1、Designation: D6144 17Standard Test Method forAnalysis of AMS (-Methylstyrene) by Capillary GasChromatography1This standard is issued under the fixed designation D6144; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 purityof AMS (-methylstyrene) by gas chromatography. Calibrationof the
3、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, 1-p
4、henyl-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 AMS
5、 can be analyzed over a range of 5 to 800mg/kg by this method. (See Table 1.) The limit of quantitationfor these these impurities averages 4 mg/kg, while the limit ofdetection averages 1.2 mg/kg. (See Table 1.)1.3 In determining the conformance of the test results usingthis method to applicable spec
6、ifications, results shall berounded 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,
7、associated with its use. It is 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 8.1.6 This international standard was developed in accor
8、-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM
9、 Standards:2D3437 Practice for Sampling and Handling Liquid CyclicProductsD4307 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 Hydrocar
10、bons and Related Ma-terialsE29 Practice for Using Significant Digits 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
11、 Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other Document:OSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.120033. Terminology3.1 See Terminology D4790 for definition of terms used inthis test method.4. Summary of Test Method4.1 AMS (-methylstyrene) is analy
12、zed by a gas chromato-graph (GC) equipped with a flame ionization detector (FID). Aprecisely repeatable volume of the sample to be analyzed is1This test method is under the jurisdiction of ASTM Committee D16 onAromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-bility of
13、 Subcommittee D16.07 on Styrene, Ethylbenzene and C9 and C10 AromaticHydrocarbons.Current edition approved June 1, 2017. Published June 2017. Originallyapproved in 1997. Last previous edition approved in 2013 as D6144 13. DOI:10.1520/D6144-17.2For referenced ASTM standards, visit the ASTM website, w
14、ww.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. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Wa
15、shington, 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 StatesThis international standard was developed in accordance with internationally
16、recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1injected onto the gas chromatograph. The peak areas of thei
17、mpurities are measured and converted to concentrations via anexternal standard methodology. Purity by GC (the AMScontent) 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 spec
18、ifications 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.5.2 This test method is useful in determining the purity ofAMS with normal impuri
19、ties 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 instrument having a flameionization detector that can be operated at the conditions
20、 givenin Table 2. The system should have sufficient sensitivity toobtain a minimum peak height response for 10 mg/kg aceto-phenone 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
21、 all significant impurities from AMS. The columndescribed in Table 2 has been used successfully and shall beused as a referee in cases of dispute.6.3 RecorderChromatographic data systems are preferredbut electronic integration may be used if the user can demon-strate that the results are consistent
22、with the precision state-ment. Recorders are not considered adequate for meeting theprecision requirements of this standard.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
23、 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 indicated, it is intended thatall reagents shall conform to the specification of the Committeeon A
24、nalytical 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 permit its use without lessening theaccuracy of the determination.4Reagent Chemicals, American Chem
25、ical 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 Pharmacopeiaand National Formulary, U.S. Ph
26、armacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Summary of Precision Data (mg/kg)Compound Repeatability (r) Reproducibility (R) 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
27、+ 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-Phenyl-2-Butene
28、 (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) 0.33 + 0.76
29、*MBF 0.75 + 0.60*MBF 1 22-Phenylpropion aldehyde (PPA) 0.59 + 0.11*PPA 0.29 + 0.23*PPA 1.5 15-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 Recommended Operating ConditionsDetector flame ionizationInjection Port capillary split
30、terColumn A:Tubing fused silicaStationary phase crosslinked methylsiliconeFilm thickness, m 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 heliumFlow rate,
31、 mls/min 3Split ratio 60:1Sample size, l 1.0D6144 1727.2 Carrier Gas, Makeup, and Detector GasesHelium,hydrogen, nitrogen, or other carrier, makeup and detector gases99.999 % minimum purity. Oxygen in carrier gas less than 1ppm, less than 0.5 ppm is preferred. Purify carrier, makeup,and detector gas
32、es to remove oxygen, water, and hydrocarbons.7.3 Compressed AirPurify air to remove water and hydro-carbons. Air for a FID should contain less than 0.1 ppm THC.7.4 Pure Compounds for CalibartionThe purity of allreagents should be 99.9 % or greater. If the purity is less than99 %, the concentration a
33、nd identification of impurities mustbe known so that the composition of the standard can beadjusted for the presence of the impurities.8. Hazards8.1 Consult current OSHA regulations, suppliers SafetyData Sheets, and local regulations for all materials used in thistest method.9. Sampling and Handling
34、9.1 Sample the material in accordance with Practice D3437.10. 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 to
35、reach equilibrium. SeePractice E1510 for more information on column installation.See Practice E355 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 representative of
36、 thoseexpected in the samples to be analyzed in accordance withPractice D4307. 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 requiredfor im
37、purities 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 methodol-og
38、y 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 2.11.
39、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 ofthr
40、ee 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-butylbenz
41、ene is used for the quantification of unknown impu-rities.12. Procedure12.1 Inject into the gas chromatograph an appropriateamount of sample sufficient to satisfy the sensitivity conditionsdetailed in 6.1 and start the analysis.12.2 Obtain a chromatogram and peak integration report.Fig. 1 illustrate
42、s 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 commercially. However,pure samples of these isomers can be prepared, and testing hasshown that all three isomers
43、 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= concentration of component i, in mg/kg,Ai = peak area of component i, andRfi = response factor for component i.13.3 C
44、alculate the total concentration of all impurities in wt.% as follows:Ct5 Ci/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 nu
45、mbers below the LOD as 1 mg/kg.14.3 Report the purity of AMS to the nearest 0.01 wt. %.15. Precision and Bias515.1 The following criteria should be used to judge theacceptability of results obtained by this test method (95 %confidence level). The precision criteria were derived from anILS that was c
46、onducted using the conditions listed in Table 15Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D16-1022. ContactASTM CustomerService at serviceastm.org.D6144 173FIG. 1 Typical AMS Chromagram, AMS MethodD6144 174which included fi
47、ve laboratories analyzing six samples intriplicate by the same operator on the same day. Practice E691was followed for the design and analysis of the data; the detailsare given in ASTM Research Report RR:D16-1022.15.2 RepeatabilityResults in the same laboratory shouldnot be considered suspect unless
48、 they differ by more than theamounts calculated from the appropriate equations in Table 1.Results differing by less than “r” have a 95 % probability ofbeing correct.15.3 ReproducibilityResults submitted by two laborato-ries should not be considered suspect unless they differ bymore than the amounts
49、calculated from the appropriate equa-tions in Table 1. Results differing by less than “R”havea95%probability of being correct.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.16. Quality Guidelines16.1 Laboratories shall have a quality control system inplace.16.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of s
