Designation:D2426−19StandardTestMethodforButadieneDimerandStyreneinButadieneConcentratesbyGasChromatography1ThisstandardisissuedunderthefixeddesignationD2426;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationofbutadienedimer(4-vinylcyclohexene-1)andstyreneinbutadieneconcentrates,bothrecycleandspecificationgrade.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.ForspecificprecautionarystatementsseeSections6and8.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1657TestMethodforDensityorRelativeDensityofLightHydrocarbonsbyPressureHydrometerD1945TestMethodforAnalysisofNaturalGasbyGasChromatographyD2593TestMethodforButadienePurityandHydrocarbonImpuritiesbyGasChromatography2.2OtherDocuments:2STP109APhysicalConstantsofHydrocarbonsC1toC103.SummaryofTestMethod3.1Thesampleisintroducedintoagas-liquidpartitioncolumn.Thecomponentsofinterestareseparatedastheyaretransportedthroughthecolumnbyacarriergas,andtheirpresenceintheeffluentisdetectedandrecordedasachromato-gram.Packedcolumnsareused,andeitherthermalconductiv-ityorionizationdetectorsarepermissible.Thequantityofthecomponentsofinterestpresentinthesampleisdeterminedfromthechromatogrambycomparingtheir...
