Designation:D7621−16(Reapproved2021)IP570/15StandardTestMethodforDeterminationofHydrogenSulfideinFuelOilsbyRapidLiquidPhaseExtraction1,2ThisstandardisissuedunderthefixeddesignationD7621;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversprocedures(AandB)forthedeterminationofthehydrogensulfide(H2S)contentoffueloilssuchasmarineresidualfuelsandblendstocks,withviscosityupto3000mm2s-1at50°C,andmarinedistillatefuels,asmeasuredintheliquidphase.NOTE1—Specificationfuelsfallingwithinthescopeofthistestmethodare:ASTMSpecificationD396,MIL-DTL-16884,andISO8217.1.2ProcedureAhasbeenshowntoeliminateinterferencessuchasthiols(mercaptans)andalkylsulfides.ProcedureBcangiveelevatedresultsifsuchinterferencesarepresent(seeAnnexA2).NOTE2—AprocedureformeasuringtheamountofhydrogensulfideincrudeoilcanbefoundinAppendixX1.FullprecisionforAppendixX1hasnotyetbeendetermined.1.3ValidrangesfortheprecisionaregiveninTable2andTable3.Measurementscanbemadeoutsidetheserangeshoweverprecisionhasnotbeendetermined.1.4SamplescontainingFAMEdonotaffectthemeasure-mentofhydrogensulfidebythistestmethod.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Non-SIunitsgiveninparenthesesareforinformationonly.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.7Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:3D39...
