最新刊期
      卷 30 ， 期 9 ， 2011
      • Vol. 30, Issue 9, Pages: 953-958(2011)
        摘要：Polyaniline（PAn） was synthesized by chemical oxidation using Cl-as the doping anions，and then it was packed into a porous ceramic tube as conductive stationary phase to fabricate an electrode column which was used as the working electrode of a three electrode system.A potential of-0.6 V was applied on the electrode column to make PAn in its reduction state，and thus Cl-was de doped from the PAn backbone.Cavities complementary to Cl-in three dimensional space were left in PAn to form “ion imprinted” PAn electrode column.Effects of various experimental factors on the de doping amount of Cl-were investigated， and the optimal conditions for de doping were using a potential of -0.6 V，a dedoping time of 4 000 s and a pH value of 4.0.When different mobile phases containing F-，Cl-，Br-，SO2-4and H2PO-4 flew through the electrode column，a potential of +0.6 V was applied on this column.The different kinds of anions in the mobile phases were doped into the PAn backbone because of the reversible doping/de doping property of PAn.The “Cl-imprinted” PAn electrode column has the maximum affinity to Cl-based on the mechanism of molecular imprinting，and its affinity to the other anions decreased with the increase of the anions radii.The cyclic voltammograms of the “ion imprinted” PAn in electrolytes containing different anions also showed a similar trend.Therefore，PAn was expected to be used as the stationary phase controlled by electrochemistry.  
        关键词：potential modulation;ion imprinted;polyaniline;electrode column;analysis of anion   
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      • Vol. 30, Issue 9, Pages: 959-963(2011)
        摘要：The interaction between naproxen and cyclodextrin was studied by two-dimensional diffusion ordered（2D-DOSY) NMR spectroscopy.Influences of different factors on the self-diffusion coefficient and the equilibrium constant were investigated.The results showed that the increase of temperature,water content,pH and ionic strength had more influence on the self-diffusion coefficient of the guest than that of the host，which could increase the equilibrium constants.The inclusion interaction was the strongest in a solution of pH 9.0.The results of thermodynamic analysis showed that the inclusion process was spontaneous and endothermic entropy-driven process,and the main active force was the hydrophobic force.  
        关键词：diffusion ordered NMR spectroscopy（DOSY);self-diffusion;naproxen;β CD;inclusion interaction   
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      • Vol. 30, Issue 9, Pages: 964-968(2011)
        摘要：A chemical vapor generation（CVG） and inductively coupled plasma mass spectrometric （ICP MS） method was proposed for the simultaneous determination of ultra-trace level of As,Sb,Bi,Ge,Sn,and Hg in coastal and estuarine seawater.Effects of operating parameters,including concentrations of KBH4,HCl and thiourea,pump flow rate and carrier gas flow rate on analytical performance were studied.The results showed that good signal to noise（S/N） ratios for all the analysed elements were obtained when 0.70% HCl,0.10 g/L thiourea,11.0 g/L KBH4,and 0.40 L/min carrier gas were used in the CVG procedure.The relative standard deviations（RSDs,n=5） for 0.10 μg/L spiked sample were in the range of 3.9%-8.9%.The spiked recoveries for the seawater samples were between 89% and 112%.The method blanks were in the range of 0.012-0.036 μg/L.The limits of quantitation（LOQs,10σ） for the developed method were obtained between 0.006 7 μg/L and 0.026 μg/L.The method could be applied in the simultaneous determination of As,Sb,Bi,Ge,Sn and Hg in coastal and estuarine seawater.  
