respectively.On the other hand,conjugated diene and anisidine value could be used to distinguish well the sunflower oils oxidized under different temperatures(105 ℃ and 180 ℃) based on PCA.关键词：sunflower oil;physicochemical indicators;principal component analysis(PCA);comprehensive evaluation
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发布时间： - 摘要：A rapid method was developed for the simultaneous determination of 20 synthetic colors in cured meat products by high performance liquid chromatography(HPLC) with sub-3 μm columns.The samples were degreased with petroleum benzin，extracted with ethanol-ammonium hydroxide-water(7∶2∶1) and deproteinized with sodium tungstate solution.The target compounds were separated on an Agilent Poroshell 120 EC C18 column(50 mm×4.6 mm,2.7 μm) using methanol-0.02 mol/L ammonium acetate solution(pH 5.5) as mobile phase with gradient elution，and detected with DAD.The quantification analysis of analytes was performed by the external standard method.The result indicated -that 20 analytes were separated completely in 17 min，and their calibration curves were linear in the range of 0.15-20.0 mg/L with correlation coefficients more than 0.998. The average recoveries at three spiked levels ranged from 70.3% to 107.9% with RSDs(n=6) of 0.5%-3.1%.The detection limits were in the range of 0.1-0.2 mg/kg. The method approximately reduced assay time by 62% compared with that of the regular ACE C18 column(250 mm×4.6 mm，5 μm).The method could be performed routinely on a conventional LC system,which indicates an extensive application prospect.关键词：sub-3 μm particle column;adulterate;synthetic colors;high performance liquid chromatography(HPLC);cured meat product
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发布时间： - 摘要：To achieve sensitive detection of catecholamines in trace rat brain microdialysate samples,using d0/d3-10-methyl-acridone-2-sulfonyl chloride（d0/d3-MASC) as isotope-coded derivatization, a novel ultra high performance liquid chromatography-tandem mass spectrometry（UHPLC-MS/MS) method was developed for the detection of dopamine（DA),norepinephrine（NE) and epinephrine（EP) by ultrasonic-assisted dispersive liquid-liquid microextraction（UA-DLLME).d0-MASC（light form) and d3-MASC（heavy form) were used as derivatization reagents for microdialysate samples and standards,respectively.The mixture of two solutions was enriched by dispersive liquid-liquid microextraction,and 3 catecholamines were detected by UHPLC-MS/MS with heavy derivatives as internal standards for corresponding light derivatives.The result indicated that the stable derivatives were obtained in pH 10.8 buffer/acetonitrile at 37 ℃ for 3.0 min,and then were separated within 3.0 min.Linearity ranges were obtained in the range of 0.02-10.0 nmol/L（r>0.995) for three catecholamines, with LODs of 0.005-0.010 nmol/L and LOQs of 0.018-0.040 nmol/L.Compared with the reported methods,the method is a convenient and validated method for the sensitive and accurate determination of catecholamines in trace rat brain microdialysates.关键词：in vivo microdialysis;Parkinson’s disease;multiple reaction monitoring(MRM);stable isotope label
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发布时间： - 摘要：A novel method for the simultaneous determination of total specific migration limit of UV-24，UV-0，UV-9，DHBP，UV-531，HHBP，UV-P，UV-327 and UV-326 in food simulants（10% ethanol，20% ethanol，50% ethanol，3% acetic acid and olive oil） was developed using high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.After the migration test，the soaking solution was cooled down，and homogenized.Olive oil food simulant was extracted with acetonitrile and n heptane，the clear acetonitrile solution and other aqueous food stimulant diluted with ethanol（1∶10） were filtered through a hydrophilic polytetrafluoroethylene filter with a disposable syringe before injection.The SunFireTM C8 column and gradient elution were selected to separate.The AB Qtrap 4500 tandem quadrupole mass spectrometer was operated under multiple reaction monitoring（MRM） and ESI-mode.The limits of quantitation were between 0.01 mg/kg and 0.30 mg/kg.The linearity of the method was good with correlation coefficients（r） not less than 0.995 4 over the certain concentration range .The recoveries at spiked concentration levels of 1-35 mg/kg were between 80.0% and 127% with relative standard deviations of 0.8%-8.0%.With the high sensitivities，good recoveries and accuracies，the method could be applied for the analysis of food contact material samples.关键词：high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;ultraviolet absorbents;total specific migration limit;food simulants
