1、Designation: D 6563 05Standard Test Method forBenzene, Toluene, Xylene (BTX) Concentrates Analysis byGas Chromatography1This standard is issued under the fixed designation D 6563; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses 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 the totalnonaromatic hydrocarbons, benzene, toluene, ethylbenz
3、ene,xylenes, and total C9+ aromatic hydrocarbons in BTX con-centrates by capillary column gas chromatography. This testmethod is applicable to materials with a final boiling pointbelow 215C.1.2 This test method may also be used to determine therelative distribution of the individual C8aromatic hydro
4、carbonisomers in mixed xylenes.1.3 Individual components can be determined from 0.01 to90 %.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 The values state
5、d 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
6、health practices and determine the applica-bility of regulatory limitations prior to use. For a specificprecautionary statement, see Section 9.2. Referenced Documents2.1 ASTM Standards:2D 3437 Practice for sampling and Handling Liquid CyclicProductsD 6809 Guide for Quality Control and Quality Assura
7、nceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 355 Practice for Gas Chromatography Terms and Rela-tionshipsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precisi
8、on of a Test MethodE 1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other Documents:OSHA Regulations, 29 CFR, paragraphs 1910.1000 and1910.120033. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 extracted reformate, nAn aromatic c
9、oncentrate ob-tained by solvent extraction of reformate.3.1.2 reformate, nThe product of a catalytic process thatincreases the concentration of aromatic hydrocarbons.3.1.3 pyrolysis gasoline, nDepentanized by-product re-covered from ethylene manufacture.3.1.4 synthetic blend, nBlend of reagent hydro
10、carbonsthat simulate a process product.3.1.5 hydrogenated pyrolysis gasoline, nPyrolysis gaso-line that has been treated with hydrogen to reduce the olefinscontent.3.1.6 crude ethylbenzene, nProduct produced from thereaction of impure fluid cat cracking, (FCC) ethylene andbenzene.3.1.6.1 DiscussionI
11、t typically contains greater than 40 %of ethylbenzene and benzene.3.1.7 light blending aromatics feedstock, nLight aromat-ics fraction (with high amounts of benzene and toluene)typically recovered from the isomerization of a p-xylene orm-xylene depleted C8aromatics stream.3.1.8 mixed xylenes, na mix
12、ture of C8aromatic hydrocar-bon isomers including ethylbenzene, but excluding stryene.4. Summary of Test Method4.1 The specimen to be analyzed is injected into a gaschromatograph equipped with a flame ionization detector (FID)1This test method is under the jurisdiction of ASTM Committee D16 onAromat
13、ic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.01 on Benzene, Toluene, Xylenes, Cyclohexane, and TheirDerivatives.Current edition approved July 1, 2005. Published August 2005. Originallyapproved in 2000. Last previous edition approved in 2000 as D 6463 00.2
14、For 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 the Superintendent of Documents, U.S. Governme
15、nt PrintingOffice, Washington, DC 20402.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.and a capillary column. The peak area of each component ismeasured and adjusted
16、 using effective carbon number (ECN)response factors. The concentration of each component iscalculated based on its relative percentages of total adjustedpeak area and normalized to 100.00. To determine the relativedistribution of C8aromatic hydrocarbons, the peak areas ofthose components only are n
17、ormalized to 100.00.4.2 Results can be reported as either volume or weightpercent. Volumetric results can be derived by dividing eachcomponents weight percent by its relative density and re-normalizing to 100 %.5. Significance and Use5.1 This test method was primarily developed to determinebenzene,
18、toluene, and xylenes in chemical intermediate andsolvent streams such as reformate, BTX extracts, pyrolysisgasoline, hydrogenated pyrolysis gasoline, crude benzene,crude ethylbenzene, commercial toluene, and light blendingaromatic feedstocks. This test method may not detect allcomponents and there m
19、ay be unknown components thatwould be assigned inappropriate response factors and thus, theresults may not be absolute.5.2 The relative distribution of C8aromatics is useful fordetermining conformance to p-xylene feedstock specifications.6. Interferences6.1 Nonaromatic hydrocarbons may interfere wit
20、h the de-termination of benzene and toluene when certain columns areused.6.2 Styrene may be present in some samples. It will elutewith C9+ aromatics.7. Apparatus7.1 Gas ChromatographAny gas chromatograph having aflame ionization detector and a splitter injector suitable for usewith a fused silica ca
21、pillary column may be used, provided thesystem has sufficient sensitivity, linearity, and range to obtain aminimum peak height response for a 0.01 % peak of five timesthe height of the signal background noise, while not exceedingthe full scale of either the detector or the electronic integrationfor
22、the highest peak. The split injection system shall notdiscriminate over the boiling range of the samples analyzed.The system shall be capable of operating at the conditionsgiven in Table 1.7.2 ColumnsThe choice of column is based upon resolu-tion requirements. Any column may be used that is capable
23、ofresolving all the components of interest. The column andconditions described in Table 1 have been used successfullyand will be the referee in case of dispute.7.3 Recorder/Electronic IntegrationElectronic integrationwith tangent capabilities is recommended.8. Reagents8.1 Carrier GasHelium with a mi
24、nimum purity of 99.99mol %.8.2 Detector GasHydrogen with a minimum purity of99.99 mol %.8.3 Flame Support GasAir, total, hydrocarbon less than 5ppm.9. Hazards9.1 Consult current OSHA regulations, suppliers MaterialSafety Data Sheets, and local regulations for all material usedin this test method.10.
