1、Designation: D5135 14D5135 16Standard 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 re
2、vision. 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 impurities typically found in styrene and uses those values to determinethe
3、 purity of styrene by difference by gas chromatography. Typical impurities in commercial styrene are found in Table 1.1.2 This test method is applicable to impurity concentrations in the range of 0.001 to 1.00 % and for styrene purities of 99 %or higher when using the internal standard procedure.1.3
4、 In determining the conformance of the test results using this method to applicable specifications, results shall be roundedoff in accordance with the rounding-off method of Practice E29.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in t
5、his standard.1.5 This standard does not purport to address all the safety concerns, if any, associated with its use. It is the responsibility ofthe user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For a
6、specific hazard statement, see Section 9.2. Referenced Documents2.1 ASTM Standards:2D3437 Practice for Sampling and Handling Liquid Cyclic ProductsD4307 Practice for Preparation of Liquid Blends for Use as Analytical StandardsD4790 Terminology of Aromatic Hydrocarbons and Related ChemicalsD6809 Guid
7、e for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related MaterialsE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE355 Practice for Gas Chromatography Terms and RelationshipsE691 Practice for Conducting an Interla
8、boratory Study to Determine the Precision of a Test MethodE1510 Practice for Installing Fused Silica Open Tubular Capillary Columns in Gas Chromatographs2.2 Other DocumentOSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.1200 33. Terminology3.1 See Terminology D4790 for definitions of terms use
9、d in this test method.4. Summary of Test Method4.1 In this test method, the chromatogram peak area for each impurity is compared to the peak area of the internal standard(n-heptane or other suitable known) added to the sample. From the response factors of these impurities relative to that of theinte
10、rnal standard and the amount of internal standard added, the concentration of the impurities are calculated. The styrene contentis obtained by subtracting the total amount of all impurities from 100.00.1 This test method is under the jurisdiction of ASTM Committee D16 on Aromatic Hydrocarbons and Re
11、lated Chemicals and is the direct responsibility of SubcommitteeD16.07 on Styrene, Ethylbenzene and C9 and C10 Aromatic Hydrocarbons.Current edition approved Feb. 1, 2014June 1, 2016. Published February 2014October 2016. Originally approved in 1990. Last previous edition approved in 20072014 asD5135
12、 07.D5135 14. DOI: 10.1520/D5135-14.10.1520/D5135-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website
13、.3 Available 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.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have
14、been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official docum
15、ent.*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 States15. Significance and Use5.1 This test method is designed to obtain styrene purity on the basis of impurities normally
16、present in styrene and may be usedfor final product inspections and process control.5.2 This test method will detect the impurities shown in Table 1, non-aromatic hydrocarbons containing ten carbons or less, andothers where specific impurity standards are available. Absolute purity cannot be determi
17、ned if unknown impurities are present.6. Interferences6.1 The internal standard chosen must be satisfactorily resolved from any impurity as well as the product peak. A peak will besatisfactorily resolved from a neighboring peak if the distance from the valley to the baseline between the two peaks is
18、 not greaterthan 50 % of the peak height of the smaller of the two peaks.7. Apparatus7.1 Gas ChromatographAny instrument having a flame ionization detector that can be operated at the conditions given inTable 2. The system shall have sufficient sensitivity to obtain a minimum peak height response fo
19、r 0.001 weight % impurity oftwice the height of the background noise.7.2 ColumnA capillary column containing a stationary phase of cross-linked polyethylene glycol has been found to besatisfactory. Any column can be used that is capable of resolving all significant impurities from styrene and from t
20、he internalstandard. The choice of column is based on resolution requirements. Any column may be used that is capable of resolving allsignificant impurities from the major component. The column and conditions described in Table 2 have been used successfully andshall be used as a referee in cases of
21、dispute.7.2.1 “Total non-aromatics” are defined as all components eluting before o-xylene, excluding benzene, toluene, ethylbenzene,p-xylene, m-xylene, and cumene. The internal standard used for calibration is also excluded. Generally, non-aromatics are summedand reported as a group. In certain case
22、s, one or more individual non-aromatic components, such as 1,4-dioxane, may be reportedseparately. In those cases, the grouping would not include the separately reported component(s), and the remaining non-aromaticswould be reported as “Nonaromatics other than (component(s).”7.2.2 “Total C9plus arom
23、atics” are defined as cumene, plus all components eluting after o-xylene. Generally, C9plusaromatics are summed and reported as a group. In certain cases, one or more individual C9plus aromatic components, such ascumene or p-diethylbenzene, may be reported separately. In those cases, the grouping wo
24、uld not include the separately reportedTABLE 1 Impurities Known or Suggested to be Present inCommercial StyreneEthylbenzeneEthylbenzeneo-xyleneo-xylenem-xylenep-xyleneIsopropylbenzenen-propylbenzenem-ethyltoluenep-ethyltoluene-methylstyrenem-vinyltoluenep-vinyltoluenePhenylacetyleneTABLE 2 Recommend
25、ed Operating ConditionsCarrier 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 150Colum
26、n 60 m 0.32 mm ID 0.5 mbonded polyethylene glycol-fused silica capillaryColumn temperature, C 110Chart speed, cm/min 1Sample size, L 0.6D5135 162component(s) and the remaining C9plus aromatics would be reported as “C9plus aromatics other than (component(s).” Veryheavy non-aromatics may also elute in
