外文翻译--毛细管电泳电化学检测方法 中文版.pdf

JOURNALOFCHROMATOGRAPHYA,834199989–101REVIEWELECTROCHEMICALDETECTIONMETHODSINCAPILLARYELECTROPHORESISANDAPPLICATIONSTOINORGANICSPECIESTHOMASKAPPES,PETERCHAUSERUNIVERSITYOFBASEL,DEPARTMENTOFCHEMISTRY,SPITALSTRASSE51,CH4056BASEL,SWITZERLANDABSTRACTTHETHREEELECTROCHEMICALDETECTIONMETHODSINCAPILLARYELECTROPHORESIS,NAMELYCONDUCTOMETRY,AMPEROMETRYANDPOTENTIOMETRY,AREDISCUSSEDANDCOMPAREDTOTHEMORECOMMONOPTICALDETECTIONMETHODSTHEPRINCIPLESOFEACHMETHODANDTHEIRIMPLEMENTATIONSAREDETAILEDANDREPORTEDAPPLICATIONSTOINORGANICSPECIESAREREVIEWED1999ELSEVIERSCIENCEBVALLRIGHTSRESERVEDKEYWORDSELECTROCHEMICALDETECTION；DETECTION,ELECTROPHORESIS；REVIEWS；INORGANICANIONS；METALCATIONSCONTENTS1INTRODUCTION892CONDUCTOMETRICDETECTION9021PRINCIPLE9022IMPLEMENTATIONS913AMPEROMETRICDETECTION9231PRINCIPLE9232IMPLEMENTATIONS934POTENTIOMETRICDETECTION9541PRINCIPLE9542IMPLEMENTATIONS955APPLICATIONSTOINORGANICSPECIES996CONCLUSIONS100REFERENCES1001INTRODUCTIONFORMOFCONDUCTOMETRY,AMPEROMETRYORPOTENTIOMETRYAREANATTRACTIVEALTERNATIVE,WHICH,HOWDETECTIONINCAPILLARYELECTROPHORESISCEISEVER,HASBEENEXPLOREDCOMPARATIVELYLITTLETHISISCOMMONLYCARRIEDOUTUSINGOPTICALMEANSABSORPININTERESTINGCONTRASTTOIONCHROMATOGRAPHY,THETIONANDFLUORESCENCEELECTROCHEMICALMEANSINTHEOTHERANDOLDERGENERALMETHODFORIONDETERMINATION,WHICHMAINLYEMPLOYSCONDUCTIVITYDETECTIONCORRESPONDINGAUTHORFAX141612671013ANDWHEREOPTICALMETHODSARESELDOMUSEDPERHAPS,00219673/99/–SEEFRONTMATTER1999ELSEVIERSCIENCEBVALLRIGHTSRESERVEDPIIS002196739800685290TKAPPES,PCHAUSER/JCHROMATOGRA834199989–101THISISEVENMORESURPRISINGWHENONECONSIDERSTHATTIONANDFLUORESCENCEMEASUREMENTSAREALSOREOPTICALDETECTIONISMADEMOREDIFFICULTINCAPILLARYSTRICTEDTOSPECIESTHATSHOWTHERESPECTIVEPROPELECTROPHORESISBECAUSEOFTHESMALLERCELLVOLUMESERTIESFORTHISREASON,INDIRECTOPTICALMETHODSAREANDTHEFACTTHATMANYIONSCANNOTBEDETECTEDOFTENUSEDINWHICHTHEDISPLACEMENTOFASENSEDDIRECTLYBYOPTICALMEANSTHEEXPLANATIONFORTHISAUXILIARYAGENTBYTHEANALYTESISMONITOREDFORCEDSITUATIONMAYBETWOFOLDFIRSTLY,ITISFAIRLYEASYTOBYTHEREQUIREMENTTOHAVEOVERALLCHARGENEUTRALITYADAPTABSORPTIONDETECTORS,ASWIDELYUSEDINHIGHTHISAPPROACHMAYALSOBEUSEDFORELECTROCHEMICALPERFORMANCELIQUIDCHROMATOGRAPHYHPLC,FORDETECTIONMETHODSWHENTHEANALYTESPECIESCANNOTCAPILLARIESMANYCEINSTRUMENTMANUFACTURERSAPBESENSEDDIRECTLYCHEMICALDERIVATIZATIONOFTHEPEARTOHAVEGONETHISROUTEANDHAVEINCORPORATEDANALYTEINORDERTOIMPARTDETECTABILITYISANOTHEREXISTINGDETECTORSINTOTHEIRCEEQUIPMENTSECONDLY,POSSIBLEAPPROACHNEITHEROFTHESEMEANSISIDEAL,THEAPPLIEDHIGHSEPARATIONVOLTAGEISANINTRINSICHOWEVER,ASINDIRECTDETECTIONONLYALLOWSANARROWINTERFERENCEINELECTROCHEMICALDETECTIONINTHEEARLYDYNAMICCONCENTRATIONRANGEANDDERIVATIZATIONADDSDAYS,ELABORATESCHEMESWEREEMPLOYEDTOOVERCOMETOTHECOMPLEXITYOFTHEMETHODINPRACTICE,THETHISDIFFICULTYINRECENTYEARS,ITHAS,HOWEVER,CHOICEOFTHEDETECTIONMETHODSHOULDPERHAPS,INTHEBECOMEEVIDENTTHAT,WITHTHECORRECTDESIGNOFTHEFIRSTINSTANCE,EXPLOITANINTRINSICPROPERTYFORDIRECTSYSTEM,THISDOESNOTHAVETOBEAPROBLEMSENSINGAND,SECONDLY,BEBASEDONTHEACHIEVABLECOMMONTOALLTHREEVARIANTSOFELECTROCHEMICALANDREQUIREDDETECTIONLIMITSACOMPROMISEMAYDETECTIONMEANSISTHEFACTTHATTHEYAREINTRINSICALLYHAVETOBEFOUNDWHENSEVERALSPECIESARETOBESIMPLERTHANTHEOPTICALMETHODSANELECTRICALSIGNALDETERMINEDASNOTALLMAYHAVETHESAMESETOFISOBTAINEDDIRECTLYWITHOUTTHEINVOLVEMENTOFANDETECTABLEPROPERTIESINTERMEDIATEPHYSICALPARAMETER,SUCHASRADIATIONOTHERREVIEWSONELECTROCHEMICALDETECTIONININTENSITYINOPTICALMETHODSTHEDETECTORHARDWARECAPILLARYELECTROPHORESISAREAVAILABLE1–5CONSISTSOFTHREEORFEWERSMALLELECTRODESANDSOMEFAIRLYSIMPLEELECTRONICCIRCUITRY,WHEREASFOROPTICALDETECTION,ALIGHTSOURCE,MONOCHROMATOR,OPTICAL2CONDUCTOMETRICDETECTIONDETECTORSANDFOCUSSINGOPTICSARENECESSARYINOPTICALMETHODS,THECELLVOLUMEDIRECTLYAFFECTSTHE21PRINCIPLESIGNALVIATHEOPTICALPATHLENGTHAND,FORTHISREASON,THECAPILLARYDIAMETERSALWAYSSHOULDBEASLARGEASHERETHEABILITYOFIONSTOCONDUCTCHARGEINPOSSIBLEFORELECTROCHEMICALDETECTION,THECELLSIZESOLUTIONISEXPLOITEDTHECURRENTPRODUCEDBETWEENSAMPLEVOLUMEHASONLYADIRECTBEARINGINCONTWOELECTRODESWHENAPPLYINGAVOLTAGEISMEASUREDDUCTIVITYMEASUREMENTSINAMPEROMETRY,THESIGNALAND,ACCORDINGTOOHM’SLAW,YIELDSTHERESISTANCEORISRELATEDTOTHEAREAOFTHEWORKINGELECTRODE,THETHECONDUCTANCEOFTHEELECTROLYTESOLUTIONINORDERSIZEOFWHICHWILLBELIMITEDBYTHEAVAILABLESAMPLETOSUPPRESSTHEINFLUENCEOFANYREDOXREACTIONTAKINGVOLUMEFORPOTENTIOMETRICDETECTION,THESIGNALISPLACEATTHEELECTRODES,CONDUCTOMETRICMEASURECOMPLETELYINDEPENDENTOFTHESENSORSIZEAND,MENTSAREUSUALLYCARRIEDOUTBYEMPLOYINGACTHEREFORE,OFTHECELLVOLUMEANDCAPILLARYDIAMETERVOLTAGESATAFREQUENCYOFTYPICALLY1KHZIFHIGHEROPTICALMETHODS,ONTHEOTHERHAND,HAVETHEADVANFREQUENCIESAREUSED,ITISPOSSIBLETOEMPLOYELECTAGEOFPROVIDINGCOMPLETEELECTRICALISOLATIONOFTHETRODESTHATARENOTINCONTACTWITHTHESOLUTION,BUTDETECTORFROMTHESEPARATIONVOLTAGEAPPLIEDTOTHEATTACHEDOUTSIDETHESAMPLECELL6THECONDUCTCAPILLARYANCEOFASOLUTIONLISDEPENDENTONTHEELECTRODECONDUCTIVITYDETECTIONCANBEREGARDEDASAAREAA,THEIRDISTANCEL,THECONCENTRATIONCOFUNIVERSALMETHOD,WHILEAMPEROMETRICDETECTIONISTHECHARGECARRIERSANDTHEIRMO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