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1、4.1.09AImidazoleisusedasthebasetoneutralizetheacidsandbuffertheAOACOfficialMethod2001.12titrationsystem.(Note:ThepHofthesystemcouldbeupsetifafeed,DeterminationofWater/DryMatter(Moisture)suchasamineralmix,whichwaseitherastrongacidorbaseweretoinAnimalFeed,Grain,andForage(PlantTissue)beanalyzed.)KarlF
2、ischerTitrationMethodsOnesourceofinterferenceisfromaldehydesandketones,whichFirstAction2001reactwithmethanoltoformacetalsandketals,respectively,andwa-[Themethodisapplicabletothedeterminationof1–15%waterinter.Donotuseacetonetorinseglasswareorequipment.Theacetonedry,groundanimalfeedandforage.Itisnota
3、pplicableformineralresiduereactswithmethanoltoformacetonedimethylacetalandmixfeed.AnestimatedLODis0.25%andanestimatedLOQis0.8%water,andthusbiaswaterresultshigh.Additionalpotentialinterfer-for500mgtestportions(estimatedLODof0.12%andestimatedencesincludemetaloxides,suchasCaO,orothercompoundsthatLOQof
4、0.4%for1gtestportions).]canformwaterwhenneutralized;orthiols,suchascysteinehydro-chloride,orothercompoundsthatcanbeoxidizedbyiodine.Ifinter-®Caution:HYDRANAL-Composite5contains5hazardouscom-ferencesaresuspected,verifybyrunningthewaterstandardinponents—iodine,sulfurdioxide,imidazole,diethylenetripli
5、cateinthesamesolventasusedforthetestsampleimmediatelyglycolmonoethylether,andhydriodicacid,andshouldafterthetestsample,therebyretaininginterferingcompoundsinthebehandledwithcare.titrationflask.Inmostcases,ifinterferencesarepresent,theywillaf-fectthevalueforthewaterstandardinthesamemannerasthetestpo
6、r-SeeTables2001.12A–Cfortheresultsoftheinterlaboratorytion.Bealerttothepossibilityofpotentialinterferencesandrunwaterstudysupportingacceptanceofthemethods.standardsfrequently.Extractingreplicatesofatestsampleinthesamesolventmayalsomagnifyinterferenceeffects.Ifinterferingcom-A.Principlepoundsarefoun
7、d,additivesoralternativesolventsexisttodealwithForMethodI,waterisextractedfromtheanimalfeedorforagemany.materialintomethanol–formamide(1+1)directlyintheKarlFischertitrationvesselbyhigh-speedhomogenization.T
