离子液体在色谱中的应用

离子液体在色谱中的应用第一页，共十六页，编辑于2023年，星期一高效液相色谱法包括正相高效液相色谱法和反相高效液相色谱法。正相高效液相色谱法中流动相的极性小于固定相的极性，也就是以及性键合相为固定相（常以氨基、氰基键合相等作为固定相）。反相高效液相色谱法中流动相的极性大于固定相的极性，也就是以非极性键合相为固定相（常以十八硅烷C18、辛烷C8、甲基C1、苯基等作为固定相）。

离子对试剂是由强亲水离子形成，反作用于样品分子中的中性离心子对。因此，可用于同时分离带电分子和非带电分子。一般适用所有色谱固定相，流动相含水至少达10％，否则就有产生沉淀的危险（特别是在使用乙腈的情况下）。当使用长链的离子对试剂时，如十六烷基硫酸铵或十二烷基硫酸钠，色谱柱将选用反相色谱柱。2第二页，共十六页，编辑于2023年，星期一

抗衡离子：在离子型聚合反应中，存在于增长链末端活性离子附近的相反电性离子。

洗脱与洗脱剂：在洗脱色谱操作中，流动相携带待测组分在色谱柱内向钱移动并流出色谱柱的过程称为洗脱。所用流动相称为洗脱剂。3第三页，共十六页，编辑于2023年，星期一2.反相高效液相色谱法中离子液体作为流动相添加剂对儿茶酚胺保留值的影响3.离子交换色谱法和反相高效液相色谱法分析选定的离子液体阳离子4.1-烷基3-甲基咪唑离子液体作为洗脱剂对液相色谱法分离麻黄素的影响1.反相液相色谱法测定选择性室温离子液体阳离子5.离子液体双水相体系，高效液相色谱法测定鸦片生物碱的样品前处理过程4第四页，共十六页，编辑于2023年，星期一6.使用四氟硼酸咪唑离子液体抑制液相色谱分析中游离硅羟基的不利影响7.离子液体在液体色谱法中减少硅羟基的相互作用

8.基于离子液体的液相微萃取-高效液相色谱法测定水中有机磷农药9.液体作为高效液相色谱分析的添加剂：分析胺和离子液体的相互作用机制10.离子液体液液萃取-高效液相色谱测定水中酚类化合物5第五页，共十六页，编辑于2023年，星期一1.Reversed-phaseliquidchromatographicmethodforthedeterminationofselectedroom-temperatureionicliquidcations

Abstract

Theseparationofselected1-alkyl-and1-aryl-3-methylimidazolium-basedroomtemperatureionicliquidcationshasbeenperformedusingreversed-phasehigh-performanceliquidchromatographywithelectrosprayionizationmassdetection.TheRP-HPLCmethoddevelopmentstartedwiththeselectionofacolumntakingintoaccountespeciallytheresolutionoflowmolecularcongenersoftheselectedgroup.Mobilephasecompositionwasoptimizedforpeakresolution,sensitivityandhighreproducibilityofretentionvalues.Theresultsofthemethoddevelopmentwereappliedtothedeterminationofexemplaryionicliquidspeciespresentinthemediumusedincytotoxicitystudies.6第六页，共十六页，编辑于2023年，星期一2.EffectofIonicLiquidsasMobilePhaseAdditivesonRetentionofCatecholaminesinReversed-PhaseHigh-PerformanceLiquidChromatography

Abstract

Ionicliquidsorroomtemperatureionicliquidshavebeenwidelyinvestigatedasnewsolventsforcatalysisinthepastseveralyears.Becauseofsomespecialpropertiesofionicliquids,interestofusingthemindifferentchemicalprocessesisincreasing.Thisworkreportsontheuseof1-alkyl-3-methylimidazoliumsaltsandN-butyl-pyridiniumsaltsasnewmobilephaseadditivesforseparationofcatecholaminesinreversed-phasehigh-performanceliquidchromatography.Thegoodseparationisachievedbyusingtheseadditives.DifferentpHvaluesofthemobilephase,concentrationofionicliquids,anddifferentalkylsubstituentsonthecationsordifferentcounterionofionicliquidswereinvestigated.Theseparationmechanisminvolvesmolecularinteractionsbetweenionicliquidsandcatecholamines.

