RAPID DETERMINA TION OF L—GLUTAMIC ACID WITH AN ENZYME REACTOR OFL—GLUTAMIC DECARBOXYLASE IMMOBILIZED ON ION EXCHANGE RESIN

(整期优先)网络出版时间:2001-02-12
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ThepreparationandcharacterizationofanimmobilizedL-glutamicdecarboxylase(GDC)werestudiedThisworkistodevelopasensitivemethodforthedeterminationofL-glutamateusinganewbiosensor,whichconsistsofanenzymecolumnreactorofGDCimmobilizedonanovelionexchangeresin(carboxymethyl-copolymerofallyldextranandN.N'-methylene-bisacrylamideCM-CADB)andionanalyzercoupledwithaCO2electrode.Theconditionsfortheenzymeimmobilizationwereoptimizedbytheparameters:buffercompositionandconcentration,adsorptionequilibrationtime,amountofenzyme,temperature,ionicstrengthandpH.ThepropertiesoftheimmobilizedenzymeonCM-CADBwerestudiedbyinvestigatingtheinitialrateoftheenzymereaction,theefffectofvariousparametersontheimmobilizedGDCactivityanditsstability.AnimmobilizedGDCenzymecolumnreactormatchedwithaflowinjectionsystem-ionanalyzercoupledwithCO2electrode-datacollectionsystemmadeuptheoriginalformoftheapparatusofbiosensorfordeterminingofL-glutamateacid.Thelimitofdetectionis1.O×1O-5M.Thelinearityresponseisintherangeof5×1O-2-5×1O-5M.Theequationoflinearregressionofthecalibrationcurveisy=43.3x+181.6(yisthemilli-voltofelectricalpotentialresponse,xisthelogarithmoftheconcentrationofthesubstrateofL-glutamateacid).Thecorrelationcoefficientequals0.99.Thecoefficientofvariationequals2.7%.