        关键词：chemical vapor generation;inductively coupled plasma mass spectrometry;coastal and estuarine seawater;ultra-trace level;element   
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      • Vol. 30, Issue 9, Pages: 969-975(2011)
        摘要：A high performance liquid chromatography tandem mass spectrometric（HPLC-MS/MS） method was developed for the simultaneous determination of 8 penicillins（e.g.amoxicillin,ampicillin,penicillin G,penicillin V,oxacillin,cloxacillin,nafcillin and dicloxacillin） residues in fishery products．The penicillin G-D7,as an internal standard,was added into the sample before the extraction.The samples were extracted with acetonitrile-water（80∶20，by volume），and then cleaned up by dispersive solid-phase extraction with C18 dispersant sorbent and filtered through a Mr 10000 cut-off ultrafree microcentrifuge filter.The separation of 8 penicillins were performed on a HyPURITY C18 （2.1 mm×150 mm，3.5 μm） column using a mixture of 0.1% formic acid and acetonitrile containing 0.1% formic acid as mobile phase.The qualitative and quantitative analysis for the analyte were carried out under the selective reaction monitoring（SRM） mode with positive electrospay ionization．Under the optimal conditions,the calibration curves were linear in the range of 1.0-50.0 μg/L for ampicillin，penicillin G and nafcillin,2.5-100.0 μg/L for penicillin V,oxacillin,cloxacillin and dicloxacillin,and 5.0-200.0 μg/L for amoxicillin,respectively,with detection limits of 0.6 μg/kg,1.5 μg/kg and 3.0 μg/kg,respectively.The average spiked recoveries for 8 penicillins were between 74%and 98% with relative standard deviations（RSDs）less than 10%．The proposed method is accurate，sensitive and high-efficient,and is applicable for the determination of penicillins in fishery products．  
        关键词：high performance liquid chromatography tandem mass spectrometry（HPLC-MS/MS）;fishery products;penicillins;dispersive solid-phase extraction   
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      • Vol. 30, Issue 9, Pages: 976-982(2011)
        摘要：The single-walled carbon nanotubes with carboxyl modified glassy carbon electrode（SWCNTs-COOH/GCE） was prepared.The prepared electrode films were characterized by scanning electron microscopy（SEM） and electrochemical impedance spectroscopy（EIS） method.The SEM results showed that SWCNTs-COOH/GCE electrode was coated with a film of nano structure of intricate network through homogeneous distribution of SWCNTs-COOH in anhydrous ethyl alcohol solution.The EIS results showed that SWCNTs-COOH/GCE electrode had a good electrocatalytic response to the electron transfer of ［Fe（CN）6］3-/4-.The electrochemical behavior of troxerutin was studied by cyclic voltammetry（CV）.The result indicated that the SWCNTs-COOH/GCE electrode exhibited a remarkable catalytic and enhanced effect on the current response of troxerutin.The electrode reaction was a process of one-electron and one-proton transfer,and its oxidation mechanization may attribute to the oxidation of phenolic hydroxyl from troxerutin to carboxyl based on the product of constant electrolyte-voltage oxidation of troxerutin.The diffusion coefficient（D） was 1.10×10-6 cm2?s-1 and the rate constant（k） was 9.87×10-3 mol?L-1?s-1.Under the optimum condition,the response of the peak（E=0.85 V） was proportional to the troxerutin concentration in the range of 8.04×10-7-6.41×10-4 mol?L-1 with a detection limit of 5.01×10-7 mol?L-1.The RSDs（n=10） of troxerutin were 3.1%.The method was applied in the determination of troxerutin in real sample with satisfactory result.  
        关键词：SWCNTs-COOH;chemically modified electrode;troxerutin;cyclic voltammetry（CV）;electrocatalytic oxidation   
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      • Vol. 30, Issue 9, Pages: 983-989(2011)
        摘要：The thermal decomposition behaviors of chlorogenic acid at different atmospheres and the content distribution of phenol in its pyrolysis products were investigated by thermogravimetry（TGA）and pyrolysis gas chromatography/mass spectrometry（Py/GC-MS）.The major mass loss temperature zone was obtained by thermal gravimetric analysis at nitrogen atmosphere,and the pyrolysis reaction of chlorogenic acid was investigated under inert（helium）and aerobic atmospheres（the nitrogen-oxygen mixture containing 9%oxygen）,respectively,at four typical temperature points selected from the major mass loss temperature zone,together with the other three points chosen from the high temperature combustion zone when a cigarette was ignited.The results indicated that the pyrolysis product in the presence of helium or nitrogen-oxygen mixture did not show any significantly difference,but the product sorts in nitrogen-oxygen mixture were a few more than those in helium with the increase of temperature.The relative content of the main pyrolysis product,phenol did not changed specially except at 300 ℃ and aerobic atmosphere.The major mass loss temperature zone was divided into five temperature ranges by an interval of 100 ℃.In each temperature range,the evolved gas was absorbed by 10 mL 1% acetic acid solution and then analyzed by HPLC.The results indicated that the main pyrolysis product of chlorogenic acid was phenol.Furthermore,the pyrolysis content of phenol changed with the varication of the temperature.This study provided a reference for the analysis of pyrolysis of tobacco ingredients in cigarette burnning.  