25、 Sampling10.1 Sample material in accordance with Practice D 3437.11. Preparation of Apparatus11.1 ChromatographFollow manufacturers instructionsfor mounting and conditioning the column in the chromato-graph. Adjust the instrument to the conditions as described inTable 1 to give the desired separatio
26、n using the suggestedcolumn. Other columns may require different conditions toachieve the resolution requirements. Allow sufficient time forthe instrument to reach equilibrium as indicated by a stablerecorder/electronic baseline. See Practices E 355 and E 1510for additional information on gas chroma
27、tography practicesand terminology.12. Procedure12.1 Bring the sample to ambient room temperature.12.2 Inject an appropriate amount of sample into the chro-matograph that meets the criteria outlined in 7.1. See PracticesE 355 and E 1510 for additional information on gas chroma-tography practices and
28、terminology.12.3 Sample chromatograms are illustrated in Figs. 1-4.12.4 Measure the area of all peaks. The non-aromaticsfraction includes all peaks up to ethylbenzene (except for thepeaks assigned to benzene and toluene). Sum together all thenon-aromatic peaks as a total area. The C9+ aromatics frac
29、tionincludes all peaks eluting after m-xylene except for 0-xylene.Sum together all the C9+ aromatic peaks as a total area.13. Calculation13.1 Calculate the weight percent concentration of eachcomponent as follows:Ci5100 3 Ai3 ECNi(i 5 1nAi3 ECNi!(1)TABLE 1 Instrument ParametersColumn 50 or60 m by 0.
30、25 mm ID bondedpolyethylene glycol-fused silica capillary,internally coated to a 0.25-m thicknessCarrier gas heliumFlow, linear velocity at 70C, cm/s 20Split ratio 200:1Detector gasHydrogen flow rate, mL/min 30Air flow rate, mL/min 300Make-up flow rate, mL/min 30Sample size, L 0.5TemperaturesInjecto
31、r, C 250Detector, C 300ColumnInitial, C 70Hold, min 10Rate, C/min 5Final, C 200Hold, min 24D6563052FIG. 1 Synthetic BlendD6563053FIG. 2 Pyrolysis GasolineD6563054FIG. 3 Extracted ReformateD6563055FIG. 4 Mixed XylenesD6563056where:Ci= concentration of component inweight percent,Ai= area of component,
32、 i peak,ECNi= effective carbon response factorfor component, and(i 5 1nAi3 ECNi! = the summation of all response cor-rected areas in the chromatogram.13.2 Calculate the volume percent concentration of eachcomponent as follows:V 5100 C/D(i 5 1nC/D!(2)where:V = calculated vol % concentration of compon
33、ent,C = calculated wt % concentration of component from12.1,D = relative density of component, andi=1n= sum of the quotients C/D.13.3 Use the following effective carbon number (ECN)response factors for the calculations:ComponentECN ResponseFactorA,BRelative DensityCat 60FNon Aromatics 1.0000 0.7200
34、(average)Benzene 0.9100 0.8829Toluene 0.9200 0.8743Ethylbenzene 0.9275 0.8744p-Xylene 0.9275 0.8666m-Xylene 0.9275 0.8694o-Xylene 0.9275 0.8849_ C9+ aromatics 0.9333 0.8752 (average)AScanlon, J., T., and Willis, D., E., “Calculation of Flame Ionization DectorRelative Response Factors Using the Effec
35、tive Carbon Number Concept” Journalof Chromatographic Science, Vol 35, August, 1985, pp. 333-339.BResponse Factors are relative to n-heptane.CDS#4APhysical Constants of Hydrocarbons C1through C10, ASTM, 1971.13.4 Calculate the weight percent relative distribution ofeach C8aromatic hydrocarbon as fol
36、lows:F15100 3 B1(i 5 1nB1(3)where:F1= concentration of component in weight percent,B1= peak area of component i, and= peak area o fall C8aromatic isomers.14. Report14.1 Report the following information:14.1.1 All component concentrations to the nearest 0.01 wt(or vol) %.14.1.2 For concentrations les
37、s than 0.01 wt (or vol) %,report as 0.01 wt (or vol) %.15. Precision and Bias415.1 PrecisionThe following criteria should be used tojudge the acceptability of results obtained by this test method(95 % confidence level). The precision criteria were derivedfrom an interlaboratory study using data subm
