Designation:D2425−21StandardTestMethodforHydrocarbonTypesinMiddleDistillatesbyMassSpectrometry1ThisstandardisissuedunderthefixeddesignationD2425;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversananalyticalschemeusingthemassspectrometertodeterminethehydrocarbontypespresentinconventionalandsynthesizedhydrocarbonsthathaveaboilingrangeof160°Cto343°C(320°Fto650°F),5%to95%byvolumeasdeterminedbyTestMethodD86.SampleswithaveragecarbonnumbervalueofparaffinsbetweenC12andC16andcontainingparaffinsfromC10andC18canbeanalyzed.Elevenhydrocarbontypesaredetermined.Theseinclude:paraffins,noncondensedcycloparaffins,condenseddicycloparaffins,condensedtricycloparaffins,alkylbenzenes,indansortetralins,orboth,CnH2n-10(indenes,etc.),naphthalenes,CnH2n-14(acenaphthenes,etc.),CnH2n-16(acenaphthylenes,etc.),andtricyclicaromatics.NOTE1—ThistestmethodwasdevelopedonConsolidatedElectrody-namicsCorporationType103MassSpectrometers.OperatingparametersforuserswithaQuadrupoleMassSpectrometerareprovided.1.2Thistestmethodisintendedforusewithfullboilingrangeproductsthatcontainnosignificantolefincontent.Biodiesel(FAMEcomponents)couldinterferewiththeseparationofthesampleandthecharacteristicmassfragmentsofFAMEcompoundsarenotdefinedintheprocedure.Hydrocarbonscontainingtertiarycarbonfragments,some-timesfoundinsyntheticaviationfuels,willinterferewiththecharacteristicmassfragmentsofparaffinsandresultinafalse,elevatedcycloparaffincontent.NOTE2—“Nosignificantolefincontent”forthismethodmeans<2.0%byvolumebyTestMethodD1319.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesafterSIunitsareprovidedforinformationonlyandarenotconsideredstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsi...