7第七页，共十六页，编辑于2023年，星期一3.Analysisofselectedionicliquidcationsbyionexchangechromatographyandreversed-phasehighperformanceliquidchromatography

Abstract

Thechromatographicbehaviorofionicliquids-homologuesof1-alkyl-3-methylimidazoliumand4-methyl-N-butylpyridinium-hasbeeninvestigatedwithastrongcationexchangeadsorbent.Inparticular,thedependenceoftheretentionpropertiesofthesesolutesonmobilephasecomposition,pH,andbufferconcentrationwasevaluatedwiththeaimofoptimizingandimprovingtheselectivityandretentionofsoluteseparation.WhileusingtheSCXstationaryphase,severalinteractionsoccurredwithvaryingstrengths,dependingonthemobilephasecomposition.Cationexchange,nonspecifichydrophobicinteractions,andadsorptionchromatographybehaviorwereobserved.Reversedphasechromatographyoccurredatlowconcentrationsofacetonitrile,electrostaticandadsorptioninteractionsathigherorganicmodifierconcentrations.Elevatedbufferconcentrationsloweredtheretentionfactorswithoutaffectingtheselectivityofionicliquids.Obtainedresultswerefurthercomparedtothechromatographicbehaviourofionicliquidsinthereversedphasesystem.Allanalyzedionicliquidsfollowreversed-phasebehaviorwhilebeingseparated.Muchlowerselectivityintherangeofhighlyhydrophiliccompoundsisobtained.Thissuggestspreferreduseofionchromatographyforseparationandanalysisofcompoundsbelow4carbonatomsinthealkylsidechain.

8第八页，共十六页，编辑于2023年，星期一4.Effectof1-alkyl-3-methylimidazolium-basedionicliquidsastheeluentontheseparationofephedrinesbyliquidchromatography

Abstract

Thechromatographicbehaviorofephedrines(norephedrine,ephedrine,pseudoephedrineandmethylephedrine)onaC18columnwasstudiedwithdifferentconcentrationsof1-butyl-3-methylimidazoliumtetrafluoroborateionicliquidsastheeluentatpH3.0.Theadditionofionicliquidhasgreateffectsontheseparationofthesebasiccompounds:decreasingbandtailing,reducingbandbroadening,andimprovingresolution.Theretentiontimesoftheanalytesincreaseatfirstandthendecreasewiththeincreaseintheconcentrationofionicliquid.Thiseffectmaybeattributedtothecompetitionbetweenimidazoliumcationsandthepolargroupsoftheanalytesforthesilanolgrouponthealkylsilicasurface,andalsototheformationofweakbilayerelectronicstructureontheC18column.Severalionicliquidswithdifferentalkylsubstituentsontheimidazoliumcationsorwithdifferentcounterionsastheeluentswerecompared.9第九页，共十六页，编辑于2023年，星期一5.Ionicliquid-basedaqueoustwo-phasesystem,asamplepretreatmentprocedurepriortohigh-performanceliquidchromatographyofopiumalkaloids

Abstract

Anionicliquid,1-butyl-3-methylimidazoliumchloride([C4mim]Cl)/saltaqueoustwo-phasesystems(ATPS)waspresentedasasimple,rapidandeffectivesamplepretreatmenttechniquecoupledwithhigh-performanceliquidchromatography(HPLC)foranalysisofthemajoropiumalkaloidsinPericarpiumpapaveris.Tofindoptimalconditions,thepartitionbehaviorsofcodeineandpapaverineinionicliquid/saltaqueoustwo-phasesystemswereinvestigated.Variousfactorswereconsideredsystematically,andtheresultsindicatedthatboththepHvalueandthesalting-outabilityofsalthadgreatinfluenceonphaseseparation.Therecoveriesofcodeineandpapaverinewere90.0–100.2%and99.3–102.0%,respectively,fromaqueoussamplesofP.papaverisbytheproposedmethod.10第十页，共十六页，编辑于2023年，星期一6.Suppressionofdeleteriouseffectsoffreesilanolsinliquidchromatographybyimidazoliumtetrafluoroborateionicliquids

Abstract

Silica-basedstationaryphasesarecommonlyusedinliquidchromatography,buttheirsurfaceaciditycausesknownproblems,especiallywhenseparatingbasiccompounds.Deleteriouseffectsoffreesilanolsarenotfullyremovedbystandardpreventionproceduresconsistinginaddingalkylaminesorotheraminoquencherstotheeluents.Wefoundthationicliquidsoftheimidazoliumtetrafluoroborateclass,addedtomobilephasesatconcentrationsof0.5–1.5%(v/v),blockedsilanolsandprovidedexcellentthin-layerchromatographicseparationsofstronglybasicdrugswhichwereotherwisenoteluted,evenwithneatacetonitrileasthemobilephase.Thesilanolsuppressingpotencyofimidazoliumtetrafluoroborateswasdemonstratedtomarkedlyexceedthatofthestandardmobilephaseadditives,liketriethylamine,dimethyloctylamineandammonia.Theproposednewmobilephaseadditiveswerealsodemonstratedtoprovidereliablelipophilicityparametersofbasedruganalytesasdeterminedbygradientmodeofhigh-performanceliquidchromatography.Byapplyingthereadilyavailableandenvironmentallyfriendlyimidazoliumtetrafluoroborateionicliquids,simpleandefficientmeansofimprovementofliquidchromatographicanalysisoforganicbaseswereelaborated.11第十一页，共十六页，编辑于2023年，星期一7.Reductionofsilanophilicinteractionsinliquidchromatographywiththeuseofionicliquids