        关键词：chlorogenic acid;pyrolysis/GC-MS;thermogravimetry;phenol   
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      • Vol. 30, Issue 9, Pages: 990-995(2011)
        摘要：A multiresidue method was developed for the simutaneous determination of 19 pesticides in tea by LC-MS/MS. The ionisation mode used was positive mode with multiple reaction monitoring．The one precursor/two product ion transitions were used for each neonicotinoids． The procedure，based on QuEChERS prior to the determination by UPLC-MS/MS，was validated based on the SANCO European Guidelines with satisfactory spiked recovery （68%–105%） and measurement uncertainty （≤20%）. The results showed that the calibration curves were linear in the range of 1-15 μg/L for 18 analytes and 5-75 μg/L for difulubenzuron．The limits of quantitation （LOQ） were 50 μg?kg-1 for difulubenzuron and 10 μg?kg-1 for the other 18 pesticides. The method was simple，rapid and accurate，and could meet the requirement of the maximum residue limits （MRLs） for pesticides in tea as recommended by the European Union.  
        关键词：tea;multiresidue analysis;QuEChERS;LC-MS/MS   
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      • Vol. 30, Issue 9, Pages: 996-1000(2011)
        摘要：Field-amplified sample injection and sweeping-micellar electrokinetic chromatography（FASI-sweeping MEKC） was used in the simultaneous separation and determination of caffeic acid and chlorogenic acid in honeysuckle.Effects of experimental conditions,such as concentration of SDS,injection voltage,injection time ratio of water to sample,injection time,composition and concentration of background electrolyte on separation efficiency were optimized.The optimal conditions were as follows:separation column:an uncoated fused silica capillary column（50 cm×50 μm,effective length 33 cm）,background electrolyte:100 mmol/L sodium dodecyl sulfate（SDS）-20 mmol/L NaH2PO4（pH 2.2）-15% acetonitrile,temperature:25 ℃,detection wavelength:215 nm,sample injection voltage:-10 kV,separation voltage:-20 kV,sample injection time:15 s,water injection time:195 s（H=20.0 cm）.Under the optimum conditions,the separation of the two organic acids was performed for 15 min with RSDs of peak area less than 4%.The calibration curves showed good linearities in the ranges of 29.4-470.4 μg/L for caffeic acid and 48.5-776 μg/L for chlorogenic acid with detection limits（S/N=3）of 1.12 μg/L and 2.18 μg/L,respectively.The spiked recoveries were in the range of 98%-106% and 96%-106%,respectively.  
        关键词：field-amplified sample injection（FASI）;sweeping-micellar electrokinetic chromatography（sweeping-MEKC）;honeysuckle;caffeic acid;chlorogenic acid   
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      • Vol. 30, Issue 9, Pages: 1001-1005(2011)
        摘要：A method was developed for the determination of organochlorine pesticide residues in Chinese herbal tea granule by accelerated solvent extraction combined with gas chromatography-negative chemical ionization-mass spectrometry(ASE/GC-NCI-MS)The samples were extracted with ASE for 10 min×3 times using hexane-dichloromethane(1∶1) as solvent at temperature of 100 ℃ and pressure of 10 MPa.The extracts were purified by solid phase extraction using a SampliQ Silica column,concentrated with a gentle stream of nitrogen,and then separated on a DB-1MS column(30 m×0.25 mm× 0.1 μm).The quantitative analysis of 25 organochlorine pesticides was carried out by GC-NCI-MS under selected ion monitoring mode.The calibration curves of 25 organochlorine pesticides were linear in the range of 1-500 pg,with correlation coefficients more than 0.999.The limits of detection and limits of quantitation were in the ranges of 1.0-34.4 pg/g and 3.4-114.6 pg/g,respectively.The spiked recoveries ranged from 86% to 105%.The method was applied in the determination of the Chinese herbal tea granule samples with different batches from different manufactures,and none of the 25 organochlorine pesticides was detected.The method was sensitive and efficient,and could meet the requirement for the quality control of organochlorine pesticide residues in Chinese herbal tea granule.  