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发布时间： - 摘要：Under the simulative human physiological conditions，using nano-TiO2 as the control，the interaction of GR-TiO2 with lysozyme（LYSO） was investigated by ultraviolet spectrometry，fluorescence spectroscopy，synchronous fluorescence spectroscopy，three dimensional fluorescence spectroscopy and circular dichroism.The enzyme activity was determined in the presence of GR-TiO2.The results of fluorescence spectroscopy revealed that the endogenous fluorescence of LYSO was quenched by GR-TiO2 and its mechanism was static quenching.The major driving forces were hydrogen bonds and van der Waals′ forces.These results of GR-TiO2 were consistent with that of nano-TiO2.The results of synchronous fluorescence and circular dichroism spectra further demonstrated that the conformation of LYSO influenced by GR-TiO2 was more than that by nano TiO2.The result of enzyme activity indicated that the enzyme activity of LYSO was inhibited more strongly by GR-TiO2.关键词：graphene-TiO2;nano-TiO2;lysozyme;spectroscopy;enzyme activity
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发布时间： - 摘要：An effective method was established for the simultaneous determination of residues of five banned amides in leather and leather products.Residual banned amides in leather and leather products were microwave assistedly extracted using methanol as extraction solvent.The extract was then purified with solid phase extraction(SPE) column，followed by the analysis of gas chromatography-tandem mass spectrometry(GC-MS/MS).The concentration of each analyte was calibrated by the external standard method.The limits of quantitation(LOQ,S/N=10) were 20，10，1，20 , 3 μg/kg for formamide，N-methylformamide，N,N-dimethylformamide，N-methylacetamide and N,N-dimethylacetamide，respectively.The average recoveries varied from 81.4% to 86.9% at three spiked concentration levels，with relative standard deviations(RSD) of 4.5%-8.7%.The proposed method was simple，rapid，accurate and sensitive，and the limits of quantitation(LOQ) were much less than the limited requirement for regulation concerning registration，evaluation，authorization and restriction of chemicals(REACH).The method could satisfy completely the demand of determination of residual banned amides in leather and leather products.关键词：microwave-assisted extraction;leather;leather product;amide;gas chromatography-tandem mass spectrometry(GC-MS/MS)
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- 2
发布时间： - 摘要：A new method,based on surfactant assisted dispersive liquid-liquid microextraction on solidification of floating organic droplets（SA-DLLME-SFO）,followed by high performance liquid chromatography（HPLC） with diode array detector（DAD） was developed for the enrichment and determination of p-nitrophenol,p-cresol,p-bromophenol and bisphenol A in environmental-water samples.1-Dodecanol was utilized as extractant in the SA-DLLME-SFO method.A conventional nonionic surfactant,Tween 20,was used as a disperser agent in this approach.Parameters affecting the extraction efficiency of the SA-DLLME-SFO method such as volume of extraction solvent and nonionic surfactant,extraction and centrifugation time,salt effect were investigated.Under the optimized conditions,the detection limits of p-nitrophenol,p-cresol,p-bromophenol and bisphenol A were 0.13,0.13,1.02,0.25 ng/mL,respectively.The calibration curves were linear in the range of 2-4 000 ng/mL for p-nitrophenol,p-cresol,bisphenol A,and 10-4 000 ng/mL for p-bromophenol.The recoveries of four compounds at spiked levels of 02 μg/mL and 0.8 μg/mL were in the range of 96.6%-105%,with relative standard deviations（RSD,n=5） of 1.9%-4.9%.The proposed method was successfully applied in the analysis of p-nitrophenol,p-cresol,p-bromophenol and bisphenol A in pond water and lake water.关键词：surfactant assisted;dispersive liquid-liquid microextraction;phenolic compounds;high performance liquid chromatography（HPLC）
