胶束毛细管电泳分析杀虫剂

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1、JournalofChromatographyA,1153(2007)104–113On-linepreconcentrationstrategiesforanalyzingpesticidesinfruits andvegetablesbymicellarelectrokineticchromatographyAnaJuan-Garc´ıa,GuillerminaFont,YolandaPico´∗LaboratorideBromatologiaiToxicologia,FacultatdeFarma`cia,UniversitatdeVal

2、e`ncia,Av.VicentAndre´sEstelle´ss/n, 46100Burjassot,Vale`ncia,SpainAvailableonline4February2007AbstractFivepesticides(fludioxonil,procymidone,pyriproxyfen,dinosebandcarbendazim)wereseparatedinreversedmigrationmicellarelectrokinetic chromatography(RM-MEKC)using20mmoll−1phospha

3、tebufferatpH2.3,containing25mmoll−1sodiumdodecylsulfateand10%methanol. Threeon-lineconcentrationstrategies,sweeping(SW),normalstackingwithreversedmigrationandawaterplug(SRW)andstackingwithreverse migrationandremovalofsamplematrixusingpolarityswitching(SRMM),werecompared.Abou

4、t10-,30-and50-foldincreasesindetection sensitivity,comparedwithstandardhydrodynamicinjection(5sat0.5psi),wereobservedwithSW,SRWandSRMM,respectively.Limitsof detection(LODs)rangedfrom0.002to0.03␮gml−1usingonlytheon-linepreconcentrationprocedureswithoutanyoff-lineconcentration

5、of theextract.Asolid-phaseextraction(SPE)procedure,forpreviousisolationandconcentrationoftheanalytes,wasusedincombinationwithany oftheproposedon-linepreconcentrationstrategies,whichachievesthedeterminationofpesticidesatlimitsofquantification(LOQs)lowerthan 0.01mgkg−1.Therecov

6、eriesobtainedbySPEinsamplesspikedat0.01mgkg−1werebetween70and100%,withRSDsbetween10and18% usingSRMM.Samplesoffruitsandvegetablesweretakenfromthemarket,extractedbytheproposedprocedureandanalyzedwithRM-MEKC withtheon-linestrategies.©2007ElsevierB.V.Allrightsreserved.Keywords:F

7、oodanalysis;SW;SRW;SRMM;Reversedmigrationmicellarelectrokineticchromatography;Pesticides;Solid-phaseextraction1.IntroductionOvertheyears,researchinthefieldofpesticideresiduesanalysisinfoodhasexperiencedacontinuousexpansionofthenumberoftechniquesavailablefordeterminingtheircon

8、tentindifferentfruitsandvegetables[1,2].Thestate-of-the-arthasprogressedtot