27、 this region, but they are not common in materials within the scope of Committee D16, andare not considered in the definition.7.3 RecorderElectronic integration, with tangent capabilities is recommended.7.4 100-mL Volumetric Flask.7.5 Microsyringes, assorted volumes.8. Reagents and Materials8.1 Puri
28、ty of ReagentReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society,4 wheresuch specifications are available.8.2 Carrier Gas, makeup a
29、nd detector gases 99.999 % purity. Oxygen in carrier gas less than 1 ppm, less than 0.5 ppm ispreferred. Purify carrier, makeup and detector gases to remove oxygen, water, and hydrocarbons.8.3 Air, purify to remove hydrocarbons and water. Air should contain less than 0.1 ppm THC.8.4 n-Heptane, 99.0
30、% minimum purity, or other internal standard, 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 than 99.7 %.8.6 Pure Compounds, for calibration, shall be those compounds that are typically pres
31、ent in commercial styrene. These shouldbe at least 99 % pure as they are to be used for determining response factors.9. Hazards9.1 Consult current OSHA regulations, suppliers Material suppliersSafety Data Sheets, and local regulations for all materialsused in this procedure.10. Sampling10.1 Sample t
32、he material in accordance with Practice D3437.11. Preparation of Apparatus11.1 Follow manufacturersmanufacturers instructions for mounting and conditioning the column into the chromatograph andadjusting the instrument conditions described in Table 2, allowing sufficient time for the equipment to rea
33、ch equilibrium. SeePractices E355 and E1510 for additional information on gas chromatographic practices and terminology.12. Calibration12.1 Prepare a calibration mixture containing approximately 99.5 weight % styrene and the expected significant impurities attheir expected concentration (see Practic
34、e D4307). Weigh all components to the accuracy required to calculate the concentrationof each to the nearest 0.001 %.12.2 With a microsyringe, add 50 L of internal standard to a 100mL volumetric flask about three-fourths full of calibrationmixture. Mix well. Add calibration mixture to mark and again
35、 mix well. If n-heptane is used as the internal standard, using adensity 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 the calibration blend with and without n-heptane to determine theconcentratio
36、n of existing impurities and interfering compounds with internal standard. If impurities in the styrene emerge with thechosen internal standard, an alternate internal standard must be used.12.4 Inject an appropriate amount of sample into the chromatograph and obtain a chromatogram.12.5 Measure the a
37、reas of all peaks, including the internal standard, except the styrene peak.12.6 Calculate the response factors for each impurity relative to the internal standard as follows:RFi5 CiCs!S AiAsi2 AbAsbD (1)4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washin
38、gton, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D5135 163
39、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 making calibration mixture,Ab = area of impurity in styrene used to make calibrati
40、on mixture,Cs = weight percent internal standard in calibration mixture, andCi = weight percent impurity in calibration mixture.13. Procedure13.1 Establish stable instrument operation at the prescribed or selected operating conditions. Reference should be made toinstructions provided by the manufact
41、urer of the chromatograph.13.2 Prepare sample as described in 12.2.13.3 Inject appropriate amount of sample into the chromatograph and obtain the chromatogram. A typical chromatogram isshown in Fig. 1.14. Calculation14.1 Measure the areas of all peaks, including the internal standard, except the sty
42、rene peak.14.2 Calculate the weight percent of the individual impurities, 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 internal standard, andCs = concentration of internal standard, in weight percent.1
43、4.3 Calculate the styrene content by subtracting the sum of the impurities from 100.00. Styrene weight per-cent = 100.00 (sum of impurities).FIG. 1 Typical Chromatogram (see Table 2)D5135 16415. Report15.1 Report the concentration of impurities to the nearest 0.001 % and the styrene content to the n
44、earest 0.01 %.16. Precision and Bias516.1 PrecisionThe following criteria should be used to judge the acceptability (95 % probability level) of results obtained bythis test method (see Practice E691). The criteria were derived from a round robin among six laboratories. The data were run ontwo days u
45、sing different operators.16.1.1 The criteria presented in Table 3 and Table 4 were derived from a Interlaboratory Study (ILS) among six laboratories.The data were run on two days using different operators.16.1.2 The criteria and precision data presented in Table 5 were derived from a commercial Prof
46、iciency Testing schemeperformed during the years 1997 through 2014 (no formal PT report available, however data are available to ASTM).16.2 Intermediate Precision (formerly called Repeatability)Results in the same laboratory should not be considered suspectunless they differ by more than the normal
47、amount shown in Table 3 and Table 4.16.3 ReproducibilityThe results by each of two laboratories should not be considered suspect unless they differ by more thanthe amount shown in Table 3 and, Table 4 and Table 45.16.4 BiasBias of this test method for the analysis of styrene has not been determined
48、because no acceptable reference materialis available.17. Quality Guidelines17.1 Laboratories shall have a quality control system in place.17.1.1 Confirm the performance of the test instrument or test method by analyzing a quality control sample following theguidelines of standard statistical quality
49、 control practices.17.1.2 Aquality control sample is a stable material isolated from the production process and representative of the sample beinganalyzed.17.1.3 When QA/QC protocols are already established in the testing facility, these protocols are acceptable when they confirmthe validity of test results.17.1.4 When there are no QA/QC protocols established in the testing facility, use the guidelines described in Guide D6809 orsimilar statistical quality control practices.18. Keywords18.1 analysis by gas chromatography; impurities in