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发布时间： - 摘要：A method for the rapid determination of oxytertracycline and doxycycline in plasma was established by mix mode solid phase extraction(SPE) and quaternized cellulose supported Au nanoparticles(QC-Au NPs) coated capillary electrophoresis.The QC-Au NPs were used to coat the capillary inner surface and inhibit the adsorption of analyte.The pH value of running buffer was also optimized.The result showed that the peak shape and resolution were improved，and the separation efficiency was also increased.The number of theoretical plates of oxytertracycline increased by 17.9 times as compared with that of inner bare capillary.The adsorption of oxytertracycline and doxycycline was inhibited in the capillary coated with QC-Au NPs,and their analysis could be completed in 4 min.Good linearities were obtained for oxytertracycline and doxycycline in the range of 10-200 μg/mL，with correlation coefficients of 0.997 6 and 0.995 2，respectively.The recoveries of the analytes in plasma at three spiked levels ranged from 88% to 107%，and the relative standard deviations(RSDs) ranged from 1.4%-7.7%.This method is rapid，simple and accurate，and is feasible for the determination of oxytertracycline and doxycycline in plasma samples.关键词：capillary electrophoresis;oxytertracycline;doxycycline;solid phase extraction;plasma
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发布时间： - 摘要：In this paper,the peptide hydrolysates from bovine serum albumin(BSA)hydrolyzed by 2709 alkaline proteinase were analyzed by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry,and then identified by the site-unspecified identification method of peptide mapping.The protein electrophoresis analysis indicated that all of BSA proteins were hydrolyzed by 2709 alkaline proteinase added at 0.1% level in 0.5 h,suggesting a strong proteolysis ability.The results of peptide mapping analysis indicated that the changes of peptide mapping were complex during the proteolysis process and different peptides displayed variable change features.The analysis of cleavage sites indicated that 2709 alkaline proteinase could be cleaved at almost any kind of amino acid sites,but their cleavage frequency were different.It suggested that besides broad site selectivity,2709 alkaline proteinase had a certain tendency of site selection in the proteolysis of BSA,with a significant selectivity tendency on leucine sites.The study provided a theoretic foundation for the rational use of 2709 alkaline proteinase in hydrolyzing proteins,and will help to improve the application of proteases in food industry in future.关键词：52709 alkaline proteinase;peptide mapping;mass spectrometry;hydrolyzed
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发布时间： - 摘要：1-Butyl-3-methylimidazolium chloride（［BMIM］［Cl］） ionic liquid was used as a novel electrolyte additive to prepare a prussian blue（PB） modified carbon paste electrode（ PB-IL/CPE）by electrodeposition method.The electrochemical property and kinetic characteristics of PB-IL/CPE were studied by cyclic voltammetry.The electrocatalytic reduction behavior of H2O2 on PB-IL/CPE was detected by chronoamperometry.The results demonstrated that the depositing current of PB was related to the concentration of ［BMIM］［Cl］，and the highest redox currents for PB electrodeposition were obtained at 0.2 mmol/L ［BMIM］［Cl］.Compared to PB/CPE electrode prepared in absence of ［BMIM］［Cl］，the PB-IL/CPE showed more powerful electrocatalytic reduction to H2O2，with wider linear detection range and higher sensitivity.In addition，the kinetics of PB-IL/CPE was also discussed.In comparison with that on PB/CPE，higher diffusion coefficient of K+（4.45×10-11 cm2·s-1） on PB-IL/CPE was obtained.关键词：ionic liquid;carbon paste electrode;prussian blue;electrocatalytic reduction
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- 0
发布时间： - 摘要：The interactions of loureirin A(LA)，loureirin B(LB) and cochinchinenin C(CC) with human serum albumin(HSA) under simulated physiological conditions(pH 74) were studied by pressure-mediated affinity capillary electrophoresis method(P-ACE).The binding constants were 0414×105，0252×105 ，1816×105 L/mol for LA，LB and CC，respectively.The results showed that P-ACE was a useful method to study the interaction between drug and protein.关键词：affinity capillary electrophoresis;loureirin A;loureirin B;cochinchinenin C;human serum albumin(HSA);binding constant
