ASTM D5194-2011a Standard Test Method for Trace Chloride in Liquid Aromatic Hydrocarbons《液体芳香烃中微量氯化物的标准试验方法》.pdf

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1、Designation: D5194 11aStandard 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 revision. A nu

2、mber 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 totalchloride (organic and inorganic) in liquid aromatic hydrocar-bons and cyclohexane.1.2

3、The test method is applicable to samples with chlorideconcentrations of 1 to 25 mg/kg.1.3 Bromides and iodides, if present, will be calculated aschlorides.1.4 Materials, such as styrene, that are polymerized bysodium biphenyl reagent cannot be analyzed by this testmethod.1.5 In determining the confo

4、rmance of the test results usingthis method to applicable specifications, results shall berounded off in accordance with the rounding-off method ofPractice E29.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 This standar

5、d does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For a specifichazard statement

6、, see Section 7.2. Referenced Documents2.1 ASTM Standards:2D891 Test Methods for Specific Gravity, Apparent, ofLiquid Industrial ChemicalsD1193 Specification for Reagent WaterD1555M Test Method for Calculation of Volume andWeight of Industrial Aromatic Hydrocarbons and Cyclo-hexane MetricD3437 Pract

7、ice for Sampling and Handling Liquid CyclicProductsD3505 Test Method for Density or Relative Density of PureLiquid ChemicalsD4052 Test Method for Density, Relative Density, and APIGravity of Liquids by Digital Density MeterD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic

8、Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 Other Documents:3OSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.12003. Summary of Test Method3.1 A known amount of hydrocarbon sample is transferredinto a s

9、eparatory funnel containing toluene. Sodium biphenylreagent is added to convert organic halogens into inorganichalides. The excess reagent is decomposed with water and thephases are separated. The aqueous phase is acidified, washed,and concentrated. Acetone is added and the solution is titratedwith

10、silver nitrate solution.4. Significance and Use4.1 Organic and inorganic chlorine compounds can have adeleterious effect on equipment and reactions in processesinvolving aromatic hydrocarbons.4.2 Maximum chloride levels are often specified for processstreams and for aromatic hydrocarbon products.5.

11、Apparatus5.1 Titrator, potentiometric, recording, + 2000 mV range, 1mV resolution with dispenser having a volume readout of 0.00to 9.99 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 ReagentsReage

12、nt grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society, where1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarb

13、ons and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved June 1, 2011. Published July 2011. Originally approvedin 1991. Last previous edition approved in 2011 as D5194 11. DOI: 10.1520/D5194-11A.2For referenced ASTM standards,

14、 visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. 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 S

15、t., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.such specifications are available.4Other grades

16、may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Types II or III of

17、 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 Nitric Acid, 5-M. Dilute 160 mL concentrated nitric acidto 500 mL with water.6.10 Potassium Chloride, primary standard

18、.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 %.NOTE 1This solution may be obtained as follows:(1) Purchase from a laboratory supply company, (2) Weigh to fourplaces, 1

19、.680 to 1.720 g silver nitrate, transfer quantitatively into a1000-mL volumetric flask, make to mark with water, and mix well.Normality of solution 5Weight AgNO3169.9or (3) Dissolve 8.5 g silver nitrate in 500 mL water to give a 0.1 Nsolution. Weigh 0.09 to 0.10 g of dried (105C) potassium chloride

20、to thenearest 0.1 mg into a 250-mLelectrolytic beaker, add 100 mLof water anda stirring bar. While stirring, titrate with the silver nitrate solution.Normality of AgNO3solution 5Weight KCl0.0746 3 mL AgNO3Pipet 50.00 mL of the solution into a 500-mL volumetric flask, dilute tomark with water, and mi

21、x well. Divide the calculated normality of the 0.1N solution by 10 to give the normality of final AgNO3solution.6.15 Sodium Biphenyl ReagentThe reagent is packed in15-mL vials that contain 0.2 to 0.4 g of active sodium each.6.16 Toluene, 99.9 % minimum purity.7. Hazards7.1 A material, such as styren

22、e, which is polymerized bysodium biphenyl can cause a violent reaction and should neverbe used as the sample.7.2 Consult current OSHA regulations and suppliers Mate-rial Safety Data Sheets, and local regulations for all materialsused in this test method.8. Sampling8.1 Refer to Practice D3437 for pro

23、per sampling and han-dling of liquid hydrocarbons analyzed by this test method.9. Electrode Preparation9.1 Clean the surface of the silver electrode with milddetergent and scouring powder, and rinse with water.9.2 Immerse the electrode in the saturated potassium chlo-ride solution until the electrod

24、e tip turns light gray.9.3 Rinse well with water and attach to the titrimeter.9.4 Repeat the electrode preparation when the silver chlo-ride 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 contaminationa

25、nd all glassware should be exclusively reserved for thisanalysis. Just prior to use, the glassware should be rinsed withwater followed by acetone and then air dried.10.2 Place 50 mL of toluene into a 250-mL separatoryfunnel and pipet in the amount of the liquid sample thatcorresponds to the estimate

26、d chloride content as prescribed inTable 1.NOTE 2It is generally more convenient to measure the liquid samplesby volume and then convert to mass using density or relative density.Table 2 lists the relative densities of several pure hydrocarbons. Densitiesof unknowns may be determined by using Test M

