1、Designation: D6144 13Standard 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 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 beroun
6、ded 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 is t
7、he 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:2D3437 Practice for Sampling and Handling Li
8、quid 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 Hydrocarbons and Related Ma-terialsE29 Practice for Using Signi
9、ficant 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 Installing Fused Silica Open TubularCapillary Columns
10、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 analyzed by a gas chromato-graph (GC) equipped with a flame
11、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 the jurisdicti
12、on of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.07 on Styrene, Ethylbenzene and C9 and C10 AromaticHydrocarbons.Current edition approved June 1, 2013. Published June 2013. Originallyapproved in 1997. Last previous edition app
13、roved in 2012 as D6144 12. DOI:10.1520/D6144-13.2For 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 fr
14、om U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, 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,
15、PA 19428-2959. United States1content) 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 qualitycontr
16、ol 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 impurities present. If extremely high boilingor unusual impurities are present in the AMS,
17、 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 givenin Table 2. The system should have sufficient sensitivity toobtain a minimum p
18、eak 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 all significant impurities from AMS. The columndescribed in Table 2 has been used s
19、uccessfully and shall beused as a referee in cases of dispute.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
20、 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 Analytical Re
21、agents 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.7.2 Carrier Gas, Makeup, and Detector GasesHe
22、lium,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 gases to remove oxygen, water, and hydrocarbons.7.3 Compressed AirPurify air to remove water and hydr
23、o-carbons. Air for a FID should contain less than 0.1 ppm THC.4Reagent Chemicals, 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, B
24、DH 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 (r) Reproducibility (R) Range StudiedAcetone 1.61 + 0.035*Acetone 0.47 + 1.10*Acetone 0.5 2
25、6Cumene 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 (SBB) 4.23 + 0.019*SBB 21.60 + 0.25*SBB 200 765mCymene 0.31 + 0.035*mCyme
26、ne 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 + 0.018*PB 0.17 + 0.19*PB 0.2 735Acetophenone (AP) 1.09 + 0.15*AP 1.17 + 0.
27、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 15-Methylstyrene Oxide (AMSO) 4.61 6.51 + 0.23*AMSO 13 32DimethylBenzyl Alcohol (DMBA) 0.38 0.55 + 2.03*DMBA 0.1 1
28、TABLE 2 Recommended Operating ConditionsDetector flame ionizationInjection Port capillary splitterColumn 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/
29、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, l 1.0D6144 1327.4 Pure Compounds for CalibartionThe purity of allreagents should be 99.9 % or greater. If the purity is less than99 %, the concentration and identific
30、ation 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 MaterialSafety Data Sheets, and local regulations for all materials usedin this test method.9. Sampling and Handling9.1
31、 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 rea
32、ch 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 th
33、oseexpected 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 impur
34、ities 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-ogy f
35、or 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 2.11.3 D
36、etermine 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 ofthree
37、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-butylbenzene
38、 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 illustrates a
39、 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 ha
40、ve 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 Calc
41、ulate 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 the p
42、urity 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 conducted using the conditions listed in Table 1w
43、hich included five 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 considere
44、d suspect unless they differ by more than the5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D16-1022.D6144 133FIG. 1 Typical AMS Chromagram, AMS MethodD6144 134amounts calculated from the appropriate equations in Table 1.Result
45、s 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 calculated from the appropriate equa-tions in Table 1. Results differing by less than “R”havea95
46、%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
47、 performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality control practices.16.1.2 A quality control sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.16
48、.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test results.16.1.4 When there are no QA/QC protocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical qualit
49、y control practices.17. Keywords17.1 acetophenone; alpha methylstyrene; AMS; analysis bygas chromatography; benzene; butenylbenzene; butylbenzene;catechol; cumene; cymene; phenol; propylbenzene; tolueneSUMMARY OF CHANGESCommittee D16 has identified the location of selected changes to this standard since the last issue (D614412)that may impact the use of this standard. (Approved June 1, 2013.)(1) Verbiage in 12.1 was modified to make it clearer.Committee D16 has identified the location of selected changes to
