Designation:D6591−19Designation:548/06StandardTestMethodforDeterminationofAromaticHydrocarbonTypesinMiddleDistillates—HighPerformanceLiquidChromatographyMethodwithRefractiveIndexDetection1ThisstandardisissuedunderthefixeddesignationD6591;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONThistestmethodhasthesametitleasIP548-06andisintendedtobetechnicallyequivalent.TheASTMformatfortestmethodshasbeenused,andwherepossible,equivalentASTMtestmethodshavereplacedtheIPorISOstandards.Thetestmethodisintendedtobeusedasoneofseveralpossiblealternativeinstrumentaltestmethodsthatareaimedatquantitativedeterminationofhydrocarbontypesinfuels.Thisdoesnotimplythatacorrelationnecessarilyexistsbetweenthisandanyothertestmethodintendedtogivethisinformation,anditistheresponsibilityoftheusertodeterminesuchcorrelationifnecessary.1.Scope*1.1Thistestmethodcoversahighperformanceliquidchromatographictestmethodforthedeterminationofmono-aromatic,di-aromatic,tri+-aromatic,andpolycyclicaromatichydrocarboncontentsindieselfuelsandpetroleumdistillatesboilingintherangefrom150°Cto400°C.Thetotalaromaticcontentin%m/miscalculatedfromthesumofthecorre-spondingindividualaromatichydrocarbontypes.NOTE1—Aviationfuelsandpetroleumdistillateswithaboilingpointrangefrom50°Cto300°CarenotdeterminedbythistestmethodandshouldbeanalyzedbyTestMethodD6379orothersuitableequivalenttestmethods.1.2Theprecisionofthistestmethodhasbeenestablishedfordieselfuelsandtheirblendingcomponents,containingfrom4%to40%(m/m)mono-aromatichydrocarbons,0%to20%(m/m)di-aromatichydrocarbons,0%to6%(m/m)tri+-aromatichydrocarbons,0%to26%(m/m)polycyclicaromatichydrocarbons,and4%to65%(m⁄m)totalaromatichydrocarbons.1.3Compoundscontainingsulfur,nitrogen,andoxygenarepossibleinterferents.Mono-alkenesdonotinterfere,butcon-jugateddi-andpo...
