1、Designation: D5194 13D5194 18Standard Test Method forTrace Chloride in Liquid Aromatic Hydrocarbons1This standard is issued under the fixed designation D5194; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. 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 total chloride (organic and inorganic) in liquid aromatic hydrocarbons andcyclohexan
3、e.1.2 The test method is applicable to samples with chloride concentrations of 1 to 25 mg/kg.1.3 Bromides and iodides, if present, will be calculated as chlorides.1.4 Materials, such as styrene, that are polymerized by sodium biphenyl reagent cannot be analyzed by this test method.1.5 In determining
4、 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 E29.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.
5、7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations pri
6、or to use. For a specific hazard statement, see Section 7.1.8 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issu
7、edby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D891 Test Methods for Specific Gravity, Apparent, of Liquid Industrial Chemicals (Withdrawn 2018)3D1193 Specification for Reagent WaterD1555M Test Method for Calculation of Volume
8、 and Weight of Industrial Aromatic Hydrocarbons and Cyclohexane MetricD3437 Practice for Sampling and Handling Liquid Cyclic ProductsD3505 Test Method for Density or Relative Density of Pure Liquid ChemicalsD4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Densit
9、y MeterD6809 Guide 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 Specifications2.2 Other Documents:4OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.12003.
10、 Summary of Test Method3.1 Aknown amount of hydrocarbon sample is transferred into a separatory funnel containing toluene. Sodium biphenyl reagentis added to convert organic halogens into inorganic halides. The excess reagent is decomposed with water and the phases areseparated. The aqueous phase is
11、 acidified, washed, and concentrated.Acetone is added and the solution is titrated with silver nitratesolution.1 This test method is under the jurisdiction of ASTM Committee D16 on Aromatic Hydrocarbons Aromatic, Industrial, Specialty and Related Chemicals and is the directresponsibility of Subcommi
12、ttee D16.04 on Instrumental Analysis.Current edition approved July 1, 2013Jan. 1, 2018. Published July 2013January 2018. Originally approved in 1991. Last previous edition approved in 20112013 asD5194 11a.D5194 13. DOI: 10.1520/D5194-13.10.1520/D5194-18.2 For referencedASTM standards, visit theASTM
13、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.3 The last approved version of this historical standard is referenced on www.astm.org.4 Available
14、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 been made to
15、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 document.*A Summar
16、y 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 States14. Significance and Use4.1 Organic and inorganic chlorine compounds can have a deleterious effect on equipment and reactions in pr
17、ocesses involvingaromatic hydrocarbons.4.2 Maximum chloride levels are often specified for process streams and for aromatic hydrocarbon products.5. Apparatus5.1 Titrator, potentiometric, recording, + 2000 mV range, 1 mV resolution with dispenser having a volume readout of 0.00 to9.99 mL or 0.00 to 9
18、9.99 mL and 0.01 % resolution.5.2 Electrode, glass, reference.5.3 Electrode, silver, billet type.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committ
19、ee on Analytical Reagents of the American Chemical Society, where suchspecifications are available.5 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of the determination.6.2 Purity of WaterUnle
20、ss otherwise indicated, references to water shall be understood to mean reagent water as defined byTypes II or III of Specification D1193.6.3 Acetone, 99.9 % purity.6.4 Congo Red Paper.6.5 Detergent, residue free.6.6 Isobutanol, 99.9 % minimum purity.6.7 Isooctane.6.8 Nitric Acid, concentrated.6.9 N
21、itric Acid, 5-M. Dilute 160 mL concentrated nitric acid to 500 mL with water.6.10 Potassium Chloride, primary standard.6.11 Potassium Chloride Solution, saturated.6.12 Scouring Powder, cleanser.6.13 Silver Nitrate, 99.99 % minimum purity.6.14 Silver Nitrate Solution, 0.01 N, standardized to 0.1 %.NO
