Designation:D7504−15´1StandardTestMethodforTraceImpuritiesinMonocyclicAromaticHydrocarbonsbyGasChromatographyandEffectiveCarbonNumber1ThisstandardisissuedunderthefixeddesignationD7504;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—ResearchReportinformationwasaddededitoriallyinSeptember2015.1.Scope*1.1Thistestmethodcoversthedeterminationoftotalnonaromatichydrocarbonsandmonocyclicaromatichydrocar-bonsinbenzene,toluene,ethylbenzene,p-xylene,o-xylene,styreneandmixedxylenesbygaschromatography.Thepurityofbenzene,toluene,ethylbenzene,p-xylene,o-xylene,styreneandmixedxylenesisalsocalculated.Similartestmethods,usingtheinternalstandardcalibrationtechniqueandtheexternalstandardcalibrationtechnique,areTestMethodsD2360,D3797,D4492,D5060,D5135,D5917,andD6563respectively.1.2Asmallamountofbenzeneintoluene,ethylbenzene,p-xylene,o-xylene,styreneandmixedxylenesmaynotbedistinguishedfromthenon-aromaticsandtheconcentrationsaredeterminedasacomposite(see6.1).1.3Thelimitofdetection(LOD)is0.0002wt%andlimitofquantitation(LOQ)is0.0006wt%forimpuritiesintoluene,mixedxylenes,p-xylene,o-xylene,ethylbenzene,benzene,andstyrene.1.4Indeterminingtheconformanceofthetestresultsusingthismethodtoapplicablespecifications,resultsshallberoundedoffinaccordancewiththerounding-offmethodofPracticeE29.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D841SpecificationforNitrationGradeTolueneD1555MTestMethodforCalculationofVolumeandWeightofIndustrialAromaticHydrocarb...
