1、Designation: D 6144 08Standard Test Method forAnalysis of AMS (a-Methylstyrene) by Capillary GasChromatography1This standard is issued under the fixed designation D 6144; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、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 the purityofAMS (a-methylstyrene) by gas chromatography. Calibrationof t
3、he gas chromatography system is done by the externalstandard calibration technique.1.2 This test method has been found applicable to themeasurement of impurities such as cumene, 3-methyl-2-cyclopentene-1-one, n-propylbenzene, tert-butylbenzene, sec-butylbenzene, cis-2-phenyl-2-butene, acetophenone,
4、1-phenyl-1-butene, 2-phenyl-2-propanol, trans-2-phenyl-2-butene,m-cymene, p-cymene, and phenol, which are common to themanufacturing process of AMS. The method has also beenfound applicable for the determination of para-tertiary-butylcatechol typically added as a stabilizer to AMS. Theimpurities in
5、AMS can be analyzed over a range of 5 to 800mg/kg by this method. (See Table 1.) The limit of detection forthese impurities is typically in the range of 5 to 10 mg/kg. (SeeTable 1.)1.3 In determining the conformance of the test results usingthis method to applicable specifications, results shall ber
6、ounded 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 the safetyconcerns, if any, associated with its use. It i
7、s the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use. For specific hazard statements, seeSection 8.2. Referenced Documents2.1 ASTM Standards:2D 3437 Practice for Sampling and Handlin
8、g Liquid CyclicProductsD 4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD 4790 Terminology of Aromatic Hydrocarbons and Re-lated ChemicalsD 6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Us
9、ing 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 Precision of a Test MethodE 1510 Practice for Installing Fused Silica Open TubularCapill
10、ary Columns in Gas Chromatographs2.2 Other Document:OSHA Regulations, 29CFR paragraphs 1910.1000 and1910.120033. Terminology3.1 See Terminology D 4790 for definition of terms used inthis test method.4. Summary of Test Method4.1 AMS (a-methylstyrene) is analyzed by a gas chromato-graph (GC) equipped
11、with a flame ionization detector (FID). 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 AMS1This test method is under t
12、he jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.07 on Styrene, Ethylbenzene and C9 and C10 AtomaticHydrocarbons.Current edition approved June 1, 2008. Published June 2008. Originallyapproved in 1997. Last previou
13、s edition approved in 2004 as D 6144 - 04.2For 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
14、. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.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 1
15、9428-2959, United States.content) is calculated by subtracting the sum of the impuritiesfrom 100.00. Results are reported in weight percent.5. Significance and Use5.1 This test method is suitable for setting specifications onthe materials referenced in 1.2 and for use as an internal qualitycontrol t
16、ool where AMS is produced or is used in a manufac-turing process. It may also be used in development or researchwork involving AMS.5.2 This test method is useful in determining the purity ofAMS with normal impurities present. If extremely high boilingor unusual impurities are present in the AMS, thi
17、s test methodwould not necessarily detect them and the purity calculationwould 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
18、height response for 10 mg/kg ac-etophenone of 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 AMS. The columndescribed in Table 2 has been used succe
19、ssfully. Unless theanalyst can be sure of peak identity, for example by gaschromatography-mass spectrometry (GC-MS), the use of thecolumn in Table 2 is strongly recommended.6.3 RecorderElectronic integration is recommended.6.4 InjectorThe specimen must be precisely and repeat-ably injected into the