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发布时间： - 摘要：A poly(bromophenol-blue)-graphene(PBPB-GO) composite film modified glassy carbon electrode(GCE) was fabricated through a simple and controllable dropping and in situ electro polymerizing method，which was denoted as a DA electrochemical sensor.The result indicated that PBPB-GO composite film had a good catalytic effect on the electrochemical reduction of DA.The conductivities of bare GCE，GO/GCE，PBPB/GCE and PBPB/GO/GCE film were characterized through electrochemical impedance spectroscopy.The comparison results showed that the PBPB/GO/GCE had a lower resistance.Moreover，scanning electron microscopy was used to characterize the surface morphology of bare GO，GO/GCE and PBPB/GO/GCE，and the results indicated that PBPB-GO film had a loose and porous structure，which was beneficial to the enrichment of DA.Furthermore，the electrochemical reaction mechanism of DA on the PBPB/GO/GCE was studied and the results indicated that the electrochemical reaction of DA on the PBPB/GO/GCE was an adsorption controlled and proton participating process.The detection conditions were optimized，and the optimal electro polymerization cycles number was 15，the optimal quantity of GO(2 mg/mL) was 2 μL , and the optimal electrolyte solution was 0.1 mol/L phosphate buffer solution(pH 6.0).Under the optimal detection conditions，a wide linear range over DA concentration of 5.0×10-8-2.0×10-4 mol/L was obtained with a low detection limit of 1.0×10-8 mol/L.The DA electrochemical sensor showed good stability and reproducibility，high sensitivity and good selectivity，and was successfully applied in the detection of DA in dopamine injection.关键词：poly(bromophenol blue);graphene;glassy carbon electrode;dopamine;electrochemical sensing
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发布时间： - 摘要：A reversed phase high performance liquid chromatographic（RP-HPLC) method was developed for the determination of nodularin in hepatopancreas,kidney,muscle and plasma tissues of Carassius auratus(C-auratus) by optimizing conditions of pretreament and chromatography.Samples were extracted with 90% methanol solution by ultrasonic,followed by purification with a CNW Bond C18 solid phase extration column,and then determined by RP HPLC equipped with ultraviolet(UV) detector.The steps of purification included activating columns,sample absorbing onto columns,flushing the columns and eluting the columns.The eluent was 90% methanol containing 0.1% trifluoroacetic acid(TFA).The detection of target compound was performed with RP-HPLC using 0.1% trifluoroacetic acid(TFA)-methanol(42∶58) as mobile phase at a constant flow of 1.0 mL/min.The column temperature was set at 30 ℃ and the wavelength of UV detector was set at 238 nm while the injection volume was 20 μL.The experimental results showed that the concentration of nodularin in four crucian tissues showed good linearity(r2>0.99) with peak area in the range of 0.05-5.00 mg/L.The recoveries of nodularin from crucian tissues at three spiked concentration levels of 0.08,0.40,2.50 mg/L ranged from 79.5% to 106.4%,with RSDs of 0.54%-5.3%.The method detection limit was 11.30 μg/kg for muscle and 24.00 μg/L for plasma sample.The method was accurate and reliable,and could be applied in the dynamic distribution and residues determination of nodularin in C-auratus,providing an effective tool for the detection of nodularin in other aquatic products and for the safety control of aquatic products quality.关键词：reversed phase high performance liquid chromatography（RP HPLC);hepatopancreas;kidney;plasma;muscle;nodularin
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发布时间： - 摘要：A method for the determination solvent yellow 2 and solvent yellow 56 in dried bean curd and yuba was developed using liquid-liquid extraction-high performance liquid chromatography(LLE-HPLC).The samples were extracted by ultrasonic using hexane saturated with acetonitrile.Then，the target compounds were vortex extracted using acetonitrile saturated with hexane.The acetonitrile was moved into concentrated bottle.Operation steps were repeated for three times.The extraction solution was kept in constant volume after concentration.The concentrated solution was tested by high performance liquid chromatography.The target compounds were separated on a TC-C18(4.6 mm×250 mm，5 μm) column using water-methanol(20∶80) as mobile phase at a flow rate of 1.0 mL/min. The column temperature was set at 30 ℃,and the detection wavelength was 410 nm.Under the optimal conditions，the calibration curves of solvent yellow 2 and solvent yellow 56 were linear in the range of 0.30-50 mg/L.The limits of detection(LOD) of two targets compounds were both 0.15 mg/kg,and the limits of quantitation(LOQ) were both 0.50 mg/kg.The average spiked recoveries of two target compounds in dried bean curd and yuba were in the range of 85.4%-94.6%，with relative standard deviations(RSD，n=6) of 0.3%-2.3%.With good repeatability and high sensitivity，the method was suitable for the determination solvent yellow 2 and solvent 56 in dried bean curd and yuba samples.