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1、45.4.14C.ReagentsAOACOfficialMethod2001.10(a)Isoflavonestandards.—SeeTable2001.10J.DeterminationofIsoflavonesinSoy(b)Stockstandardsolutions.—UsinganalyticalbalancecapableandSelectedFoodsContainingSoyofweighingto0.00001g,weigh5mgdaidzin,5mggenistin,20mgExtraction,Saponifica
2、tion,andLiquidChromatographydaidzein,20mggenistein,and5mgglyciteininto5separate50mLFirstAction2001low-actinicvolumetricflasks.Quantitativelytransfercontentsof(Applicabletothedeterminationoftotalisoflavonecontentat2mgvialofglycitininto50mLlow-actinicvolumetricflask,rinsing$
3、50mg/g,individualisoflavoneglucosideandaglyconcontentatvialrepeatedlywithmethanolandaddingrinsingstovolumetricflask.Dissolvecontentsofeachflaskinmethanolanddilutetovol-$20mg,andisoflavonefamilysubtotalsat$20mg/ginsoyandfoodsume.Stoppereachflaskandmixwellbyrepeatedinversion
4、.Storeatcontainingsoy.)roomtemperatureinlow-actinicglassflasksfor#6months.SeeTables2001.10A–Ifortheresultsoftheinterlaboratorystudy(c)Workingstandardsolutions.—Prepare5levelsofworkingsupportingacceptanceofthemethod.standardsbydilutingthevolumeofeachstockstandardshowninA.Pr
5、incipleTable2001.10Kincorrespondingvolumetricflaskindicated.AddTestsamplesareextractedat65°Cfor2hinmethanol–water(80+volumeofwatershowninTable2001.10K,anddilutetovolume20),andtheextractsaresaponifiedatambienttemperaturewithwithmethanol–water(1+1).Theapproximateconcentratio
6、nofNaOHsolution.Theextractsareacidified,filtered,anddilutedwitheachisoflavoneisshowninTable2001.10L.Forstandardsofwatertomethanol–water(50+50).Theextractsarethencentrifuged<99+%purity,adjustvaluesforpurityofstandardaccordingly.toclarifythemandanalyzedbyliquidchromatography
7、(LC).Storesolutionsatroomtemperatureinlow-actinicglassflasksforIsoflavoneglucosidesandaglyconsareseparatedonaC18re-#6months.versed-phasecolumnwithamethanol–watermobilephaseanddeter-(d)Methanol.—LCgrade.minedbyUVdetectionat260nm.Resultsareexpressedinaglycon(e)Hexane.—LCgrad
8、e.unitsbysummingtheconcentrationsoftheaglyconisoflavones(f)Aceticacid,glacial.(genistein,