22、TE 1This solution may be obtained as follows:(1) Purchase from a laboratory supply company, (2) Weigh to four places, 1.680 to 1.720 g silver nitrate, transfer quantitatively into a 1000-mLvolumetric flask, make to mark with water, and mix well.Normality of solution5Weight AgNO3169.9or (3) Dissolve
23、8.5 g silver nitrate in 500 mL water to give a 0.1 N solution. Weigh 0.09 to 0.10 g of dried (105C) potassium chloride to the near-est 0.1 mg into a 250-mL electrolytic beaker, add 100 mL of water and a stirring bar. While stirring, titrate with the silver nitrate solution.Normality of AgNO3 solutio
24、n5 Weight KCl0.07463mL AgNO3Pipet 50.00 mL of the solution into a 500-mL volumetric flask, dilute to mark with water, and mix well. Divide the calculated normality of the 0.1N solution by 10 to give the normality of final AgNO3 solution.6.15 Sodium Biphenyl ReagentThe reagent is normally packed in i
25、ndividual vials that contain 0.2 to 0.4 g of active sodiumeach.6.16 Toluene, 99.9 % minimum purity.7. Hazards7.1 Amaterial, such as styrene, which is polymerized by sodium biphenyl can cause a violent reaction and should never be usedas the sample.5 Reagent Chemicals, American Chemical Society Speci
26、fications, American Chemical Society, Washington, 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 Conv
27、ention, Inc. (USPC), Rockville, MD.D5194 1827.2 Consult current OSHA regulations and suppliers Material suppliers Safety Data Sheets, and local regulations for allmaterials used in this test method.8. Sampling8.1 Refer to Practice D3437 for proper sampling and handling of liquid hydrocarbons analyze
28、d by this test method.9. Electrode Preparation9.1 Clean the surface of the silver electrode with mild detergent and scouring powder, and rinse with water.9.2 Immerse the electrode in the saturated potassium chloride solution until the electrode tip turns light gray.9.3 Rinse well with water and atta
29、ch to the titrimeter.9.4 Repeat the electrode preparation when the silver chloride film begins to peel from the surface, or if the film becomesdiscolored.10. Procedure for Total Chloride10.1 Extreme care must be used to prevent contamination and all glassware should be exclusively reserved for this
30、analysis. Justprior to use, the glassware should be rinsed with water followed by acetone and then air dried.10.2 Place 50 mL of toluene into a 250-mL separatory funnel and pipet in the amount of the liquid sample that corresponds tothe estimated chloride content as prescribed in Table 1.NOTE 2It is
31、 generally more convenient to measure the liquid samples by volume and then convert to mass using density or relative density. Table2 lists the relative densities of several pure hydrocarbons. Densities of unknowns may be determined by using Test Methods D891, D3505 or D4052.NOTE 3Alternately, place
32、 the sample into a 125-mL bottle and weigh. From the contents of this bottle add the appropriate amount of the sample tothe toluene in the separatory funnel. Reweigh the bottle, and determine the weight of the analytical specimen.10.3 Add the contents of one vial of sodium biphenyl reagent, stopper
33、the separatory funnel, and gently swirl to mix thoroughly,venting the funnel from time to time. If the resulting solution or suspension is not blue-green, add more sodium biphenyl reagent(one vial at a time) until the blue green color persists.NOTE 4The sodium biphenyl reagent has a limited shelf li
34、fe, given as six months by the manufacturer. This can be extended, in most cases, toapproximately one year by keeping the reagent under refrigeration. If this is done, the reagent should be kept at room temperature for several days justprior to use to dissolve any sodium biphenyl that may have preci
35、pitated upon cooling.10.4 Allow the mixture to stand for approximately 10 min. Slowly add 20 mL water and swirl gently with the funnelunstoppered until the blue-green color changes to white. Stopper the funnel again and rock it gently for 1 min, venting the pressurefrequently through the stopcock.10
36、.5 Add 10 mL5 N nitric acid, and then 5 mLisobutanol. Shake gently, releasing the pressure frequently through the stopcock.10.6 Drain the aqueous phase into another 250-mL separatory funnel containing 50 mL isooctane and shake well. Drain theaqueous phase into a 250-mL electrolytic beaker.10.7 Make
