ASTM_D_5713_-_14.pdf

Designation:D571314Standard Test Method forAnalysis of High Purity Benzene for Cyclohexane Feedstockby Capillary Gas Chromatography1This standard is issued under the fixed designation D5713;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 specificimpurities in,and the purity of benzene for cyclohexanefeedstock by gas chromatography.1.2 This test method has been found applicable to benzenein the range from 99 to 100%purity and to impurities atconcentrations of 2 to 10 000 mg/kg.1.3 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 E29.1.4 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 specific hazardstatements,see 7.2 and Section 8.2.Referenced Documents2.1 ASTM Standards:2D3437 Practice for Sampling and Handling Liquid CyclicProductsD4790 Terminology of Aromatic Hydrocarbons and RelatedChemicalsD6809 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 SpecificationsE260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relation-shipsE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other Document:OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.120033.Terminology3.1 Definitions:3.1.1 See Terminology D4790 for definition of terms used inthis test method.4.Summary of Test Method4.1 In this test method,the chromatogram peak area for eachimpurity is compared to the peak area of the internal standard(n-octane or other suitable known)added to the sample.Fromthe response factor of toluene relative to that of the internalstandard,and using a response factor of 1.00 for nonaromaticimpurities and the amount of internal standard added,theconcentrations of the impurities are calculated.The benzenecontent is obtained by subtracting the total amount of allimpurities from 100.00.5.Significance and Use5.1 This test method is useful for benzene purity on thebasis of impurities normally present in benzene and may beused for final product inspections and process control.5.2 This test method will detect the following impurities:toluene,methylcyclopentane,n-hexane,2-methylhexane,cyclohexane,cyclopentane,2-methylpentane,2,3-dimethylpentane,3-methylhexane,n-heptane,methylcyclohexane,ethylcyclopentane,2,4-dimethylhexane,trimethylpentane,and others where specific impurity standards1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.01 on Benzene,Toluene,Xylenes,Cyclohexane and TheirDerivatives.Current edition approved Feb.15,2014.Published March 2014.Originallyapproved in 1995.Last previous edition approved in 2009 as D5713 09.DOI:10.1520/D5713-14.2For 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 are available.Absolute purity cannot be accurately determinedif unknown impurities are present.6.Apparatus6.1 Gas ChromatographAny gas chromatograph having atemperature programmable oven,flame ionization detector anda splitter injector suitable for use with a fused silica capillarycolumn may be used,provided the system has sufficientsensitivity that will give a minimum peak height of 3 times thebackground noise for 2 mg/kg of an impurity.6.2 ColumnFused silica capillary columns have beenfound to be satisfactory.An example is 50 m of 0.20-mm insidediameter fused silica capillary internally coated to a filmthickness of 0.50 m with polydimethylsiloxane(see Table 1for suggested instrument parameters).Other columns may beused after it has been established that such a column is capableof separating all major impurities(for example,