【doc】管内固相微萃取-气相色谱法在线联用技术用于水样中的痕量分析

【doc】管内固相微萃取-气相色谱法在线联用技术用于水样中的痕量分析 管内固相微萃取-气相色谱法在线联用技术 用于水样中的痕量分析 2004年7月 July2004 色谱 ChineseJournalofChromatography Vo1.22No.4 354,357 On?-LineCouplingofIn?-TubeSolidPhaseMicroextractionto CapillaryGasChromatographyforTrace AnalysisofAqueousSamples GUANYafeng,WANGHanwen,LIUWenmin (DepartmentofAnalyticalChemistry&Micro—Instrumentation.DalianInstituteofChemicalPhysics, TheChineseAcademyofSciences.Dallan,,6012.China) Keywords:in—tubemicroextraction;solidphasemicroextraction;on—lineextraction;samplepretreatment; capillarygaschromatography CLCnumber:0658Documentcode:AArticleIC:l000—87l3(2004)04—0354—04 Sincethedevelopmentofsolidphasemicro— extraction(SPME)method,manymodifica— tionshavebeenmadetoimprovetheavailability andapplicationofthetechnique一.Thein—tube SPME(ITSPME)wasemergedandemployedin highperformanceliquidchromatography(HPLC) asanefficientandsimplepreparationmethod, whichoffersseveraladvantagesoverthefiber SPMEsyringe.TheITSPMEshouldpreserve theadvantagesofSPME,andcouldofferhigher enrichmentfactor,betterquantitation,andauto— mationthroughanon—linecouplingwithachro— matograph. On?lineextraction?capillarygaschromatogra— phy(CGC)isanattractivemethodfortheanaly— sisofaqueoussamples.Anopen—tubulartrapping columnforon.-lineextraction—capillarygaschro?- matographyintheanalysisofaqueoussamples wasreported.Inthatstudy,twoswitching valvesandanorganicsolventwereusedforde— sorption.However,thedisadVantagesofdead volumeandsorptivesitesinswitchingvalveespe— ciallyduringtheprocessofthermaldesorption, leadstopoorerreproducibilityinquantitationof traceanalysisbecauseofthesorptiveeffectsof valves,metalconnectionsandtubing. AnotherprobleminITSPMEforwatersample isthehydrophobicpropertyofthesolidphase. UnlikefiberSPMEwhereastirisusedtodistu【rb thewatersampleandremovethethinfilmofair betweenthesolidphaseandwatermatrixduring extraction,thewaterstreamintheopen—tubular isinlaminarflowcondition.Thisfilmnotonly Receiveddate:2004-04-05 Correspondingauthor:GUANYafeng prohibitsthetransportationofanalytesfromwater matrixtothesolidphase.butalsoinfluencesthe equilibriumconstantbecauseoftheinterference ofairlayer. ThepresentpaperreportsanovelITSPME devicecoupledon.1inewithCGCforthedetermi?- nationofcontaminantsinwater.Theextractor isconnectedtoatransferlinethroughamicroT— pieceafteravalve,permittingthetransferof thermal—desorbedcomponentsdirectlyintoGCin— steadofthroughavalve.Highsampleflowrate andvacuumareemployedduringtheextractionin ordertoimprovethecontactbetweenthesample andthesolidphase,leadingtofasterequilibrium, higherenrichmentfactor,andbetterreproduc? ibility.Theoperatingprincipleandtheconfigura- tionofthedevicemakeitpossibleforautoma— tion 1On—lineITSPMEinstrumentset-up Theon—lineITSPMEdeviceisschematically depictedinFig.1.Ahomemadeheatingcaseca— pableofheatinguptomorethan320?atarate of290?/minprovidesafastheatingforthecap— illaryextractor.Aretentiongapwasconnected beforetheanalyticalcolumnforbetterfocusingof thedesorbedsamples. 2Resultsanddiscussion 2.1Evaluationofon?lineITSPMEcoupled withCGC ComparedwiththefiberSPME,thecapillary extractorhasl0timesmoresolidphaseandabout 第4期GUANYafengetal:On—LineCouplingofIn—TubeSolidPhaseMicroextractionto CapillaryGasChromatographyforTraceAnalysisofAqueousSamples'355' AuxiliarygasA AuxiliarygasB AuxiliarygasC Fig.1Schematicdiagramoftheon-lineITSPMEcoupledwithCGCsystem 1.six— portvalve:2.flowcontrollerAforsampling:3.flowcontrollerBfordesorptiongas:4.flowcon trollerCforauxiliarygas:5 samplevial;6.mini-watercircularvacuumpump;7,micro一 "T"piece;8,transfercapillary;9.capillaryextractor;l0,pre—column:11 press—fitormicro-union:l2.analyticalcolumn:l3.on—columninjection. 