【英文标准名称】:StandardTestMethodsforFattyandRosinAcidsinTallOilFractionationProductsbyCapillaryGasChromatography
【原文标准名称】:用毛细管气相色谱法对妥尔油分级分离产品的脂肪和树脂酸的标准试验方法
【标准号】:ASTMD5974-2000(2010)
【标准状态】:现行
【国别】:美国
【发布日期】:2000
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D01.34
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:areapercent;derivatization;fattyacids;gaschromatography;internalstandard;rosinacids;Capillarygaschromatography;Areapercent;Derivatization;Fattyacids--tests;Fractionationproducts;Gaschromatography(GC)--paints/relatedcoatings/materia
【摘要】:Talloilfractionatedproductsderivedfromtalloilareimportantcommercialmaterials,primarilycomposedoffattyacidsandrosinacids,butalsocontainingsomeneutralmaterial(seeTerminologyD804).Formanyapplications,itisnecessarytoknowtheleveloftheindividualfattyacidsandrosinacidspresentintheseproducts.Gaschromatographyhasproventobeausefultoolforsuchdeterminations(seeTestMethodsD509),andcapillarychromatography,describedinthesetestmethods,isconsideredtobethemosteffectivegaschromatographictechniquecurrentlyavailable.Inparticularsituations,othertechniquesmaybemoresuitablethangaschromatography.Forexample,thepresenceoffattyacidestersinthesamplewouldresultintransesterificationduringthederivatizationstepthatmayaffecttheresults.Duetohydrogenbonding,unmodifiedtalloilfattyacidsandrosinacidscannotbevolatilizedatatmosphericpressurewithoutundergoingdecomposition.So,itisnecessarytoconvertthefreeacidstothemorevolatileandmorestablemethylesters,priortochromatographicseparation.Thesetestmethodsdescribefourwaystopreparemethylesters.Theclassicmethodisthroughtheuseofdiazomethane,butdiazomethaneisahazardousandtoxicmaterial,andsoisnolongerthepreferredagent.TheuseofdiazomethaneisdetailedintheAppendix.TMAHcausesisomerizationofasample''sdi-andpolyunsaturatedfattyacids,whenitisusedinevenaslightexcess.Thisleadstoinaccurateresultsfortheindividualfattyacidcomponents.TMAHshouldbeusedformaterialscontainingonlyrosinacids,orwhentheidentificationorquantitationofindividualfattyacidcomponentsisnotimportant.TMPAHistherecommendedmethylatingagentwhentheidentificationorquantitationofindividualdi-andpolyunsaturatedfattyacidsisrequired.TMPAHproducesresultsthatareverysimilartothoseofdiazomethane,butwithoutthehazardsthatareassociatedwithdiazomethane.AconsiderableexcessofTMPAHmaycauseisomerizationofconjugatedcompoundssimilartothatencounteredwithTMAH.DMF-DMAgivesresultscomparabletoTMPAHandiseasyandsafetouse.However,thereagentismoisturesensitive,requiringsamplestobefreeofanysignificantlevelsofwater.Twotestmethodsforcalculatingtheamountsoftheindividualfattyacidandrosinacidmethylestersareincludedinthesetestmethods.Whentheactualweightpercentageofagivencompoundisrequired,thex201C;internalstandardx201D;methodmustbeused.Thismethodinvolvesaddingaknownamountofaninternalstandardtoaknownamountoftestmaterial,andcomparingtheareaofthepeakassociatedwiththeinternalstandardwiththeareaofthepeakoftheindividualfattyacidorrosinacidmethylesters.Thex201C;areapercentx201D;methodwillgivetherelativeamountofeachcomponent,bycomparingtheareaoftheappropriatepeaktothetotalareaofallpeaks.Non-elutingcompoundswillleadtoerroneous(absolute)resultswiththismethod.PREPARATIONOFMETHYLESTERSTopNote18212;Anyofthesethreemethodscanbeused,withthechoicebeingdependentonthefactorsmentionedin3.3.1.1Thesetestmethodscoverthedeterminationoftheamountsoftheindividualfattyacidsandrosinacidsinfractionatedtalloilproducts,usingcapillarygaschromatographicseparationofth......
【中国标准分类号】:G16
【国际标准分类号】:67_200_10
【页数】:6P.;A4
【正文语种】:英语