1、Designation: D 5194 06Standard Test Method forTrace Chloride in Liquid Aromatic Hydrocarbons1This standard is issued under the fixed designation D 5194; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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.
3、2 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 con
4、formance 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 stand
5、ard 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 stateme
6、nt, see Section 7.2. Referenced Documents2.1 ASTM Standards:2D 891 Test Methods for Specific Gravity, Apparent, ofLiquid Industrial ChemicalsD 1193 Specification for Reagent WaterD 3437 Practice for Sampling and Handling Liquid CyclicProductsD 3505 Test Method for Density or Relative Density ofPure
7、Liquid ChemicalsD 4052 Test Method for Density and Relative Density ofLiquids by Digital Density MeterD 6809 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 S
8、pecifications2.2 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 separatory funnel containing toluene. Sodium biphenylreagent is added to convert organic halogens into inorganichalides.
9、 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 silver nitrate solution.4. Significance and Use4.1 Organic and inorganic chlorine compounds can have adeleterious effec
10、t on equipment and reactions in processesinvolving aromatic hydrocarbons.4.2 Maximum chloride levels are often specified for processstreams and for aromatic hydrocarbon products.5. Apparatus5.1 Titrator, potentiometric, recording, + 2000 mV range, 1mV resolution with dispenser having a volume readou
11、t 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 ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to th
12、e specifications of the Committee on1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved March 1, 2006. Published March 2006. Originally
13、approved in 1991. Last previous edition approved in 2004 as D 5194 04.2For referenced ASTM standards, 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
14、 website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.1*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
15、 19428-2959, United States.Analytical Reagents of the American Chemical Society, wheresuch specifications are available.4Other grades 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 P
16、urity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Types II or III of Specification D 1193.6.3 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,
17、concentrated.6.9 Nitric Acid, 5-M. Dilute 160 mL concentrated nitric acidto 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, standar
18、dized to 0.1 %.NOTE 1This solution may be obtained as follows:(1) Purchase from a laboratory supply company, (2) Weigh to fourplaces, 1.680 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.
19、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 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 Ag
20、NO3solution 5Weight KCl0.0746 3 mL AgNO3Pipet 50.00 mL of the solution into a 500-mL volumetric flask, dilute tomark with water, and mix 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 in1
21、5-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 styrene, 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-
22、rial Safety Data Sheets, and local regulations for all materialsused in this test method.8. Sampling8.1 Refer to Practice D 3437 for proper sampling andhandling of liquid hydrocarbons analyzed by this test method.9. Electrode Preparation9.1 Clean the surface of the silver electrode with milddetergen
23、t and scouring powder, and rinse with water.9.2 Immerse the electrode in the saturated potassium chlo-ride 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 chlo-ride film begins to peel from
24、the surface, or if the film becomesdiscolored.10. Procedure for Total Chloride10.1 Extreme care must be used to prevent contaminationand 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.1
25、0.2 Place 50 mL of toluene into a 250-mL separatoryfunnel and pipet in the amount of the liquid sample thatcorresponds to the estimated 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 rela
26、tive density.Table 2 lists the relative densities of several pure hydrocarbons. Densitiesof unknowns may be determined by using Test Methods D 891, D 3505 orD 4052.NOTE 3Alternately, place the sample into a 125-mL bottle and weigh.From the contents of this bottle add the appropriate amount of the sa
27、mpleto the toluene in the separatory funnel. Reweigh the bottle, and determinethe weight of the analytical specimen.10.3 Add the contents of one vial of sodium biphenylreagent, stopper the separatory funnel, and gently swirl to mixthoroughly, venting the funnel from time to time. If theresulting sol
28、ution or suspension is not blue-green, add moresodium biphenyl reagent (one vial at a time) until the bluegreen color persists.NOTE 4The 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
29、the reagent under refrigeration. If thisis done, the reagent should be kept at room temperature for several daysjust prior to use to dissolve any sodium biphenyl that may haveprecipitated upon cooling.10.4 Allow the mixture to stand for approximately 10 min.Slowly add 20 mL water and swirl gently wi
30、th the funnelunstoppered until 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
31、.10.6 Drain the aqueous phase 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 and4Reagent Chemic
32、als, 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, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National
33、Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Specimen SizeEstimated chloride, mg/kg Specimen volume, mL0to5 1005to25 50D5194062drain the aqueous phase into the separatory funnel containingthe isooctane. After shaking, allow the phases to separate anddrain the aqueous p
34、hase 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 turns dark blue.10.9 Evaporate the solution to about 30 mL on a hot plate.10.9.1 Warning: Loss of
35、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 nitrate solution and determine the volume oftitrant used to reach the end point.10.11 Determine a blan
36、k 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 itself.11. Procedure for Inorganic Chloride11.1 Follow the procedure in Section 10 but without add
37、ingthe 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. Subtract theinorganic from the total chloride to give the organic chloride.13. Calculation13.1 Calc
38、ulate 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 nitrate solution,V = volume of sample, mL, andD = density or relative density of sample.13.2 Calcu
39、late 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 Bias14.1 Precision:14.1.1 The data for determining the precision of this testmethod are based on the an
40、alyses 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 theacceptability (95 % probability) of results obtained by this testmethod. The criteria were derive
41、d 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 should not beconsidered suspect unless they differ by more than 0.5 mg/kg.14.1.2.2 ReproducibilityR
42、esults 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 available to determine thetrue value.15. Quality Guidelines15.1 Refer to Guide D 6809 for suggested
43、 QA/QC activitiesthat can be used as a part of this method. It is recommendedthat the operator of this method select and perform relevantQA/QC activities like the ones on Guide D 6809 to help ensurethe quality of data generated by this method.16. Keywords16.1 aromatic hydrocarbons; chloride; cyclohe
44、xane; ethyl-benzene; p-xylene; tolueneTABLE 2 Densities of HydrocarbonsComponent DensityBenzene 0.879Cyclohexane 0.779Ethylbenzene 0.867Isopropylbenzene 0.864Toluene 0.866m-Xylene 0.864o-Xylene 0.880p-Xylene 0.861D5194063SUMMARY OF CHANGESCommittee D16 has identified the location of selected changes
45、 to this standard since the last issue(D 5194 04) that may impact the use of this standard. (Approved March 1, 2006.)(1) The rounding statement was updated in 1.5.(2) Section 15 (Quality Control) was added and Guide D 6809was referenced.(3) Summary of Changes was added.Committee D16 has identified t
46、he location of selected changes to this standard since the last issue(D 5194 96 (2000) that may impact the use of this standard.(1) The specification for sodium biphenyl reagent was cor-rected in 6.15.ASTM International takes no position respecting the validity of any patent rights asserted in conne
47、ction 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 responsi
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49、nsideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-
