Designation:D4590−18StandardTestMethodforColorimetricDeterminationofp-tert-ButylcatecholInStyreneMonomerorAMS(α–Methylstyrene)bySpectrophotometry1ThisstandardisissuedunderthefixeddesignationD4590;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodisapplicabletothedeterminationofresidual4-tertiary-butylcatechol(TBC)instyrenemonomerorAMSinthe1to100mg/kgrange.Anyothercompoundproducingcolorat490nmwhencontactedwithaqueoussodiumhydroxidesolutionwillinterfere.Itmaybecompen-satedforbyincludingitinthepreparationofthestandardsolutions,ifitsidentityandconcentrationinthesampleareknown.1.2Indeterminingtheconformanceofthetestresultsusingthismethodtoapplicablespecifications,resultsshallberoundedoffinaccordancewiththerounding-offmethodofPracticeE29.Thelimitofdetectionis0.2mg/kgwhilethelimitofquantitationis0.8mg/kgbasedontheILSdatainTable1.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.Forspecificstatementsonhazards,seeSection8.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterD3437PracticeforSamplingandHandlingLiquidCyclicProductsD4790TerminologyofAromaticHydrocarbonsandRelatedChemicalsD6809GuideforQualityControlandQualityAssuranceProcedure...