        关键词：Chinese herbal tea;organochlorine pesticide;gas chromatography-negative chemical ionization-mass spectrometry;accelerated solvent extraction;residue   
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      • Vol. 30, Issue 9, Pages: 1006-1012(2011)
        摘要：An investigation was carried out for the impact of two pretreatment methods on the matrix effect of Epimedium-derived flavonoid compounds in rabbit serum by liquid chromatography-tandem mass spectrometry（LC-MS/MS）.Before and after the pretreatment of rabbit blank serum via the extractions of ethyl acetate（liquid-liquid extraction,LLE）and C18 cartridge（solid phase extraction,SPE） respectively,a certain concentration solution of mixed reference substances containing four Epimedium-derived flavonoid compounds（icariin,icariside Ⅰ,icariside Ⅱ and iicaritin） was added exactly,and LC-MS/MS was adopted for sample analysis.Then,the absolute matrix effects,the recoveries and the process efficiencies of Epimedium-derived flavonoid compounds in rabbit serum were evaluated.The result showed that,after the sample pretreatment of LLE with ethyl acetate,the absolute matrix effects of Epimedium derived flavonoid compounds in rabbit serum were more than 100%,the recoveries and the process efficiencies were much higher and stable,while after the sample pretreatment of SPE with C18 cartridge,the absolute matrix effects of Epimedium derived flavonoid compounds in rabbit serum were less than 100%,the recoveries and the process efficiencies were much lower and unstable.The above results indicated that ionization enhancement can be realized for LC-MS/MS analysis of Epimedium-derived flavonoid compounds in rabbit serum while the recoveriesand the process efficiencies of Epimedium-derived flavonoid compounds were much higher and more stable when using ethyl acetate for sample pretreatment,and this pretreatment method was also suitable for the pharmacokinetic study of Epimedium-derived flavonoid glycosides in rabbits as the serum sample pretreatment.  
        关键词：LC-MS/MS;matrix effect;Epimedium-derived flavonoids;rabbit serum;liquid-liquid extraction;solid phase extraction   
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      • Vol. 30, Issue 9, Pages: 1013-1017(2011)
        摘要：The ceftiofur artificial antigen was synthesized by conjugating ceftiofur to BSA with n hydroxysuccinimide and N,N dicyclohexyl carbodiimide.The synthesis product was characterized by the traditional sodium lauryl sulfate-polyacrylamide gel electrophoresis（SDS-PAGE） and electrospray ionization mass spectrometric（ESI MS） method.The result showed that the ceftiofur artificial bovine serum albumin antigen was succesfully prepared and the binary complex ratio of ceftiofur to BSA was about 8.Herein,atomic force microscope（AFM） was firstly used to characterize the ceftiofur artificial antigen.  
        关键词：ceftiofur;artificial antigen;atomic force microscope(AFM)   
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      • Vol. 30, Issue 9, Pages: 1018-1022(2011)
        摘要：A quick and simple analytical method was developed for the determination of clenbuterol and chloramphenicol residues in pig urine using dispersive liquid-liquid microextraction combined with high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.5 mL pig urine with pH adjusted to 10.0 was added with 5 ng clenbuterol-D9，5 ng chloramphenicol-D5 and 10% NaCl before extraction.Then the urine sample was added with the mixture of 250 μL chloroform and 750 μL isopropanol for dispersive liquid-liquid microextraction.After centrifugation,the sediment was transferred and dried under a gentle nitrogen flow,then redissolved with methanol-water solution.The clenbuterol and chloramphenicol in pig urine was simultaneously determined by HPLC-MS/MS under positive and negative transferring mode with the internal standard method.The spiked recoveries ranged from 82% to 97% at fortification levels of 0.05-2 μg/L for clenbuterol and 0.1-2 μg/L for chloramphenicol,with relative standard deviations of 6.8%-9.6%.The limits of quantitation（LOQs） were 0.05 μg/L for clenbuterol and 0.1 μg/L for chloramphenicol,respectively.With the advantages of convinience,sensitivity,good recoveries and repeatability,the method was suitable for the detection of clenbuterol and chloramphenicol residues in pig urine.  