Abstract

Asuppressionofsilanophilicinteractionsbytheselectedionicliquidsaddedtothemobilephaseinthin-layerchromatography(TLC)andhigh-performanceliquidchromatography(HPLC)isreported.Acetonitrilewasusedastheeluent,aloneorwithvariousconcentrationsofwaterandphosphoricbufferpH3.Selectivityofthenormal(NP)andthereversed(RP)stationaryphasematerialwasexaminedusingaseriesofproton-acceptorbasicdrugsanalytes.TheionicliquidsstudiedappearedtosignificantlyaffectanalyteretentioninNP-TLC,RP-TLCandRP-HPLCsystemstested.Consequently,theincreasedseparationselectivitywasattained.Duetoionicliquidadditivestoeluentevenanalytescouldbechromatographed,whichwerenotelutedfromthesilica-basedstationaryphasematerialswith100%ofacetonitrileinthemobilephase.Additionofionicliquidalreadyinverysmallconcentration(0.5%,v/v)couldreducetheamountofacetonitrileusedduringtheoptimizationofbasicanalytesseparationsinTLCandHPLCsystems.Moreover,theinfluenceoftemperatureontheseparationofbasicanalyteswasdemonstratedandconsideredinpracticalHPLCmethoddevelopment.12第十二页，共十六页，编辑于2023年，星期一8.DeterminationofOrganophosphorousPesticidesinWaterSamplesUsingIonicLiquid-basedLiquidPhaseMicroextractionCoupledwithHighPerformanceLiquidChromatographyXie

Abstract

Anovelmethodforthedeterminationofthreeorganophosphorouspesticides(phorate,parathionandpoxim)inwatersampleshasbeendevelopedusingionicliquid-basedliquid-phasemicroextractioncoupledwithhighperformanceliquidchromatography.Theinfluenceofextractionparametersincludingextractionsolvent,thevolumeratioofextractionsolventtosampleaqueous,extractiontime,extractiontemperatureandstirringratewasinvestigated.1-butyl-3-methylimidazoliumhexafluorophosphatewasusedasextractionsolventanddisplayedparticularadvantagescomparedwithvolatileorganicsolventssuchasbenzene,hexaneandacetone.Theproposedmethodprovidedenrichmentfoldsof665,630and553forphorate,parathionandpoxim,respectively.Themethodhadgoodlinearrangeof0.01-0.1μL/Landthelimitsofdetectionofthethreepesticideswereintherangeof0.001-0.01μL/L.TheRSDofmatrixspikedsampleswere3.4%,10.5%and2.4%forphorate,parathionandpoxim,respectively.13第十三页，共十六页，编辑于2023年，星期一9.Ionicliquidsasadditivesinhighperformanceliquidchromatography:Analysisofaminesandtheinteractionmechanismofionicliquids

Abstract

Asnovelsolvents,ionicliquidshavemanyapplicationsinsynthesis,catalysisandanalyticalseparation,i.e.extractionandchromatographyseparation.Inthispaper,someaminesincludingbenzidine,benzylamine,N-ethylanilineandN,N′-dimethylanilineareseparatedusingionicliquidsasadditivesforthemobilephaseinhighperformanceliquidchromatography(HPLC).Theeffectsofthelengthofalkylchainorcounterionsondifferentionicliquidsandtheirconcentrationsontheseparationoftheseanalytesareperformed.Thedifferencesbetweenionicliquidsandtetrabutylammoniumbromide(TBA)ontheseparationofo-,m-,p-phthalicacidsarecomparedandtheresultsshowthationicliquidsareion-pairreagentsinessence,althoughtheirhydrophobicityandhydrogenbondingalsoplayimportantroles.14第十四页，共十六页，编辑于2023年，星期一10.AnalysisofPhenolicCompoundsbyIonicLiquidBasedLiquidLiquidExtractionCoupledwithHighPerformanceLiquidChromatogra