800timesmoreexchangingsurface,whichresults indrasticincreaseoftheextractionefficiencyand enrichmentfactor.Aqueoussamplescontaininga seriesofalkanes(Cl0一Cl9)atl0g/Llevel wereemployedtoevaluatetheapparatus.There— suitsaredemonstratedinFig.2.Theextracted analytesfromthesamesample(15mLaqueous sample)byITSPMEin2.5minwasaboutthirty— timemorethanthatoffiberSPMEin35min,as showninFig.2-aandFig.2-b.Theenrichment factorofITSPME(extractionfor40min)wasa— boutfifty?foldhigherthanthatoffiberSPME(ex— tractionfor35min)evenforcompoundswithlow concentration(2g/L).Thebaselinesofchro一 吾400 < 200 0 000 800 600 200 0 4678910 ,/inii1 matogramsfromin—tubeSPMEareverysmooth becausethecapillaryextractorshavethinnerand strongerfilmofbondedphase,whileghostpeaks normallyexistinfiberSPME.Underoptimalcon— ditions,thelimitofdetection(LOD)for一C.R was0.012g/L,muchlowerthanthatofthefi— berSPME(LOD3g/L). Sixreplicateexperimentsofon--lineextrac-- tion/desorption/detectionwereperformedtoex. aminethereproducibility.Theprecision(=5) obtainedvariedbetween5%and15%(RSD).de— pendingonthealkanesandconcentrationsstudied. Wedeterminedthelinearitybyextracting spikedaqueoussampleswithconcentrationsran一 90 8O 70 60 50 40 30 80 70 60 5O 40 30 一 b /一 \/ .上' 46789l0 t/min Fig.2Comparisonofchromatogramsofspikedaqueoussamplesbyon—lineITSPMEandfiberSPME aextractionofl5mLsamplein2.5minbyon—lineITSPME:b.extractionof15mLsamplein35minbyfiberSPME;c.extraction of300niLsamplesin40minwithalkanesat2~tg/Llevelbyon—lineITSPME;dextractionof15mLsamplesin3minwithalkanesat10 g/LlevelbyfiberSPME.Peakidentifications:ll,f-C;2.他一Cl:3n—Cl4:4n'CI5;5.一Cl6;6.n—Cl7;7-n—ClH;8-n—Cl9. ? 356?色谱 gingfrom0.1g/Lto100g/L.Themethodwas linearoveratleast3ordersofmagnitude.Theco— efficientofcorrelationachievedwasbetterthan 0.99.Inaddition,wedidnotfindanycarryover or"memoryeffects"withthison—lineITSPME— CGCsystem. :50 OO 50 :50 200 <150 00 第22卷 2.2Determinationofpolycylicaromatichy? drocarbons(PAHs)withon?lineITSPME? CGC.FID SixteenstandardsofPAHswerespikedin wateratg/Lorsub一g/Llevels,andwerede— terminedasshowninFig.3. 4684l6l82O222426 Fig.3On.1ineITSPME—CGC—FIDchromatogramofaqueoussamplesspikedwithPAHs ainWahaha0purifiedwaterfordrinking:bintapwaterPeakidentifications:1naphthaleneI2p ~g/L);2acenaphthylene(2 LLg/L);3.acenaphthene(2g/L);4fluorine(0.2g/L),5phenathrene(02g/L);6.anthracene(0. 2p~g/L);7.fluoranthene (02g/L);8pyrene(02p~g/L):9.benzo[n]anthracene(02p~g/L);10.chrysene(0.2p~g/L);11.benzo[b]fluoranthene(0?2 LLg/L);l2benzo[k]fluoranthene(02p~g/L);13benzo[0]pyrene(02p~g/L);14.indeno[1,2,3-cd]pyrene(0.2p~g/L);15? dibenzo[?,h]anthracene(02g/L);l6benzo[g,h,i]pewlene(0.2p~g/L);17hexachlorocyclopentadiene;18.diethylphthalate; l9.N.nitrosodiphenylamine:20.di—H+butylphthalate;2lbutyl—benzylphthalate. 2.3Determinationofchlorinatedpesticides withon.1ineITSPME.CGC.ECD Twenty—sixstandardsweredividedtothree groups,andeachcompoundwasspikedin30mLof > 500 40(1 300 200 () 0 t/n1II1 20() 50 waterat0.25L.Thechromatogramsareshown inFig.4.ThepeaksofP,P一dichlorodiphenyl—trichlo— roethane(PP一DDT)andiprodionewerequitegood. Thelowestdetectionlimitformostofthemwas 0 t/n1in 2() 300 >200 三 00 0 0152025 tmin Fig.4On.1ineITSPME—CGC—ECDchromatogramsofaqueoussamplesspikedwithchlorinatedpesticides Peakidentifications:1"BHC:2口一BHC;36-BHC;4op—DDE;5PP一DDE;6.op—DDD;7.PP一DDD;8.PP一DDT;9iprodione 10lidane:11.pentachloronitrobenzene;12vinclozolin;13keithane;14.op—DDT;15cyhalothrinlambda;16dicloran;17fen propathrin;18eis—permethrin;19,r?,is—permethrin;20f'一fenvalerate;21,lr『Jns— fenvalerate;22fis-deltan1ethrin;23,lrrJHs'delta methrin. 第4期 GUANYafengetal:On—LineCouplingofIn—TubeSolidPhaseMicroextractionto CapillaryGasChromatographyforTraceAnalysisofAqueousSamples'357' about0.05L,andsub—pg/Lforcomponents suchasbenzenehexachlorides(of一,一.