ASTM_D_7871_-_13.pdf

Designation:D787113Standard Test Method forAnalysis of Cyclohexane by Gas Chromatography(EffectiveCarbon Number)1This standard is issued under the fixed designation D7871;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 determination of the purityof cyclohexane by gas chromatography.1.2 This test method has been found applicable to themeasurement of impurities such as those found in Table 1,which are impurities that may be found in cyclohexane.Theimpurities can be analyzed over a range of 1 to 400 mg/kg bythis method,but may be applicable to a wider range.1.3 The limit of detection is 1 mg/kg.1.4 In determining the conformance of the test results usingthis test method to applicable specifications,results shall berounded off in accordance with the rounding-off method ofPractice E29.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 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 hazardsstatements,see 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 SpecificationsE355 Practice for Gas Chromatography Terms and Relation-shipsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other Standards:3OSHA Regualtions,29 CFR paragraphs 1910.1000 and1910.12003.Terminology3.1 See Terminology D4790 for definitions of terms used inthis test method.4.Summary of Test Method4.1 The specimen to be analyzed is injected into a gaschromatograph equipped with a flame ionization detector(FID)and a capillary column.The peak area of each component ismeasured and adjusted using effective carbon number(ECN)4response factors.The concentration of each component iscalculated based on its relative percentages of total adjustedpeak area and normalized to 100.0000%.5.Significance and Use5.1 This test method is suitable for setting specifications onthe materials referenced in Table 1 and for use as an internalquality control tool where cyclohexane is produced or is usedin a manufacturing process.It may also be used in developmentor research work involving cyclohexane.5.2 This test method is useful in determining the purity ofcyclohexane with normal impurities present.If extremely highboiling or unusual impurities are present in the cyclohexane,this test method would not necessarily detect them and thepurity calculation would be erroneous.1This 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 June 1,2013.Published July 2013.DOI:10.1520/D7871-13.2For 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.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.4Scanlon,J.T.and Willis,D.E.,“Calculation of Flame Ionization DetectorRelative Response Factors Using the Effective Carbon Concept,”Journal ofChromatographic Science,Vol.23,August 1985,ppl.333-339.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Apparatus6.1 Gas ChromatographAny instrument having a flameionization detector that can be operated at the conditions givenin Table 2.The system should have sufficient sensitivity toobtain a minimum peak height response for 1 mg/kg benzeneof twice the height of the signal background noise.6.2 ColumnsThe choice of column is based on resolutionrequirements.Any column may be used that is capable ofresolving all significant impurities from cyclohexane.Thecolumn described in Table 2 has been used successfully.6.3 RecorderElectronic integration is required.6.4 InjectorThe specimen must be precisely and repeat-ably injected into the gas chromatograph.An automatic sampleinjection device