        关键词：dispersive liquid-liquid microextraction;high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）;pig urine;clenbuterol;chloramphenicol   
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      • Vol. 30, Issue 9, Pages: 1023-1027(2011)
        摘要：A high performance liquid chromatographic(HPLC) method was developed for the determination of antioxidant D in pressure sensitive adhesive and its products．The sample was dissolved with ethyl acetate，then precipitated by methanol.The extract was centrifugally separated for 5 min at a speed of 3 000 r/min．After filtrated with filter membrane，the supernatant was separated on a C18 column by isocratic elution using acetonitrile-water as mobile phase at a flow rate of 0.5 mL/min，and determined by HPLC with diode-array detector(DAD)at 310 nm，quantified by the external standard method．The conditions of sample pretreatment and chromatographic separation were optimized，and the confirmatory method of mass spectrometry used to quantitatively determine antioxidant D in the sample was established．Under the optimal conditions，the method showed good linearities between peak areas and the contents in the ranges of 0.01-1 mg/L and 1-100 mg/L for antioxidant D，with a limit of quantitation of 1 mg/kg．The established method was applied in the determination of antioxidant D in emulsion-type pressure-sensitive adhesive，hotmelt-type pressure-sensitive adhesive and solvent-type pressure-sensitive adhesive，and the spiked recoveries ranged from 96% to 100% with relative standard deviations(RSDs) of 1.1%- 3.1%．The results indicated that this method was reliable，sensitive and repeatable，and could meet the requirement for analysis of antioxidant D in the pressure sensitive adhesive and its products.  
        关键词：antioxidant D;pressure-sensitive adhesive;high performance liquid chromatography   
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      • Vol. 30, Issue 9, Pages: 1028-1032(2011)
        摘要：A high performance liquid chromatographic(HPLC) method was established for the simultaneous determination of trans,trans-muconic acid(tt-MA)，hippuric acid(HA)，mandelic acid(MA)，phenylglyoxy acid(PGA)，p-aminophenol(PAP)and p-nitrophenol(PNP)in urine．The chromatographic separation and the detection conditions were optimized，and a programmed gradient which the wavelength was changed with the time was applied for the detection．The optimal pretreatment conditions for the sample were as follows:extraction solvent: 5 mL dichloromethane-isopropanol(7∶3)，sample volume:5 mL，NaCl:0.75 g，extraction time:2 min．The sample was firstly extracted under acidic condition，and repeated once under the neutral condition，then the two extraction liquids were merged．The extract liquor was volatilized to dryness in water bath with the volatilization temperature less than 70 ℃，then redissolved with 1.0 mL mobile phase.Under the optimal conditions， the linear ranges of the six components were up to 103，and the correlation coefficients(r) were not less than 0.999 3．The detection limits(S/N=3) were in the range of 3-30 μg/L．The spiked recoveries were in the range of 86%- 104% with relative standard deviations less than 5%．The method was sensitive，accurate and rapid，and could meet the needs of biological monitoring on the metabolites of harmful substances in urine.  
        关键词：HPLC;urine;metabolite;liquid-liquid extraction   
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      • Vol. 30, Issue 9, Pages: 1033-1038(2011)
        摘要：A simple and reliable method was developed for the electrochemical determination of nitrite based on glassy carbon electrode(GCE) modified with Au nanoparticles(AuNPs)encapsulated in dendrimers．Firstly，chitosan(Chit) was modified on the GCE，and in the presence of coupling agent carbodiimide，carboxyl-terminated poly(amidoamine)(generation 4.5) dendrimers were covalently attached onto chitosan through the formation of amide bonds between carboxylic acid groups of the dendrimer and amine groups of chitosan．The Au(Ⅲ) ions were coordinated in the interior of dendrimer with nitrogen ligands and then reduced to form AuNPs，which was written as Den(AuNPs)/Chit/GC electrode．The Den(AuNPs)/Chit/GC electrodes were characterized with cyclic voltammetry(CV)，electrochemical impedance spectroscopy(EIS)．The experimental results showed that the present Den(AuNPs)/Chit/GC electrodes have excellent sensitivity for nitrite determination．The chronoamperometric studies revealed that the amperometric response was rapid and stable，and offered a linear dependence over the ranges of nitrite concentrations from 2 μmol/L to 20 μmol/L and 0.07 mmol/L to 1.12 mmol/L with a limit of detection(S/N=3) down to 1.0 μmol/L．The method was applied in the determination of nitrite in real sample with satisfactory result．Den(AuNPs)/Chit/GC electrodes are to provide a nanostructured platform for the development of electrochemical sensors and biosensors.  