占一BHC). 2.4Determinationofphosphoruscontaining pesticideswithon-lineITSPME-CGC.PFPD Sixteenstandardswerespikedin30mLaque— OUSsampleat0.5g/Leach.Thechromatogram isshowninFig.5.Thelowestdetectionlimitwas 0.05g/L. 11.1 I_l7 l I"8——1—L—一 4h ,iiiil] 4ln Fig.5On—lineITSPME-CGC—PFPDchromatogramsof aqueoussamplesspikedwithphosphoruscontaining pesticideschlorinatedpesticides Peakidentifications:lnIet11an1i(]aphos:!dichlor~os trichlorfon(dylox):3unknownpeak:4omel1toate;5dim ethoate;6propetamphos:7diazinon;8parathiol~methyl;9 chlorpyrifosmethyl+paraoxon:l()pirinuphoslnethyl+mala thion;l1parathionethyl:l!chlorpyrifos;l3isofent)hos+ quinalphos;14phoxim;J5ethion;16imidan:】7phosalone Thesameapparatuswason—linecoupledto CGCwithapulsedflamephotometricdetector (PFPDinPmode)todeterminethephosphorus containingpesticides.Sixteenstandardswere spikedto0.5g/Leachin30mLaqueoussample beforeextraction,andthedilutionofcompounds wasonceoperatedinsilexvialusingmicro—-syr-- inge(sucking30LLL2.5mg/Lstockto30mL purewater).ThechromatogramisshowninFig. 5,andthelowestdetectionof0.05g/Lcouldbe achievedformostoftheanalyteswithinasshort as5nljnextractjon. 3Conclusion TheITSPMEdevicepresentsthefollowing advantagesascomparedwithfiberSPME:(1) 50一foldhigherenrichmentfactoratoptimalcondi— tions;(2)fasterinextraction;(3)muchbetter repr0ducibility;(4)lessbleedingandsmoother baseline:(5)lowercost. References ArthurC.PawliszynJAnalChem.199062:2l45 LordH.PawliszynJJChromatogrA.2000.885:l53 LouehD.MotlaghS.PawliszynJAnalChem.1992,64: 1l87 BtlchholzKD.PawliszynJAnalChen1.1994.66:l60 Chen.1.PawliszynJAnalChem.1995.67:2520 EisertR.PawliszynJAnalChem.1997,69:3l40 MolHGJJanssenH—GCramersCA.JHighResolut Chromatogr.1993.16:4l3 WangHanwen,LiuWenminGuanYafengLC—GCNorth America.2004.22(1):16 BaltussenE,SandraP.DavidF,CramersCJMicroeol Sepl999,Il:737 Bi0graphicalSketch NameGUANYafengBirthdateJune7.1957NationalityChinese AffiliationDepartmentofAnalyticalChentistry&Micro— Instrumentation.DalianInstituteofChemicalPhysics,Chinese AcademyofSciencesl6lZhongshanRoad.DalianIl60l2,China Tel:+86—4ll-836935I5Fax:+86—4ll-83693479 E-mail:guan— yafeng@yahoo.corn.cnorkfguan@mail.dlptt.In.cn TitleProfessorandDirectorofDepartmentofAnalyticalChemistry&Micro— Instrumentation Dr.GUANYafengreceivedhisBAdegreeinl982fronttheChineseUniversityofScience&Technology,andDoctor DegreeofPhysicalChemistryinl986fromDalianInstituteofChemicalPhysics,ChineseAcademyofSciences.Professor LUPeichangandProfessorTANGXueyuanwerehisPh.Dsupervisors.HejoinedthegroupofProfessorF.BRUNERat theUniversityofUrbino,Italy.frontOct.1986toOctl987.andthenthegroupofProfessorC.A.CRAMERSattheTech— nicalUniversityofEindhoven,theNetherlands.fromNov.1987tillJan.1989,asapost— doctoralfellow.Inl989hejoined theDalianInstituteofChemicalPhysicsandcontinuedtheresearchworksthereuntilnow.Heiscurrentlyaprofessorof chemistry.DirectorofDepartmentofAnalyticalChemistry&Micro-Instrumentationofthisinstitute.Heisamemberof ScientificCommitteeoftheBasieResearchonChemistryofChineseAcademyofSciences,theViceChairmanoftheASSO- ciationofChineseAnalyticalInstruments,andtheStandingMemberoftheChineseChromatographySociety.Hehasmore thanl50publicationsand28patentsHewonasilverawardonNaturalSciencefromChineseAcademyofSciences.He wastheProminentYoungScientificFoundingwinnerandwasselectedastheHundredsofNationalTalentsintheNational SelectionProgramofHundreds/Thousands/Ten— thousandsTalents.Hisresearchinterestsinclude:miniaturizationofGC andHPLCinstrumentation.detectors.on— lineanalyzersforindustries.samplepretreatmentmethodologies,columns, capillaryLC—GC.andLC— MS.Applicationsincludeenvironmental,agriculture.food.petrochemicalandgasindustries. 23456789