ASTM_D_2710_-_20.pdf

Designation:D271020Designation:299/92(98)Standard Test Method forBromine Index of Petroleum Hydrocarbons by ElectrometricTitration1This standard is issued under the fixed designation D2710;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 petroleum hydrocarbons and isthus a measure of trace amounts of unsaturates in thesematerials.It is applicable to materials having bromine indexesbelow 1000.1.2 This test method is applicable only to essentially olefin-free hydrocarbons or mixtures that are substantially free frommaterial lighter than isobutane and have a distillation end pointunder 288 C(550 F).NOTE1This procedure has been cooperatively tested on materialswith bromine indexes in the range from 100 to 1000.These materialsinclude petroleum distillates such as straight-run and hydrocrackednaphtha,reformer feed,kerosine,and aviation turbine fuel.NOTE2Materials with bromine index greater than 1000 should betested for bromine number using Test Method D1159/IP 130.NOTE3Bromine index of industrial aromatic hydrocarbons should bedetermined using Test Method D1492 or D5776.The subcommittee iscurrently examining ways to achieve more consistent end point values.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses after SI units areprovided for information only and are not considered standard.1.4 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1159 Test Method for Bromine Numbers of PetroleumDistillates and Commercial Aliphatic Olefins by Electro-metric TitrationD1492 Test Method for Bromine Index of Aromatic Hydro-carbons by Coulometric TitrationD5776 Test Method for Bromine Index of Aromatic Hydro-carbons by Electrometric Titration3.Terminology3.1 Definitions:3.1.1 bromine index,nthe number of milligrams of bro-mine that will react with 100 g of sample under the conditionsof the test.4.Summary of Test Method4.1 A known mass of the sample dissolved in a specifiedsolvent is titrated with standard bromide-bromate solution.Theend point is indicated by a dead stop electrometric titrationapparatus when the presence of free bromine causes a suddenchange in the electrical conductivity of the system.5.Significance and Use5.1 This test method provides a measure of trace amounts ofunsaturated hydrocarbons in petroleum distillates boiling up to288 C(550 F).An estimate of the quantity of these materialsis useful in assessing the suitability of the lighter fractions foruse as reaction solvents.6.Apparatus6.1 Electrometric End Point Titration ApparatusAny ap-paratus designed to perform titrations to pre-set end points(seeNote 4)may be used in conjunction with a high-resistance1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricantsand is the direct responsibility ofSubcommittee D02.06 on Analysis of Liquid Fuels and Lubricants.Current edition approved May 1,2020.Published June 2020.Originallyapproved in 1968.Last previous edition approved in 2018 as D2710 09(2018).DOI:10.1520/D2710-20.In the IP,this test method is under the jurisdiction of the StandardizationCommittee.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.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.polarizing current supply capable of maintaining approxi-mately 0.8 V across two platinum electrodes and with asensitivity such that a voltage change of approximately 50 mVat these electrodes is sufficient to indicate the end poin