1、Designation: D5135 14Standard Test Method forAnalysis of Styrene by Capillary Gas Chromatography1This standard is issued under the fixed designation D5135; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 impu-rities typically found in styrene and uses those values todetermine the purity
3、 of styrene by difference by gas chroma-tography. Typical impurities in commercial styrene are foundin Table 1.1.2 This test method is applicable to impurity concentra-tions in the range of 0.001 to 1.00 % and for styrene purities of99 % or higher when using the internal standard procedure.1.3 In de
4、termining the conformance of the test results usingthis method to applicable specifications, results shall berounded off in accordance with the rounding-off method ofPractice E29.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstanda
5、rd.1.5 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 applicability of regulatorylimitations prior to use. For a specific haz
6、ard statement, seeSection 9.2. Referenced Documents2.1 ASTM 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 Co
7、ntrol and Quality AssuranceProcedures for Aromatic Hydrocarbons 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 t
8、oDetermine the Precision of a Test MethodE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs2.2 Other DocumentOSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.120033. Terminology3.1 See Terminology D4790 for definitions of terms used inthis test method
9、.4. Summary of Test Method4.1 In this test method, the chromatogram peak area for eachimpurity is compared to the peak area of the internal standard(n-heptane or other suitable known) added to the sample. Fromthe response factors of these impurities relative to that of theinternal standard and the a
10、mount of internal standard added,the concentration of the impurities are calculated. The styrenecontent is obtained by subtracting the total amount of allimpurities from 100.00.5. Significance and Use5.1 This test method is designed to obtain styrene purity onthe basis of impurities normally present
11、 in styrene and may beused for final product inspections and process control.5.2 This test method will detect the impurities shown inTable 1, non-aromatic hydrocarbons containing ten carbons orless, and others where specific impurity standards are available.Absolute purity cannot be determined if un
12、known impuritiesare present.1This test method is under the 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 AromaticHydrocarbons.Current edition approved Feb. 1, 2014. Publi
13、shed February 2014. Originallyapproved in 1990. Last previous edition approved in 2007 as D5135 07. DOI:10.1520/D5135-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refe
14、r 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, Washington, DC 20401, http:/www.access.gpo.gov.*A Summary of Changes section appears at the end of this standardCopyright AS
15、TM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Interferences6.1 The internal standard chosen must be satisfactorilyresolved from any impurity as well as the product peak.Apeakwill be satisfactorily resolved from a neighboring peak if thedista
16、nce from the valley to the baseline between the two peaksis not greater than 50 % of the peak height of the smaller of thetwo peaks.7. Apparatus7.1 Gas ChromatographAny instrument having a flameionization detector that can be operated at the conditions givenin Table 2. The system shall have sufficie
17、nt sensitivity to obtaina minimum peak height response for 0.001 weight % impurityof twice the height of the background noise.7.2 ColumnA capillary column containing a stationaryphase of cross-linked polyethylene glycol has been found to besatisfactory. Any column can be used that is capable ofresol
18、ving all significant impurities from styrene and from theinternal standard. The choice of column is based on resolutionrequirements. Any column may be used that is capable ofresolving all significant impurities from the major component.The column and conditions described in Table 2 have beenused suc
19、cessfully and shall be used as a referee in cases ofdispute.7.2.1 “Total non-aromatics” are defined as all componentseluting before o-xylene, excluding benzene, toluene,ethylbenzene, p-xylene, m-xylene, and cumene. The internalstandard used for calibration is also excluded. Generally,non-aromatics a
