Designation:D8031−16StandardTestMethodforAcidNumberofTerephthalicAcid(TA)byAutomaticPotentiometricTitration1ThisstandardisissuedunderthefixeddesignationD8031;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofacidnumberinterephthalicacid(TA)byautomaticpotentiometrictitration.AstheindexofTApurity,acidnumberisusuallywithin674to676mgKOH/g.1.2Indeterminingtheconformanceofthetestresultsusingthismethod,resultsshallberoundedoffinaccordancewiththerounding-offmethodofPracticeE29.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D664TestMethodforAcidNumberofPetroleumProductsbyPotentiometricTitrationD1193SpecificationforReagentWaterD4790TerminologyofAromaticHydrocarbonsandRelatedChemicalsD6809GuideforQualityControlandQualityAssuranceProceduresforAromaticHydrocarbonsandRelatedMa-terialsE29PracticeforUsingSignificantDigitsinTestDatatoDetermineConformancewithSpecificationsE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE300PracticeforSamplingIndustrialChemicalsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod2.2OtherDocument:3OSHARegulations,29CFRparagraphs1910.1000and1910.12003.Terminology3.1Definitions:3.1.1acidnumber,n—thequantityofbase,expressedasmilligramsofpotassiumhydroxidepergramofsamplethatisrequiredtotitrateasampleinaspecifiedsolventtoaspecifiedendpoint.4.SummaryofTestMethod4.1ATAsampleisdissolvedinpyridine,dilutedwithwaterandtitratedpotenti...
