ASTM_D_5808_-_09a_2014.pdf

Designation:D580809a(Reapproved 2014)Standard Test Method forDetermining Chloride in Aromatic Hydrocarbons andRelated Chemicals by Microcoulometry1This standard is issued under the fixed designation D5808;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.Scope1.1 This test method covers the organic chlorides in aro-matic hydrocarbons,their derivatives,and related chemicals.1.2 This test method is applicable to samples with chlorideconcentrations from 1 to 25 mg/kg.1.3 This test method is preferred over Test Method D5194for products,such as styrene,that are polymerized by thesodium biphenyl reagent.1.4 In determining the conformance of the test results usingthis method to applicable specifications,results shall berounded off in accordance with the rounding-off method ofPractice E29.1.5 Organic chloride values of samples containing inorganicchlorides will be biased high due to partial recovery ofinorganic species during combustion.Interference from inor-ganic species can be reduced by water washing the samplebefore analysis.This does not apply to water soluble samples.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 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 specific hazardstatements,see 7.3 and Section 9.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1555M Test Method for Calculation of Volume and Weightof Industrial Aromatic Hydrocarbons and CyclohexaneMetricD3437 Practice for Sampling and Handling Liquid CyclicProductsD5194 Test Method for Trace Chloride in Liquid AromaticHydrocarbonsD6809 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 SpecificationsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Document:OSHA Regulations,29CFR paragraphs 1910.1000 and1910.120033.Terminology3.1 Definitions:3.1.1 dehydration tube,nchamber containing concen-trated sulfuric acid that scrubs the effluent gases from combus-tion to remove water vapor.3.1.2 oxidative pyrolysis,na process in which a sample iscombusted in an oxygen-rich atmosphere at high temperatureto break down the components of the sample into elementaloxides.3.1.3 recovery factor,nan indication of the efficiency ofthe measurement computed by dividing the measured value ofa standard by its theoretical value.3.1.4 reference sensor pair,ndetects changes in silver ionconcentration.3.1.5 test titration,na process that allows the coulometerto set the endpoint and gain values to be used for sampleanalysis.3.1.6 titration parameters,nvarious instrumental condi-tions that can be changed for different types of analysis.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved Feb.1,2014.Published February 2014.Originallyapproved in 1995.Last previous edition approved in 2009 as D5808 09a.DOI:10.1520/D5808-09AR14.2For 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.3Available 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 3.1.7 working electrode(generator electrode),nan elec-trode consisting of an anode and a cathode separated by a saltbridge;maintains a constant silver ion concentration.4.Summary of Test Method4.1 A liquid specimen is injected into a combustion tubemaintained at 900C having a flowing stream of oxygen andargon carrier gas.Oxidative pyrolysis converts the organichalides to hydrogen halides that then flow into a titration cellwhere it reacts with silver ions present in the electrolyte.Thesilver ion thus consumed is coulometrically replaced and thetotal electrical work to replace it is a measure of the organichalides in the specimen injected(see Annex A1).5.Significance and Use5.1 Organic as well as inorganic chlorine compounds canprove harmful to equipment and reactions in process