27、ethods D891, D3505 orD4052.NOTE 3Alternately, place the sample into a 125-mL bottle and weigh.From the contents of this bottle add the appropriate amount of the sampleto the toluene in the separatory funnel. Reweigh the bottle, and determinethe weight of the analytical specimen.10.3 Add the contents

28、 of one vial of sodium biphenylreagent, stopper the separatory funnel, and gently swirl to mixthoroughly, venting the funnel from time to time. If theresulting solution or suspension is not blue-green, add moresodium biphenyl reagent (one vial at a time) until the bluegreen color persists.NOTE 4The

29、sodium biphenyl reagent has a limited shelf life, given assix months by the manufacturer. This can be extended, in most cases, toapproximately one year by keeping the reagent under refrigeration. If thisis done, the reagent should be kept at room temperature for several daysjust prior to use to diss

30、olve any sodium biphenyl that may haveprecipitated upon cooling.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals,

31、 BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Specimen SizeEstimated chloride, mg/kg Specimen volume, mL0to5 1005to25 50TABLE 2 Densities of HydrocarbonsComponent Density in vacuoat 20Cg/ccBe

32、nzene 0.87908Cyclohexane 0.77849Ethylbenzene 0.86685Isopropylbenzene (cumene) 0.86160Styrene 0.90586Toluene 0.86686m-Xylene 0.86408o-Xylene 0.87968p-Xylene 0.86076D5194 11a210.4 Allow the mixture to stand for approximately 10 min.Slowly add 20 mL water and swirl gently with the funnelunstoppered unt

33、il the blue-green color changes to white.Stopper the funnel again and rock it gently for 1 min, ventingthe pressure frequently through the stopcock.10.5 Add 10 mL 5 N nitric acid, and then 5 mL isobutanol.Shake gently, releasing the pressure frequently through thestopcock.10.6 Drain the aqueous phas

34、e into another 250-mL separa-tory funnel containing 50 mL isooctane and shake well. Drainthe aqueous phase into a 250-mL electrolytic beaker.10.7 Make a second extraction of the specimen solutionwith 20 mL water acidified with 6 drops of 5-M nitric acid anddrain the aqueous phase into the separatory

35、 funnel containingthe isooctane. After shaking, allow the phases to separate anddrain the aqueous phase into the beaker containing the firstwater extract.10.8 Test the aqueous solution with Congo red paper, and ifit does not test acidic, add 5-N nitric acid dropwise with stirringuntil the test paper

36、 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 solutionis boiled or evaporated below 25 mL.10.10 Allow the solution to cool, and add 100 mL ofacetone. Titrate the solution potentiometrically with standard0.01 N silver nit

37、rate solution and determine the volume oftitrant used to reach the end point.10.11 Determine a blank for each group of samples, usingall the reagents including as many vials of sodium biphenyl aswere used in the analysis of a sample. Follow all the operationsof the analysis, except omit the specimen

38、 itself.11. Procedure for Inorganic Chloride11.1 Follow the procedure in Section 10 but without addingthe 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 todetermine the total and inorganic chlorides.

39、Subtract theinorganic from the total chloride to give the organic chloride.13. Calculation13.1 Calculate either the total or inorganic chloride asfollows:Chloride, mg/kg 535,500 A 2 B!VDN (1)where:A = volume of titrant for aqueous phase, mL,B = volume of titrant for blank, mL,N = normality of silver

40、 nitrate solution,V = volume of sample, mL, andD = density or relative density of sample.13.2 Calculate organic chloride as follows:Organic chloride, mg/kg 5 T 2 I (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 Bias

41、14.1 Precision:14.1.1 The data for determining the precision of this testmethod are based on the analyses of toluene, ethylbenzene, andp-xylene that had been spiked with organic chloride com-pounds to the 1, 5, and 25 mg/kg chloride levels each.14.1.2 The following criteria should be used to judge t

42、heacceptability (95 % probability) of results obtained by this testmethod. The criteria were derived from a round robin betweenthree laboratories. Each sample was run on two different daysin each laboratory.14.1.2.1 Intermediate Precision (formerly calledRepeatability)Results in the same laboratory

43、should not beconsidered suspect unless they differ by more than 0.5 mg/kg.14.1.2.2 ReproducibilityResults from each of two labora-tories should not be considered suspect unless they differ bymore than 0.9 mg/kg.14.2 BiasThe bias of this test method cannot be deter-mined because no referee method is

44、available to determine thetrue value.15. Quality Guidelines15.1 Laboratories shall have a quality control system inplace.15.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality control practices

45、.15.1.2 A quality control sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.15.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test results.15.1.4 Whe

46、n there are no QA/QC protocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical quality control practices.16. Keywords16.1 aromatic hydrocarbons; chloride; cyclohexane; ethyl-benzene; p-xylene; tolueneD5194 11a3SUMMARY OF CHANGESCommittee D16 has

47、identified the location of selected changes to this standard since the last issue (D5194 - 11)that may impact the use of this standard. (Approved June 1, 2011.)(1) Table 2 was modified to include units for density and thevalues were updated to be consistent with Test MethodD1555M.Committee D16 has i

48、dentified the location of selected changes to this standard since the last issue (D5194 - 06)that may impact the use of this standard. (Approved February 1, 2011.)(1) Section 15 (Quality Guidelines) was revised to current D16Editorial Guidelines.ASTM International takes no position respecting the va

49、lidity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addresse