1、Designation: D5194 11aD5194 13Standard 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 revisi
2、on. 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 andcyclohexa
3、ne.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 determinin
4、g 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 and health practices and determine the applicability of regulatorylimitations prior to use. For a specific ha
6、zard statement, see Section 7.2. Referenced Documents2.1 ASTM Standards:2D891 Test Methods for Specific Gravity, Apparent, of Liquid Industrial ChemicalsD1193 Specification for Reagent WaterD1555M Test Method for Calculation of Volume and Weight of Industrial Aromatic Hydrocarbons and Cyclohexane Me
7、tricD3437 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 Density MeterD6809 Guide for Quality Control and Quality Assurance Proce
8、dures for Aromatic Hydrocarbons and Related MaterialsE29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications2.2 Other Documents:3OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.12003. Summary of Test Method3.1 Aknown amount of hydrocarbon sample is
9、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 acidified, washed, and concentrated.Acetone is added and the solu
10、tion is titrated with silver nitratesolution.4. Significance and Use4.1 Organic and inorganic chlorine compounds can have a deleterious effect on equipment and reactions in processes involvingaromatic hydrocarbons.1 This test method is under the jurisdiction of ASTM Committee D16 on Aromatic Hydroca
11、rbons and Related Chemicals and is the direct responsibility of SubcommitteeD16.04 on Instrumental Analysis.Current edition approved June 1, 2011July 1, 2013. Published July 2011July 2013. Originally approved in 1991. Last previous edition approved in 2011 asD5194 11.D5194 11a. DOI: 10.1520/D5194-11
12、A.10.1520/D5194-13.2 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 standards Document Summary page on the ASTM website.3 Available from U.S. Government Printing
13、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 the previous version. Becausei
14、t 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 Summary of Changes section appears a
15、t the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 Maximum chloride levels are often specified for process streams and for aromatic hydrocarbon products.5. Apparatus5.1 Titrator, potentiometric, recording, +
16、 2000 mV range, 1 mV resolution with dispenser having a volume readout of 0.00 to9.99 mL or 0.00 to 99.99 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. Unl
17、ess otherwise indicated, it is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where suchspecifications are available.4 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently hig
18、h purityto permit its use without lessening the accuracy of the determination.6.2 Purity of WaterUnless 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,
19、 residue free.6.6 Isobutanol, 99.9 % minimum purity.6.7 Isooctane.6.8 Nitric Acid, concentrated.6.9 Nitric 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
20、Silver Nitrate, 99.99 % minimum purity.6.14 Silver Nitrate Solution, 0.01 N, standardized to 0.1 %.NOTE 1This solution may be obtained as follows:(1)(1) Purchase from a laboratory supply company, (2)(2) Weigh to four places, 1.680 to 1.720 g silver nitrate, transfer quantitatively into a 1000-mLvolu
21、metric flask, make to mark with water, and mix well.Normality of solution5Weight AgNO3169.9or (3)(3) Dissolve 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 thenearest 0.1 mg into a 250-mL electrolytic beaker, add 100 mL of w
22、ater and a stirring bar. While stirring, titrate with the silver nitrate solution.Normality of AgNO3 solution5 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 t
23、o give the normality of final AgNO3 solution.6.15 Sodium Biphenyl ReagentThe reagent is normally packed in 15-mLindividual vials that contain 0.2 to 0.4 g of activesodium each.6.16 Toluene, 99.9 % minimum purity.7. Hazards7.1 Amaterial, such as styrene, which is polymerized by sodium biphenyl can ca
24、use a violent reaction and should never be usedas the sample.7.2 Consult current OSHA regulations and suppliers Material Safety Data Sheets, and local regulations for all materials usedin this test method.4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washi
25、ngton, 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.D5194 13
26、28. Sampling8.1 Refer to Practice D3437 for proper sampling and handling of liquid hydrocarbons analyzed 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
27、potassium chloride solution until the electrode tip turns light gray.9.3 Rinse well with water and attach 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 Extrem
28、e care must be used to prevent contamination and all glassware should be exclusively reserved for this 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 t
29、he liquid sample that corresponds tothe estimated chloride content as prescribed in Table 1.NOTE 2It is 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. Dens
30、ities of unknowns may be determined by using Test Methods D891, D3505 or D4052.NOTE 3Alternately, place 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 w
31、eight of the analytical specimen.10.3 Add the contents of one vial of sodium biphenyl reagent, stopper 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
32、at a time) until the blue green color persists.NOTE 4The sodium biphenyl reagent has a limited shelf life, 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
33、 room temperature for several days justprior to use to dissolve any sodium biphenyl that may have precipitated 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. Stoppe
34、r the funnel again and rock it gently for 1 min, venting the pressurefrequently through the stopcock.10.5 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 contain
35、ing 50 mL isooctane and shake well. Drain theaqueous phase into a 250-mL electrolytic beaker.10.7 Make 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
36、, allow the phases to separate and drain theaqueous phase into the beaker containing the first water extract.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
37、 to about 30 mL on a hot plate.10.9.1 Warning: Loss of chloride may result if the solution is boiled or 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
38、titrant used to reach the end point.10.11 Determine a blank for each group of samples, using all the reagents 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 Chl
39、oride11.1 Follow the procedure in Section 10 but without adding the sodium biphenyl reagent to either the sample or the blank.12. 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
40、chloride to give the organic chloride.TABLE 1 Specimen SizeEstimated chloride, mg/kg Specimen volume, mL0 to 5 1005 to 25 50D5194 13313. 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
41、= volume of titrant for blank, mL,N = normality of silver nitrate solution,V = volume of sample, mL, andD = density or relative density of sample.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, a
42、ndD = 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.where:T = total chloride, mg/kg andI = inorganic chloride, mg/kg.13.3 Report chloride to the nearest 0.1 mg/kg.14. Pr
43、ecision and Bias14.1 Precision:14.1.1 The data for determining the 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
44、 used to judge the acceptability (95 % probability) of results obtained 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 t
45、he same laboratory should not be consideredsuspect unless they differ 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 r
46、eferee method is available to determine the true value.15. Quality Guidelines15.1 Laboratories shall have a quality control system in place.TABLE 2 Densities of HydrocarbonsComponent Density in vacuoat 20Cg/ccBenzene 0.87908Cyclohexane 0.77849Ethylbenzene 0.86685Isopropylbenzene (cumene) 0.86160Styr
47、ene 0.90586Toluene 0.86686m-Xylene 0.86408o-Xylene 0.87968p-Xylene 0.86076D5194 13415.1.1 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
48、stable material isolated from the production process and representative 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 estab
49、lished 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 the last issue(D5194 - 11D5194)-11a) that may impact the use of this standard. (Approved JuneJuly 1, 2011.)2013.)(1) Table 2 was modified to include units for density and the values were updated to be consistent with Test Method UpdatedSection
