1、Designation: D5135 161Standard 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.1NOTETable 3 was editorially corrected in November 2016.1. Scope*1.1 This test method covers the determination of the impu-rities typically foun
3、d in styrene and uses those values todetermine the purity 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 hi
4、gher when using the internal standard procedure.1.3 In determining 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.
5、 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 the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability
6、of regulatorylimitations prior to use. For a specific hazard 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 Hy
7、drocarbons and RelatedChemicalsD6809 Guide for Quality Control 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-shi
8、psE691 Practice for Conducting an Interlaboratory Study toDetermine 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 Terminolo
9、gy D4790 for definitions of terms used inthis test method.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 impu
10、rities relative to that of theinternal standard and the amount 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
11、styrene purity onthe basis of impurities normally present 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
12、 are available.Absolute purity cannot be determined if unknown 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 Aromatic
13、Hydrocarbons.Current edition approved June 1, 2016. Published October 2016. Originallyapproved in 1990. Last previous edition approved in 2014 as D5135 14. DOI:10.1520/D5135-16E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org
14、. 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, Washington, DC 20401, http:/www.access.gpo.gov.*A Summary of Chan
15、ges section appears at the end of this standardCopyright ASTM 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
16、satisfactorily resolved from a neighboring peak if thedistance 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
17、 conditions givenin Table 2. The system shall have sufficient 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 bes
18、atisfactory. Any column can be used that is capable ofresolving 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 c
19、olumn and conditions described in Table 2 have beenused successfully 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
20、for calibration is also excluded. Generally,non-aromatics are 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 re
21、maining non-aromatics would bereported as “Nonaromatics other 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 co
22、mponents,such as cumene or p-diethylbenzene, may be reported 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 inth
23、is region, but they are not common in materials within thescope 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
24、of ReagentReagent grade chemicals shall beused in all tests. 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 de
25、tector gases 99.999 %purity. Oxygen in carrier gas less than 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 % minimu
26、m purity, or other internalstandard, such as n-octane, previously 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 co
27、mmercial styrene. Theseshould be at least 99 % pure as they are to be used fordetermining response factors.9. Hazards9.1 Consult current OSHA regulations, suppliers SafetyData Sheets, and local regulations for all materials used in thisprocedure.4Reagent Chemicals, American Chemical Society Specific
28、ations, 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. Pharmacopeial Conventio
29、n, Inc. (USPC), Rockville,MD.TABLE 1 Impurities Known or Suggested to be Present inCommercial StyreneEthylbenzeneo-xylenem-xylenep-xyleneIsopropylbenzenen-propylbenzenem-ethyltoluenep-ethyltoluene-methylstyrenem-vinyltoluenep-vinyltoluenePhenylacetyleneTABLE 2 Recommended Operating ConditionsCarrier
30、 gas heliumCarrier gas flow rate at 110C, mL/min 1.2Detector 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
31、polyethylene glycol-fused silica capillaryColumn temperature, C 110Chart speed, cm/min 1Sample size, L 0.6D5135 161210. Sampling10.1 Sample the material in accordance with PracticeD3437.11. Preparation of Apparatus11.1 Follow manufacturers instructions for mounting andconditioning the column into th
32、e chromatograph and adjustingthe instrument conditions 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 contai
33、ning approximately99.5 weight % styrene and the expected 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
34、 100mL volumetric flask about three-fourths full of 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
35、Also prepare a sample of the styrene used for thecalibration 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
36、 be used.12.4 Inject an appropriate amount of sample 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:RFi5
37、CiCs!SAiAsi2AbAsbD(1)where:RFi= response factor relative 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
38、 make calibrationmixture,Cs= weight percent internal 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 th
39、e manufacturer of the chromato-graph.13.2 Prepare sample 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, excep
40、t the styrene peak.14.2 Calculate the weight percent 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 percen
41、t.14.3 Calculate the styrene content by subtracting 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 Precisi
42、onThe following criteria should be used tojudge the acceptability (95 % probability level) of resultsobtained by this test method (see Practice E691).16.1.1 The criteria presented in Table 3 and Table 4 werederived from a Interlaboratory Study (ILS) among six labora-tories. The data were run on two
43、days using different operators.16.1.2 The criteria and precision data presented in Table 5were derived from a commercial Proficiency Testing schemeperformed during the years 1997 through 2014 (no formal PTreport available, however data are available to ASTM).16.2 Intermediate Precision (formerly cal
44、ledRepeatability)Results in the same 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
45、in Table 3, Table 4 and Table 5.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D16-1031. ContactASTM CustomerService at serviceastm.org.D5135 161316.4 BiasBias of this test method for the analysis ofstyrene has not been determi
46、ned because no acceptable refer-ence material is available.17. 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 qua
47、lity control practices.17.1.2 A quality control 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 t
48、est results.17.1.4 When there are no QA/QC protocols 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.
49、1 Typical Chromatogram (see Table 2)TABLE 3 ILS Precision for Styrene and Impurities at StatedLevelsComponentConcentration,weight %IntermediatePrecision,weight %Reproducibility,weight %Styrene 99.74 0.017 0.054-methylstyrene 0.028 0.001 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 0.125 0.005 0.007o-xylene 0.030 0.001 0.042 Editorially corrected.TABLE 4 ILS Precision for High Purity Styrene and Impurities atStated LevelsComponentConcentration,weight %Interme