20、gas chromatograph.An automatic sampleinjection device is highly recommended. Manual injection canbe employed if the precision stated in Table 1 can be reliablyand consistently satisfied.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise
21、 indicated, it is intended thatall reagents shall conform to the specification of the Committeeon Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to
22、permit its use without lessening theaccuracy of the determination.7.2 Carrier GasHelium, hydrogen, nitrogen, or othercarrier, makeup and detector gases 99.999 % minimum purity.Oxygen in carrier gas less than 1 ppm, less than 0.5 ppm ispreferred. Purify carrier, makeup, and detector gases to removeox
23、ygen, water, and hydrocarbons.7.3 Compressed AirPurify air to remove water and hy-drocarbons. Air for a FID should contain less than 0.1 ppmTHC.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted
24、 by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Summary of Precision Data (mg/kg)Compound Repeatability Reproduci
25、bility Range StudiedAcetone 1.61 + 0.035*Acetone 0.47 + 1.10*Acetone 0.5 26Cumene 0.46 + 0.031*Cumene 7.88 + 0.19*Cumene 45 290nPropylbenzene (NPB) 2.11 + 0.03*NPB 7.81 + 0.37*NPB 55 195Phenol 1.84 3.65 + 0.58*Phenol 1 40tertButylbenzene (TBB) 1.22 + 0.035*TBB 3.63 + 0.087*TBB 150 650secButylbenzene
26、 (SBB) 4.23 + 0.019*SBB 21.60 + 0.25*SBB 200 765mCymene 0.31 + 0.035*mCymene 2.34 + 0.35*mCymene 2 50oCymene 1.63 8.00 29 31pCymene 5.12 15.79 10 18cis-2-Phenyl-2-Butene (CPB) 0.17 + 0.030*CPB 5.39 + 0.11*CPB 50 225trans-2-Phenyl-2-Butene (TPB) 1.57 0.54 + 0.20*TPB 19 701-Phenyl-1-Butene (PB) 4.00 +
27、 0.018*PB 0.17 + 0.19*PB 0.2 735Acetophenone (AP) 1.09 + 0.15*AP 1.17 + 0.63*AP 15 115para-tert-Butylcatechol (PTBC) 2.21 17.82 10 192-Methylbenzofuran (MBF) 0.33 + 0.76*MBF 0.75 + 0.60*MBF 1 22-Phenylpropion aldehyde (PPA) 0.59 + 0.11*PPA 0.29 + 0.23*PPA 1.5 15a-Methylstyrene Oxide (AMSO) 4.61 6.51
28、 + 0.23*AMSO 13 32DimethylBenzyl Alcohol (DMBA) 0.38 0.55 + 2.03*DMBA 0.1 1TABLE 2 Instrumental ParametersDetector flame ionizationInjection Port capillary splitterColumn A:Tubing fused silicaStationary phase crosslinked methylsiliconeFilm thickness, 4m 1.0Length, m 60Diameter, mm 0.32Temperatures:I
29、njector, C 250Detector, C 300Oven, C 85 hold for 13 minRamp 1 = 6C/min to 125C,hold for 2 minRamp 2 = 30C/min to 250C,hold for 7.5 minCarrier gas heliumFlow rate, mls/min 3Split ratio 60:1Sample size, 4l 1.0D61440827.4 Hydrogen99.999 % minimum purity.8. Hazards8.1 Consult current OSHA regulations, s
30、uppliers MaterialSafety Data Sheets, and local regulations for all materials usedin this test method.9. Sampling and Handling9.1 Sample the material in accordance with PracticeD 3437.10. Preparation of Apparatus10.1 Follow manufacturers instructions for mounting andconditioning the column into the c
31、hromatograph and adjustingthe instrument to the conditions described in Table 2 allowingsufficient time for the equipment to reach equilibrium. SeePractice E 1510 for more information on column installation.See Practice E 355 for additional information on gas chroma-tography practices and terminolog
32、y.11. Calibration11.1 Prepare a synthetic mixture of high purity AMS con-taining impurities at concentrations representative of thoseexpected in the samples to be analyzed in accordance withPractice D 4307. The weight of each hydrocarbon impuritymust be measured to the nearest 0.1 mg. Because the av
33、ail-ability of stock AMS with a purity higher than 99.80 % isproblematic, the method of standard additions may be requiredfor impurities such as tert-butylbenzene and n-proplybenzene,as well as for a number of the other impurities listed in 1.2 thatare commonly present. In addition, nearly all comme
34、rciallyavailable AMS is stabilized with 10 to 30 mg/kg of para-tertiary-butylcatechol, requiring a standard addition methodol-ogy for this component as well unless AMS can be obtainedsafely and directly from the point of manufacture.11.2 Inject the resulting solution from 11.1 into the gaschromatogr
