1、Designation:D 3798 03Standard Test Method forAnalysis ofp-Xylene by Gas Chromatography1This standard is issued under the fixed designation D 3798;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 p
2、arentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of knownhydrocarbon impurities in,and the purity of p-xylene by gaschromatography(GC).It is generally mean
3、t for the analysis ofp-xylene of 99%or greater purity.Impurity concentrations thatcan be measured range from 0.001 to 1.000 weight%.1.2 The following applies to all specified limits in this testmethod:for purposes of determining conformance with thistest method,an observed value or a calculated valu
4、e shall berounded off 8to the nearest unit in the right-hand digit used inexpressing the specification limit,in accordance with therounding-off method of Practice E 29.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of th
5、e user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For a specifichazard statement,see Section 9.2.Referenced Documents2.1 ASTM Standards:D 3437 Practice for Sampling and Handling Liquid CyclicProducts2
6、D 4790 Terminology of Aromatic Hydrocarbons and Re-lated Chemicals2D 5136 Specification for High Purity p-Xylene2E 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3E 260 Practice for Packed Column Gas Chromatography3E 355 Practice for Gas Chromatograp
7、hy Terms and Rela-tionships3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3E 1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs42.2Other Document:OSHA Regulations,29 CFR,paragraphs 1910.1000 and1910.120053.
8、Terminology3.1 Definitions:3.1.1 For definition of terms used in this test method seeTerminology D 4790.4.Summary of Test Method4.1 A known amount of an internal standard is added to aspecimen of p-xylene.The prepared specimen is mixed andanalyzed by a gas chromatograph equipped with a flameionizati
9、on detector(FID).The peak area of each impurity andthe internal standard is measured.The amount of each impurityis calculated from the ratio of the peak area of the internalstandard versus the peak area of the impurity.Purity by GC(the p-xylene content)is calculated by subtracting the sum ofthe impu
10、rities found from 100.00.Results are reported inweight percent.5.Significance and Use5.1 This test method is suitable for setting specifications onp-xylene and for use as an internal quality control tool wherep-xylene is produced or is used in a manufacturing process.Itmay also be used in developmen
11、t or research work involvingp-xylene.It is generally applied to determining those com-monly occurring impurities such as nonaromatic hydrocarbons,benzene,toluene,ethylbenzene,m-xylene,o-xylene,andcumene(isopropylbenzene).5.2 Purity is commonly reported by subtracting the deter-mined expected impurit
12、ies from 100.00.However,a gaschromatographic analysis cannot determine absolute purity ifunknown components are contained within the material beingexamined.Refer to Specification D 5136 for determining otherchemical and physical properties of p-xylene.1This test method is under the jurisdiction of A
13、STM 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 10,2003.Published July 2003.Originallyapproved in 1979.Last previous edition approved in 20
14、00 as D 3798 00.2Annual Book of ASTM Standards,Vol 06.04.3Annual Book of ASTM Standards,Vol 14.02.4Annual Book of ASTM Standards,Vol 03.06.5Available from Superintendent of Documents,U.S.Government PrintingOffice,Washington,DC 20402.1*A Summary of Changes section appears at the end of this standard.
15、Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.Interferences6.1 The internal standard chosen must be sufficiently re-solved from any impurity and the p-xylene peak.Refer to 8.4.1.7.Apparatus7.1 Gas ChromatographAny chromatograph having
16、aflame ionization detector that can be operated at the conditionsgiven in Table 1.The system should have sufficient sensitivityto obtain a minimum peak height response for a 0.001 weight%impurity twice the height of the signal background noise.7.2 ColumnsDifferent columns have been found satisfac-tory,depending on the purity of the p-xylene to be analyzed.7.2.1p-Xylene Range from 99.0 to 99.8%Both capillaryand packed columns have been found satisfactory.The columnmust give satisfactory separatio
