Designation:D4768−11(Reapproved2019)StandardTestMethodforAnalysisof2,6-Ditertiary-ButylPara-Cresoland2,6-Ditertiary-ButylPhenolinInsulatingLiquidsbyGasChromatography1ThisstandardisissuedunderthefixeddesignationD4768;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationbygaschromatographyof2,6-ditertiary-butylpara-cresoland2,6-ditertiary-butylphenolinnewandusedinsulatingliquidsatconcentrationsupto0.5%.ItincludesthedeterminationinTypeIandIIinsulatingmineraloilsasspecifiedinSpecifica-tionD3487,buthasalsobeenusedtomeasuretheseinhibitorsinotherinsulatingliquids,suchasestersandhighfire-pointhydrocarbons.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.3Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D923PracticesforSamplingElectricalInsulatingLiquidsD3487SpecificationforMineralInsulatingOilUsedinElectricalApparatusD5222SpecificationforHighFire-PointMineralElectricalInsulatingOilsE260PracticeforPackedColumnGasChromatography3.SummaryofTestMethod3.1Thetestspecimenisplacedontoacolumncontainingactivatedaluminaandextractedtoremoveinterferingsub-stances.Theinhibitorsarethenelutedfromthecolumnwithsuitablesolventandanalyzedbygaschromatography.Theinhibitortypeandquantityaredeterminedbycomparisonofeachcomponentwithaworkingstandardtestedundersimilarconditions.4...