20、re summed and reported as a group. In certaincases, one or more individual non-aromatic components, suchas 1,4-dioxane, may be reported separately. In those cases, thegrouping would not include the separately reportedcomponent(s), and the remaining non-aromatics would bereported as “Nonaromatics oth
21、er than (component(s).”7.2.2 “Total C9plus aromatics” are defined as cumene, plusall components eluting after o-xylene. Generally, C9plusaromatics are summed and reported as a group. In certaincases, one or more individual C9plus aromatic components,such as cumene or p-diethylbenzene, may be reporte
22、d sepa-rately. In those cases, the grouping would not include theseparately reported component(s) and the remaining C9plusaromatics would be reported as “C9plus aromatics other than(component(s).” Very heavy non-aromatics may also elute inthis region, but they are not common in materials within thes
23、cope of Committee D16, and are not considered in thedefinition.7.3 RecorderElectronic integration, with tangent capabili-ties is recommended.7.4 100-mL Volumetric Flask.7.5 Microsyringes, assorted volumes.8. Reagents and Materials8.1 Purity of ReagentReagent grade chemicals shall beused in all tests
24、. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee onAnalytical Reagents of theAmerican Chemical Society,4where such specifications are available.8.2 Carrier Gas, makeup and detector gases 99.999 %purity. Oxygen in carrier gas less tha
25、n 1 ppm, less than 0.5 ppmis preferred. Purify carrier, makeup and detector gases toremove oxygen, water, and hydrocarbons.8.3 Air, purify to remove hydrocarbons and water. Airshould contain less than 0.1 ppm THC.8.4 n-Heptane, 99.0 % minimum purity, or other internalstandard, such as n-octane, prev
26、iously analyzed to be free ofcompounds coeluting with impurities in the sample.8.5 Styrene, the highest purity available, but not less than99.7 %.8.6 Pure Compounds, for calibration, shall be those com-pounds that are typically present in commercial styrene. Theseshould be at least 99 % pure as they
27、 are to be used fordetermining response factors.9. Hazards9.1 Consult current OSHA regulations, suppliers MaterialSafety Data Sheets, and local regulations for all materials usedin this procedure.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC.
28、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. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Impurities Kn
29、own or Suggested to be Present inCommercial StyreneEthylbenzeneo-xylenem-xylenep-xyleneIsopropylbenzenen-propylbenzenem-ethyltoluenep-ethyltoluene-methylstyrenem-vinyltoluenep-vinyltoluenePhenylacetyleneTABLE 2 Recommended Operating ConditionsCarrier gas heliumCarrier gas flow rate at 110C, mL/min 1
30、.2Detector flame ionizationDetector temperature, C 240Injection port temperature, C 230Hydrogen flow rate, mL/min 30Air flow rate, mL/min 275Make up gas nitrogenMake up gas flow rate, mL/min 23Split flow, mL/min 150Column 60 m 0.32 mm ID 0.5 mbonded polyethylene glycol-fused silica capillaryColumn t
31、emperature, C 110Chart speed, cm/min 1Sample size, L 0.6D5135 14210. Sampling10.1 Sample the material in accordance with PracticeD3437.11. Preparation of Apparatus11.1 Follow manufacturers instructions for mounting andconditioning the column into the chromatograph and adjustingthe instrument conditi
32、ons described in Table 2, allowingsufficient time for the equipment to reach equilibrium. SeePractices E355 and E1510 for additional information on gaschromatographic practices and terminology.12. Calibration12.1 Prepare a calibration mixture containing approximately99.5 weight % styrene and the exp
33、ected significant impuritiesat their expected concentration (see Practice D4307). Weigh allcomponents to the accuracy required to calculate the concen-tration of each to the nearest 0.001 %.12.2 With a microsyringe, add 50 L of internal standard toa 100mL volumetric flask about three-fourths full of
34、 calibra-tion mixture. Mix well. Add calibration mixture to mark andagain mix well. If n-heptane is used as the internal standard,using a density of 0.684 for n-heptane and 0.906 for styrene,this solution will contain 0.0377 weight % n-heptane.12.3 Also prepare a sample of the styrene used for theca
