ASTM_D_1492_-_13.pdf

Designation:D149213Standard Test Method forBromine Index of Aromatic Hydrocarbons by CoulometricTitration1This standard is issued under the fixed designation D1492;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of the amountof bromine-reactive material in aromatic hydrocarbons.It isusually applied to materials having bromine indexes below500.NOTE1Other test methods for determining bromine-reactive materialare Test Methods D1159,D1491,D2710,and D5776.1.2 This test method has been found applicable to aromatichydrocarbons containing no more than trace amounts of olefinsand that are substantially free from material lighter thanisobutane and have a distillation end point under 288C.1.3 The following applies to all specified limits in this testmethod:For purposes of determining conformance with thistest method,an observed value or a calculated value shall berounded off“to the nearest unit”in the last right-hand digitused in expressing the specification limit,in accordance withthe rounding-off method of Practice E29.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For a specifichazard statement see Section 8.2.Referenced Documents2.1 ASTM Standards:2D891 Test Methods for Specific Gravity,Apparent,of LiquidIndustrial ChemicalsD1159 Test Method for Bromine Numbers of PetroleumDistillates and Commercial Aliphatic Olefins by Electro-metric TitrationD1193 Specification for Reagent WaterD1491 Test Method for Test for Bromine Index of AromaticHydrocarbons by Potentiometric Titration(Withdrawn1985)3D2710 Test Method for Bromine Index of Petroleum Hydro-carbons by Electrometric TitrationD3437 Practice for Sampling and Handling Liquid CyclicProductsD3505 Test Method for Density or Relative Density of PureLiquid ChemicalsD4052 Test Method for Density,Relative Density,and APIGravity of Liquids by Digital Density MeterD5776 Test Method for Bromine Index of Aromatic Hydro-carbons by Electrometric TitrationD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 Other Document:OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.120043.Terminology3.1 Definitions:3.1.1 bromine index(B),nthe number of milligrams(mg)of bromine consumed by 100 g of sample under givenconditions(mg-Br/100 g).4.Summary of Test Method4.1 The specimen is added to a solvent and titrated withelectrolytically generated bromine at room temperature.Theend point is determined by a dead-stop method.The time oftitration is proportional to the bromine added to the specimen.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved July 15,2013.Published September 2013.Originallyapproved in 1957.Last previous edition approved in 2008 as D1492 081.DOI:10.1520/D1492-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 This test method is useful for setting specification,foruse as an internal quality control tool,and for use in develop-ment or research work on industrial aromatic hydrocarbons andrelated materials.This test method gives a broad indication ofolefinic content.It will not differentiate between the types ofaliphatic unsaturation.6.Apparatus6.1 Amperometric-Coulometric Apparatus,automatic,suit-able for bromine index titrations with variable generatorcurrent and timer.A typical circuit diagram of suitable equip-ment is shown in Fig.1.6.2 Syringe,2 mL with needle and rubber cap seal.6.3 Stirrer,magnetic.7.Reagents7.1 Purity of ReagentReagent grade chemicals shall beused in all tests.Unless othe