35、aph, collect and process the data. A typical chro-matogram is illustrated in Fig. 1 based on the conditions listedin Table 2.11.3 Determine the response factor for each impurity in thecalibration mixture as follows:Rfi 5 Ci/Ai (1)where:Rfi = response factor for impurity i,Ci = concentration of impur
36、ity i in the calibration mixture,andAi = peak area of impurity i.11.4 Initially analyze the calibration solution a minimum ofthree times and calculate an average Rfi. Subsequent calibra-tions may be a single analysis as long as the Rfis for allcomponents of interest are within 65 % of the initial va
37、lidationRfis.A“rolling” average as defined by most modern chromato-graphic software may also be used. The Rfi for tert-butylbenzene is used for the quantification of unknown impu-rities.12. Procedure12.1 Inject into the gas chromatograph an appropriateamount of sample as previously determined accord
38、ing to 6.1and start the analysis.12.2 Obtain a chromatogram and peak integration report.Fig. 1 illustrates a typical analysis of AMS using the columnand conditions outlined in Table 2.13. Calculations13.1 Of the impurities identified in AMS, only the butenyl-benzene isomers are not available commerc
39、ially. However,pure samples of these isomers can be prepared, and testing hasshown that all three isomers have the same response factor65 %, and that it is equivalent to that for tert-butylbenzene65%.513.2 Calculate the concentration of each impurity as fol-lows:Ci5 Ai! Rfi! (2)where:Ci= concentrati
40、on of component i, in mg/kg,Ai = peak area of component i, andRfi = response factor for component i.13.3 Calculate the total concentration of all impurities in wt.% as follows:Ct5SCi/10000 (3)where:Ct= total concentration of all impurities.13.4 Calculate the purity of AMS as follows:AMS, weight perc
41、ent 5 100.00 2 Ct(4)14. Report14.1 Report the individual impurities to the nearest 0.1mg/kg.14.2 Report the purity of AMS to the nearest 0.01 wt. %.15. Precision and Bias515.1 The criteria in Table 1 should be used to judge theacceptability at the 95 % probability level of the resultsobtained by thi
42、s test method. The criteria were derived from aninterlaboratory study between five laboratories on six samplesrun in triplicate by the same operator on the same day. Theresults were derived using the protocol set forth in PracticeE 691.15.2 RepeatabilityResults in the same laboratory shouldnot be co
43、nsidered suspect unless they differ by more than theamounts calculated from the appropriate equations in Table 1.15.3 ReproducibilityResults submitted by two laborato-ries should not be considered suspect unless they differ bymore than the amounts calculated from the appropriate equa-tions in Table
44、1.15.4 BiasSince there is no accepted reference materialsuitable for determining the bias in this test method formeasuring these impurities, bias has not been determined.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D161022.D6
45、144083FIG. 1 Typical AMS Chromagram, AMS MethodD614408416. Quality Guidelines16.1 Refer to Guide D 6809 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
46、 to help ensurethe quality of data generated by this method.17. Keywords17.1 acetophenone; alpha methylstyrene; AMS; analysis bygas chromatography; benzene; butenylbenzene; butylbenzene;catechol; cumene; cymene; phenol; propylbenzene; tolueneSUMMARY OF CHANGESCommittee D14 has identified the locatio
47、n of selected changes to this standard since the last issue(D 6144 - 04) that may impact the use of this standard. (Approved June 1, 2008.)(1) Section 7 Modified description of gases to meet currenteditorial standards.ASTM International takes no position respecting the validity of any patent rights
48、asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any tim
49、e by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee o