38、itted by fourteenlaboratories (ten laboratories for mixed xylenes. Each inter-laboratory study participant was provided two gravimetricallyprepared BTX known samples and three unknown samples ofvarying concentrations. Each sample was run twice on twodays by two different operators. Results of the in
39、terlaboratorystudy were calculated and analyzed using Practice E 691.15.2 Intermediate Precision, (formerly Repeatability)Results in the same laboratory should not be consideredsuspect unless they differ by more than 6 the amount shown inTable 2, Table 3, Table 4, Table 5, Table 6,orTable 7.Onthebas
40、is of test error alone, the difference between two resultsobtained in the same laboratory on the same material will beexpected to exceed this value only 5 % of the time.15.3 ReproducibilityResults submitted by each of twolaboratories should not be considered suspect unless they differby more than 6
41、the amount shown in Table 2, Table 3, Table4, Table 5,orTable 6. On the basis of test error alone, thedifference between two results obtained in different laborato-ries on the same material will be expected to exceed this valueonly 5 % of the time.15.4 BiasFor mixed xylenes, the interlaboratory test
42、 uti-lized a sample prepared gravimetrically from individual fromindividual C8isomers obtained at the highest purity available.However, this sample has not been approved as an acceptablereference material and consequently bias has not been deter-mined.15.4.1 As an aid for the users in determining th
43、e possibilityof bias, calculated C8distributed for the round robin sample islisted in Table 7 as the “Expected Concentration.” The averagevalue for each C8isomer as calculated from the reportedconcentrations is listed as “Average Concentration Reported.”16. Quality Guidelines16.1 Refer to Guide D 68
44、09 for suggested QA/QC activitiesthat can be used as a part of this method. It is recommendedthat the operator of this method select and perform relevantQA/QC activities like the ones in Guide D 6809 to help insurethe quality of data generated by this method.17. Keywords17.1 BTX concentrates; BTX ex
45、tracts; capillary gas chro-matography; commercial toluene; crude benzene; crude ethyl-benzene; hydrogenated pyrolysis gas; light blending aromaticfeedstock; mixed xylenes; pyrolysis gas4Supporting data are available from ASTM International Headquarters. RequestRR:D16-1025. Supporting data for mixed
46、xylenes are available separately: RequestRR:D161015.TABLE 2 Interlaboratory Precision and Reproducibility forSynthetic Blend SampleNOTE 1This data was calculated after removal of outliers usingPractice E 691.ComponentConcentrationWeight %IntermediatePrecisionReproducibilityNonaromatics 22.447 0.296
47、1.746Benzene 42.891 0.781 1.887Toluene 19.961 0.212 0.715Ethylbenzene 3.061 0.055 0.191Total xylenes 7.921 0.195 0.512C9+ aromatics 4.192 0.169 1.009D6563057TABLE 3 Interlaboratory Precision and Reproducibility forPyrolysis Gasoline SampleNOTE 1This data was calculated after removal of outliers usin
48、gPractice E 691.ComponentConcentrationWeight %IntermediatePrecisionReproducibilityNonaromatics 17.918 0.237 1.394Benzene 36.580 0.666 1.610Toluene 17.117 0.181 0.613Ethylbenzene 1.519 0.027 0.095Total xylenes 6.271 0.154 0.406C9+ aromatics 20.419 0.823 4.917TABLE 4 Interlaboratory Precision and Repr
49、oducibility forExtracted Reformate SampleNOTE 1This data was calculated after removal of outliers usingPractice E 691.ComponentConcentrationWeight %IntermediatePrecisionReproducibilityNonaromatics 0.264 0.003 0.021Benzene 21.015 0.382 0.925Toluene 34.516 0.366 1.236Ethylbenzene 5.473 0.098 0.342Total xylenes 24.173 0.595 1.564C9+ aromatics 14.744 0.594 3.550TABLE 5 Interlaboratory Precision and Reproducibility forHydrogenated Pyrolysis GasolineNOTE 1This data was calculated after removal of outliers usingPractice E 691.ComponentCon