35、libration blend with and without n-heptane to determine theconcentration of existing impurities and interfering compoundswith internal standard. If impurities in the styrene emerge withthe chosen internal standard, an alternate internal standardmust be used.12.4 Inject an appropriate amount of sampl
36、e into the chro-matograph and obtain a chromatogram.12.5 Measure the areas of all peaks, including the internalstandard, except the styrene peak.12.6 Calculate the response factors for each impurity rela-tive to the internal standard as follows:RFi5CiCs!SAiAsi2AbAsbD(1)where:RFi= response factor rel
37、ative to the internal standard,Asi= area of internal standard in calibration mixture,Ai= area of impurity peak in calibration mixture,Asb= area of internal standard in styrene used in makingcalibration mixture,Ab= area of impurity in styrene used to make calibrationmixture,Cs= weight percent interna
38、l standard in calibrationmixture, andCi= weight percent impurity in calibration mixture.13. Procedure13.1 Establish stable instrument operation at the prescribedor selected operating conditions. Reference should be made toinstructions provided by the manufacturer of the chromato-graph.13.2 Prepare s
39、ample as described in 12.2.13.3 Inject appropriate amount of sample into the chromato-graph and obtain the chromatogram.Atypical chromatogram isshown in Fig. 1.14. Calculation14.1 Measure the areas of all peaks, including the internalstandard, except the styrene peak.14.2 Calculate the weight percen
40、t of the individualimpurities, Ci, as follows:Ci5Ai!RFi!Cs!As(2)where:Ai= area of impurity,As= area of internal standard,RFi= response factor for impurity, relative to the internalstandard, andCs= concentration of internal standard, in weight percent.14.3 Calculate the styrene content by subtracting
41、 the sum ofthe impurities from 100.00. Styrene weight per-cent = 100.00 (sum of impurities).15. Report15.1 Report the concentration of impurities to the nearest0.001 % and the styrene content to the nearest 0.01 %.16. Precision and Bias516.1 PrecisionThe following criteria should be used tojudge the
42、 acceptability (95 % probability level) of resultsobtained by this test method (see Practice E691). The criteriawere derived from a round robin among six laboratories. Thedata were run on two days using different operators.16.2 Intermediate Precision (formerly calledRepeatability)Results in the same
43、 laboratory should not beconsidered suspect unless they differ by more than the normalamount shown in Table 3 and Table 4.16.3 ReproducibilityThe results by each of two laborato-ries should not be considered suspect unless they differ bymore than the amount shown in Table 3 and Table 4.16.4 BiasBias
44、 of this test method for the analysis ofstyrene has not been determined because no acceptable refer-ence material is available.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D16-1031. ContactASTM CustomerService at serviceastm.
45、org.D5135 14317. Quality Guidelines17.1 Laboratories shall have a quality control system inplace.17.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality control practices.17.1.2 A quality contro
46、l sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.17.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test results.17.1.4 When there are no QA/QC pro
47、tocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical quality control practices.18. Keywords18.1 analysis by gas chromatography; impurities in styrene;purity of styrene; styrene; styrene monomerFIG. 1 Typical Chromatogram (see Table 2)TABLE 3 Pr
48、ecision for Styrene and Impurities at Stated LevelsComponentConcentration,weight %IntermediatePrecision,%Reproducibility,%Styrene 99.74 0.017 0.054-methylstyrene 0.028 0.0001 0.004Isopropylbenzene 0.008 0.001 0.001n-propylbenzene 0.004 0.0003 0.001m- and p-ethyltoluene 0.014 0.001 0.005p, m-xylene 0
49、.125 0.005 0.007o-xylene 0.030 0.001 0.042TABLE 4 Precision for High Purity Styrene and Impurities atStated LevelsComponentConcentration,weight %IntermediatePrecision,%Reproducibility,%Styrene 99.96 0.024 0.033Ethylbenzene 0.014 0.003 0.004-methylstyrene 0.007 0.002 0.003D5135 144SUMMARY OF CHANGESCommittee D16 has identified the location of selected changes to this standard since the last issue (D513507)that may impact the use of this standard. (Approved February 1, 2014.)(1) Table 2 was renamed and Section 7 was revised. (2) Section 17
