1、Designation: D 6144 04Standard 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the purityof AMS (a-methylstyrene) by gas chromatography. Calibrationof
3、 the 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 i
5、n 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 b
6、erounded off in accordance with the rounding-off method ofPractice E 29.1.4 This standard does not purport to address all the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the ap
7、plicability of regulatorylimitations prior to use. For specific hazard statements, seeSection 8.2. Referenced Documents2.1 ASTM Standards:2D 3437 Practice for Sampling and Handling Liquid CyclicProductsD 4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD 4790 Terminology
8、of Aromatic Hydrocarbons and Re-lated ChemicalsD 6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 355 Practice for Gas Chromatography Ter
9、ms and Rela-tionshipsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other Document:OSHA Regulations, 29 CFR, paragraphs 1910.1000 and1910.120033. Termi
10、nology3.1 See Terminology D 4790 for definition of terms used inthis test method.4. Summary of Test Method4.1 AMS (alpha-methylstyrene) is analyzed by a gas chro-matograph (GC) equipped with a flame ionization detector(FID). A precisely repeatable volume of the sample to beanalyzed is injected onto
11、the gas chromatograph. The peakareas of the impurities are measured and converted to concen-trations via an external standard methodology. Purity by GC(the AMS content) is calculated by subtracting the sum of theimpurities from 100.00. Results are reported in weight percent.5. Significance and Use5.
12、1 This test method is suitable for setting specifications onthe materials referenced in 1.2 and for use as an internal qualitycontrol tool where AMS is produced or is used in a manufac-turing process. It may also be used in development or researchwork involving AMS.1This test method is under the jur
13、isdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.07 on Styrene, Ethylbenzene, and C9and C10AromaticHydrocarbons.Current edition approved Jan. 1, 2004. Published January 2004. Originallyapproved in 1997. Last previous ed
14、ition approved in 1997 as D 6144 - 97.2For 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. Go
15、vernment Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.1*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.5.2 T
16、his test method is useful in determining the purity ofAMS with normal impurities present. If extremely high boilingor unusual impurities are present in the AMS, this test methodwould not necessarily detect them and the purity calculationwould be erroneous.6. Apparatus6.1 Gas ChromatographAny instrum
17、ent 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 10 mg/kg ac-etophenone of twice the height of the signal background noise.6.2 ColumnsThe choice of column is based o
18、n resolutionrequirements. Any column may be used that is capable ofresolving all significant impurities from AMS. The columndescribed in Table 2 has been used successfully. Unless theanalyst can be sure of peak identity, for example by gaschromatography-mass spectrometry (GC-MS), the use of thecolum
19、n 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 gas chromatograph. An automatic sampleinjection device is highly recommended. Manual injection canbe employed if the precision stated in
20、 Table 1 can be reliablyand consistently satisfied.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemical shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specification of the Committeeon Analytical Reagents of the American Ch
21、emical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Carrier Gas Chromatographic grade helium is rec-ommended.7.3 Compr
22、essed Air Chromatographic grade.7.4 HydrogenHigh purity.8. Hazards8.1 Consult current OSHA regulation, suppliers 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 3437.4Reagent Chem
23、icals, American Chemical Society Specifications,AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals,BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia andNational
24、Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.TABLE 1 Summary of Precision Data (mg/kg)Compound Repeatability Reproducibility 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 + 0.0
25、3*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 (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-Phen
26、yl-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 + 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)
27、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 15Alpha-Methylstyrene Oxide (AMSO) 4.61 6.51 + 0.23*AMSO 13 32DimethylBenzyl Alcohol (DMBA) 0.38 0.55 + 2.03*DMBA 0.1 1TABLE 2 Instrumental ParametersDetector flame ionizationInjection Port capillar
28、y splitterColumn A:Tubing fused silicaStationary phase crosslinked methylsiliconeFilm thickness, 4m 1.0Length, m 60Diameter, mm 0.32Temperatures:Injector, 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 heliumFl
29、ow rate, mls/min 3Split ratio 60:1Sample size, 4l 1.0D614404210. Preparation of Apparatus10.1 Follow manufacturers instructions for mounting andconditioning the column into the chromatograph and adjustingthe instrument to the conditions described in Table 2 allowingsufficient time for the equipment
30、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 terminology.11. Calibration11.1 Prepare a synthetic mixture of high purity AMS con-taining impurities at concentrations representati
31、ve 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 avail-ability of stock AMS with a purity higher than 99.80 % isproblematic, the method of standard additions may be required
32、for 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 commerciallyavailable AMS is stabilized with 10 to 30 mg/kg of para-tertiary-butylcatechol, requiring a standard addition metho
33、dol-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 gaschromatograph, collect and process the data. A typical chro-matogram is illustrated in Fig. 1 based on the conditions listedin Table
34、 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 impurity i in the calibration mixture,andAi = peak area of impurity i.11.4 Initially analyze the calibration solution a minimum
35、 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 validationRfis. A “rolling” average as defined by most modern chromato-graphic software may also be used. The Rfi for tert-b
36、utylbenzene is used for the quantification of unknown impu-rities.12. Procedure12.1 Inject into the gas chromatograph an appropriateamount of sample as previously determined according to 6.1and start the analysis.12.2 Obtain a chromatogram and peak integration report.Fig. 1 illustrates a typical ana
37、lysis 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 commercially. However,pure samples of these isomers can be prepared, and testing hasshown that all three isomers have the same
38、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= concentration of component i, in mg/kg,Ai = peak area of component i, andRfi = response factor for component i.13.3 Calculate the t
39、otal 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 percent 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 AM
40、S 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 this test method. The criteria were derived from aninterlaboratory study between five laboratories on six samplesrun in tri
41、plicate 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 considered suspect unless they differ by more than theamounts calculated from the appropriate equations in Table 1.15.3 Re
42、producibilityResults 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 1.15.4 BiasSince there is no accepted reference materialsuitable for determining the bias in this test method formeasuri
43、ng these impurities, bias has not been determined.16. 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 to h
44、elp 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; toluene5Supporting data are available from ASTM International Headquar
45、ters. RequestRR:D161022.D6144043FIG. 1 Typical AMS Chromagram, AMS MethodD6144044SUMMARY OF CHANGESCommittee D16 has identified the location of selected changes to this standard since the last issue(D 6144 - 97) that may impact the use of this standard.(1) Section 1 Modified Scope and other sections
46、 to reflectexternal standard and broader scope of measured components(2) Section 2 Practices D 4307 and E 691 were added asreferences.(3) Section 6 Added 6.4 on injection technique.(4) Section 7 Deleted 7.1.1 referencing n-octane as internalstandard.(5) Section 11 Modified extensively to reflect ext
47、ernalstandard methodology.(6) Section 13 All reference to total carbon numbersremoved, modified extensively to reflect external standardmethodology.(7) Section 15 Updated to reflect results of ILS and statisticsgenerated by B.J. Lane following Practice E 691.(8) Section 16 Converted to Quality Guide
48、lines section.(9) Section 17 Additional components added to keywords.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of an
49、y such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time 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 theresponsib