        关键词：dendrimers;chitosan;Au nanoparticles(AuNPs);electrochemical;nitrite   
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      • Vol. 30, Issue 9, Pages: 1039-1043(2011)
        摘要：The interaction between guanidine chloride and bovine serum albumin（BSA） in aqueous solution as well as the denaturation process of BSA were studied with fluorescence spectroscopy at 30 ℃ and two pHs.The fluorescence spectroscopic data were analyzed with the methods described by Pace.The unfolding fraction（fu）,denaturation equilibrium constant（Ku） and free energy of unfolding（ΔGu）of protein were calculated.The transition midpoint（c1/2） ,steepness of the transition region（m） and free energy of unfolding（ΔGH2O） were also obtained.The results indicated that the denaturation of BSA was induced by guanidine chloride through direct and indirect effects,the interaction between guanidine chloride and BSA was divided into three stages.When the guanidine chloride concentrations reached 60 mol?L-1,the unfolded fraction fu was about 1 and the BSA was completely denaturated.  
        关键词：fluorescence spectroscopy;bovine serum albumin;guanidine chloride;denaturatio   
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      • Vol. 30, Issue 9, Pages: 1044-1049(2011)
        摘要：Preparative high-speed counter-current chromatography（HSCCC） and high performance liquid chromatography（HPLC） were employed firstly to separate chemical compounds in Vitex negundo L.. The procedure was performed in a two phase solvent system of chloroform-methanol-water （4∶3∶2,by volume） at a flow rate of 2.0 mL?min-1 by normal phase elution,in which the upper phase was the stationary phase and the lower phase was the mobile phase.The sample concentration was 20 g?L-1,while the rotation speed was 850 r?min-1 and the eluate was detected at 254 nm.Five compounds were obtained from the crude extract of the plant in a simultaneous process,which,according to their physical and chemical properties,were identified as:vitexin（Ⅰ）,casticin（Ⅱ）,3,5-di-O-caffeylquinic acid（Ⅵ）,luteolin（Ⅶ）,luteolin-7-O-β-D-glucoside（Ⅷ）.The purities of the five compounds were 98.0%,92.3%,96.8%,97.4%and 90.3%,respectively.  
        关键词：High-speed counter-current chromatography;Vitex negundo L.;high performance liquid chromatography;chemical composition;separation   
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      • Vol. 30, Issue 9, Pages: 1050-1054(2011)
        摘要：A gas chromatographic（GC） method was established for the analysis of a potential greenhouse gas，nitrous oxide（N2O） in wastewater treatment.The optimum conditions of chromatography were determined by a series of parallel tests.The working temperatures of the injector，column and electron capture detector（ECD） were 105，100 and 300 ℃，respectively；95% Ar +5% CH4 was selected as the carrier gas；the column flow and the makeup gas flow were 25 mL/min and 50 mL/min，respectively.Under the optimal conditions，the calibration curve was linear in the range of 0.255-100 mg/L N2O，with correlation coefficient higher than 0.999 and the mean recovery larger than 90%.When detecting 100 mg/L N2O（standard samples） using direct injection and headspace methods，the relative standard deviation（RSD） values were 1.5% and 0.32%，respectively，and the recoveries were both over 90%.The method was successfully applied in the determination of N2O in wastewater treatment processes and the detected values are consistent with the results reported in literatures.This method is simple，sensitive and repeatable.  
