1、Designation:D7266131Standard Test Method forAnalysis of Cyclohexane by Gas Chromatography(ExternalStandard)1This standard is issued under the fixed designation D7266;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last re
2、vision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTEThe number of samples in Section 15.1 was corrected editorially in April 2013.1.Scope*1.1 This test method covers the determination of t
3、he purityof cyclohexane by gas chromatography.Calibration of the gaschromatography system is done by the external standardcalibration technique.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 cycl
4、ohexane.Theimpurities can be analyzed over a range of 3 to 200 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 acc
5、ordance 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 theresponsibilit
6、y 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 Section 7.2.Referenced Documents2.1 ASTM Standards:2D3437 Practice for Sampling and Handling Liquid CyclicPro
7、ductsD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD4790 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
8、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 Chromat
9、ographs2.2 Other Document:OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.120033.Terminology3.1 See Terminology D4790 for definitions of terms used inthis test method.4.Summary of Test Method4.1 Cyclohexane is analyzed using a gas chromatograph(GC)equipped with a flame ionization detector(FID).
10、Aprecisely repeatable volume of the sample to be analyzed isinjected onto the gas chromatograph.The peak areas of theimpurities are measured and converted to concentrations via anexternal standard methodology.Purity by GC(the cyclohexanecontent)is calculated by subtracting the sum of the impuritiesf
11、rom 100.00.Individual impurities are reported in mg/kg.Thecyclohexane purity is reported in weight percent.5.Significance and Use5.1 This test method is suitable for setting specifications onthe materials referenced in Table 1 and for use as an internal1This test method is under the jurisdiction of
12、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.1,2013.Published March 2013.Originallyapproved in 2007.Last previous edition approved in 20
13、07 as D7266 071.DOI:10.1520/D7266-13E01.2For 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.Govern
14、ment 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 Stat
15、es1 quality 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 unusu
16、al impurities are present in the cyclohexane,this test method would not necessarily detect them and thepurity calculation would be erroneous.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.