关键词：liquid-liquid extraction;high performance liquid chromatography(HPLC);dried bean curd;yuba;solvent yellow 2;solvent yellow 56
- 2057
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- 1126
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- 1
发布时间： - 摘要：A label-free electrochemical impedance biosensor was fabricated for adenosine detection based on a new combining mode of aptamer probes（AP） and hairpin probes（HP） in the presence of adenosine（AD）.AP was first modified on the surface of the electrode.In the presence of AD，AP was folded into hairpin structure，the loop of the hairpin hybrids with complementary loop of HP to form a“kissing aptamer complex”，through the loop-loop interactions（being similar to“kissing” behavior of the human）.Due to the steric effect of the complex，the impedance signal of the electrode was obviously increased.On the contrary，in the absence of adenosine，AP was unfolded，which was unable to combine with HP into a stable“kissing”structure.The impedance signal did not change significantly.In this study，the electron transfer resistance values before and after combination were used for the detection of adenosine.Under the optimized conditions，a good linear relationship was obtained between resistance value and logarithm of concentration of AD in the range of 5-1 000 nmol/L.The limit of detection for adenosine is as low as 0.6 nmol/L.In addition，the sensor has a good selectivity.Guanosine，cytidine and uridine did not influence the detection of adenosine.The sensor is expected to be applied in the detection of adenosine in clinical real samples.关键词：aptamer;electrochemical impedance biosensor;kissing;adenosine
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发布时间： - 摘要：A poly(L-methionine)/graphene modified glassy carbon electrode was prepared.Experiments showed that the modified electrode exhibits an obvious electrocatalytic ability for the oxidation of guanine in 0.1 mol/L phosphate buffer solution(pH 7.0).Effects of pH value and scan rate on electrochemical behaviors of guanine were investigated by cyclic voltammetry.The detection of guanine was performed by differential pulse voltammetry.The result indicated that the oxidation peak current of guanine was linear with its concentration in the range of 3.6×10-7-4.0×10-5 mol/L, with a correlation coefficient(r) of 0.990 4 and a detection limit(S/N=3) of 5.0×10-8 mol/L.The modified electrode had a good stability and reproducibility.关键词：L-methionine;graphene;modified electrode;guanine
- 1932
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发布时间： - 摘要：A novel method was developed for the determination of trace benzenes in water samples by on-line thermal desorption-gas chromatography after solid phase extraction on Fe/SiO2/PDMS particles bed column.The solid phase extraction column was prepared by filling prepared Fe/SiO2/PDMS particles into quartz tube.The adsorbed benzenes on the column was thermally desorbed and directly introduced into gas chromatography for separating and determing.Several factors affecting the extraction and separation efficiencies were investigated and optimized. Under the optimal conditions，the calibration curves of benzenes were linear in the range of 0.1-20 ng/L，with corrrelation coefficients(r) of 0.999 2-0.999 6 and detection limits(S/N=3) of 0.03-0.05 ng/L.The relative standard deviations(RSD，n=11) for 1 ng/L benzenes were in the range of 2.0%-4.4%.The presented method was sensitive and accurate，and was successfully applied in the determination of benzenes in water samples.关键词：Fe/SiO2/PDMS;benzenes;gas chromatography;electromagnetic induction heating;solid phase extraction;on line thermal desorption
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