        关键词：nitrous oxide;gas chromatography;electron capture detector;temperature;carrier gas;sensitivity   
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      • Vol. 30, Issue 9, Pages: 1055-1058(2011)
        摘要：A gas chromatographic method was developed for the determination of free glycerol in crude glycerine without any derivative pretreatment.The sample was resolved with THF-water（3∶1）mixed solvents using diethylene glycol diethyl ether as internal standard,and was directly separated on an HP-5 column（30 m×0.32 mm×0.25 μm）.The influences of some important factors,such as solvent,internal standard,capillary column and injection volume were investigated.Under the optimal conditions,the standard curve of glycerol was linear in the concentration range of 0 -20 g/L,with correlation coefficient of 0.999 94.The relative standard deviations（RSDs,n=8） were in the range of 0.68%-0.91%.The spiked recoveries at three concentration levels ranged from 95% to 105%.Neither solvent nor internal standard applied in this method made chemical reaction with the ingredients of crude glycerine sample.This method was simple,rapid and accurate,and was suitable for the quantitative analysis of glycerol content in crude glycerine.  
        关键词：crude glycerine;free glycerol;gas chromatography   
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      • Vol. 30, Issue 9, Pages: 1059-1062(2011)
        摘要：The fat-soluble components of four rice species,including Wuchang rice,Meihe rice,Liaoning rice and Thailand rice,were analyzed by GC-MS method. By means of NIST mass spectral library and NIST mass spectral search program,four main fat-soluble contents such as palmitic acid,9,12-octadecadienoic acid,oleic acid,squalene and sitosterol in the rices were recognized.The fat-soluble components fingerprints were established for different rice species. The results indicated that there were diverse fingerprints for the rices from different places of origin. Therefore,an effective method was established for the identification of different rice species by using principal component analysis and hierarchical cluster analysis.  
        关键词：GC-MS;fingerprints;principal component analysis;hierarchical cluster analysis;rice   
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      • Vol. 30, Issue 9, Pages: 1063-1066(2011)
        摘要：A gradient elution/ion exchange chromatographic method was developed for the simultaneous determination of lactic acid，acetic acid，DL malic acid，malonic acid，maleic acid，oxalic acid，citric acid and DL-isocitric acid trisodium salt in fruit juice.0.8-30 mmol/L KOH was produced with an EG40 eluent autogenerator.Eight organic acids were separated on an IonPac AS11-HC column and an IonPac AG11-HC guard column，and detected with suppressed conductivity detector under the self-regenerating suppressor mode．The gradient elution conditions were optimized．Under the optimal conditions,eight organic acids were successfully separated and good linear relationships were obtained between peak area and mass concentration in the measurement ranges．The detection limits were in the range of 10-30 μg/L,and the average recoveries were 95%-100% with RSDs（n=6） less than 3.0%.The method was simple and was applied in determination of eight organic acids in fruit juice samples with good precision and accuracy.The method could be used to evaluate the quality of fruit juice by developing fingerprint chromatograph of squeezing fresh fruit juice.  
        关键词：ion exchange chromatography;eluent autogeneration;organic acids;fruit juice   
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      • Vol. 30, Issue 9, Pages: 1067-1073(2011)
        摘要：The latest progress of electrophoresis on microfluidic chips(EMC)is reviewed in this article.The preparation mechanisms，surface modifications and properties of different materials in EMC are compared.The sampling，separation and detection systems of EMC with different structures，as well as their applications in analysis of fluorescent substance，metallic ion，sugar，medicine，nucleic acid，DNA，amino acid，polypeptide and protein，are summarized.The future development of EMC is also forecasted.  
        关键词：electrophoresis on microfluidic chips;microfluidic channel;surface modification;microfabrication   
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      • Vol. 30, Issue 9, Pages: 1074-1078(2011)
        摘要：As a new composite material， poly（dimethylsiloxane）-gold nanoparticles (PDMS-AuNPs) composite with dual merits of PDMS and gold nanoparticles has been widely applied in the fields of biosensing，biofunctional materials，environmental protection and microfluidics.In this paper，two main methods for the preparation of PDMS-AuNPs composite in common chemical laboratories and its applications in biosensing were reviewed.The development and application prospect of PDMS-AuNPs composite was put forward.  
        关键词：PDMS-AuNPs;biosensing;biofunctional material;review   
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