37、a second extraction of the specimen solution with 20 mL water acidified with 6 drops of 5-M nitric acid and drainthe aqueous phase into the separatory funnel containing the isooctane. After shaking, allow the phases to separate and drain theaqueous phase into the beaker containing the first water ex
38、tract.10.8 Test the aqueous solution with Congo red paper, and if it does not test acidic, add 5-N nitric acid dropwise with stirringuntil the test paper turns dark blue.10.9 Evaporate the solution to about 30 mL on a hot plate.10.9.1 Warning: Loss of chloride may result if the solution is boiled or
39、 evaporated below 25 mL.10.10 Allow the solution to cool, and add 100 mL of acetone. Titrate the solution potentiometrically with standard 0.01 N silvernitrate solution and determine the volume of titrant used to reach the end point.10.11 Determine a blank for each group of samples, using all the re
40、agents including as many vials of sodium biphenyl as wereused in the analysis of a sample. Follow all the operations of the analysis, except omit the specimen itself.11. Procedure for Inorganic Chloride11.1 Follow the procedure in Section 10 but without adding the sodium biphenyl reagent to either t
41、he sample or the blank.TABLE 1 Specimen SizeEstimated chloride, mg/kg Specimen volume, mL0 to 5 1005 to 25 50D5194 18312. Procedure for Organic Chloride12.1 Follow the procedures given in Sections 10 and 11 to determine the total and inorganic chlorides. Subtract the inorganicfrom the total chloride
42、 to give the organic chloride.13. Calculation13.1 Calculate either the total or inorganic chloride as follows:Chloride,mg/kg535,500 A 2B!VD N (1)where:A = volume of titrant for aqueous phase, mL,B = volume of titrant for blank, mL,N = normality of silver nitrate solution,V = volume of sample, mL, an
43、dD = density or relative density of sample.13.2 Calculate organic chloride as follows:Organic chloride,mg/kg5T 2I (2)where:T = total chloride, mg/kg andI = inorganic chloride, mg/kg.13.3 Report chloride to the nearest 0.1 mg/kg.14. Precision and Bias14.1 Precision:14.1.1 The data for determining the
44、 precision of this test method are based on the analyses of toluene, ethylbenzene, andp-xylene that had been spiked with organic chloride compounds to the 1, 5, and 25 mg/kg chloride levels each.14.1.2 The following criteria should be used to judge the acceptability (95 % probability) of results obt
45、ained by this test method.The criteria were derived from a round robin between three laboratories. Each sample was run on two different days in eachlaboratory.14.1.2.1 Intermediate Precision (formerly called Repeatability)Results in the same laboratory should not be consideredsuspect unless they dif
46、fer by more than 0.5 mg/kg.14.1.2.2 ReproducibilityResults from each of two laboratories should not be considered suspect unless they differ by morethan 0.9 mg/kg.14.2 BiasThe bias of this test method cannot be determined because no referee method is available to determine the true value.15. Quality
47、 Guidelines15.1 Laboratories shall have a quality control system in place.TABLE 2 Densities of HydrocarbonsComponentDensity in vacuoat 20Cg/ccBenzene 0.87908Benzene 0.87908Cyclohexane0.77849Ethylbenzene0.86685Isopropylbenzene (cumene)0.86160Styrene 0.90586Toluene0.86686m-Xylene0.86408o-Xylene0.87968
48、p-Xylene0.86076D5194 18415.1.1 Confirm the performance of the test instrument or test method by analyzing a quality control sample following theguidelines of standard statistical quality control practices.15.1.2 Aquality control sample is a stable material isolated from the production process and re
49、presentative of the sample beinganalyzed.15.1.3 When QA/QC protocols are already established in the testing facility, these protocols are acceptable when they confirmthe validity of test results.15.1.4 When there are no QA/QC protocols established in the testing facility, use the guidelines described in Guide D6809 orsimilar statistical quality control practices.16. Keywords16.1 aromatic hydrocarbons; chloride; cyclohexane; ethylbenzene; p-xylene; tolueneSUMMARY OF CHANGESCommittee D16 has identified the location of selected changes to this standard since
