1、Designation: D 3634 99 (Reapproved 2005)e1Standard Test Method forTrace Chloride Ion in Engine Coolants1This standard is issued under the fixed designation D 3634; 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 (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOTEIn 10.3, the solution was corrected editorially t
3、o AgNo3in June 2006.1. Scope1.1 This test method covers the determination of chlorideion in engine coolants in the range from 5 to 200 ppm in thepresence of up to 0.6 weight % mercaptobenzothiazole.1.2 Other materials that react with silver ion will interfere.1.3 Chloride in engine coolants containi
4、ng an aryltriazoleinstead of mercaptobenzothiazole can be determined directlyby this test method without pretreatment with hydrogen per-oxide.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport
5、 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. Specific hazardsstatements are given in Section
6、7.2. Referenced Documents2.1 ASTM Standards:2D 1176 Practice for Sampling and Preparing Aqueous So-lutions of Engine Coolants or Antirusts for Testing Pur-posesD 1193 Specification for Reagent WaterE 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for Ch
7、emicalAnalysis2.2 Manufacturing Chemists Association Document:3MCA Chemical Safety Data Sheet SD-533. Summary of Test Method3.1 The sample is first treated at a pH of 12 to 13 withaqueous hydrogen peroxide to oxidize the mercaptobenzothia-zole to soluble, noninterfering sulfonate. The treated sample
8、 isdissolved in glacial acetic acid and titrated potentiometricallywith dilute standard silver nitrate solution. Since the solubilityof silver chloride in this system is sufficient to preventobtaining a suitable inflection at the very low limit of the testmethod, some chloride is deliberately added
9、to the glacialacetic acid solvent and then corrected for by a blank titration.4. Significance and Use4.1 This test method permits the determination of very lowlevels of chloride ion in engine coolants containing thecommon corrosion inhibitor, mercaptobenzothiazole, or relatedmercaptans, which would
10、normally interfere with the titrationby also forming insoluble silver salts with silver nitrate.5. Apparatus5.1 Manual Titrations:5.1.1 pH MeterAn expanded scale pH meter which can beread to 1 or 2 mV is desirable but not required. A silver billetindicator electrode4and glass reference electrode5are
11、 used forthe chloride titration. The silver electrode should be polishedoccasionally with fine steel wool or scouring powder andthoroughly rinsed.5.1.2 Buret, 10-mL, micro, Class A, calibrated in 0.02-mLdivisions.1This test method is under the jurisidiction of ASTM Committee D15 on EngineCoolants an
12、d is the direct responsibility of Subcommittee D15.04 on ChemicalProperties.Current edition approved Oct. 1, 2005. Published November 2005. Originallyapproved in 1977. Last previous edition approved in 1999 as D 3634 99e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontac
13、t 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 the Manufacturing Chemists Association, 1825 ConnecticutAve., Washington, DC 20009.4The sole source of supply of the Silver
14、 Billet Electrode known to the committeeat this time is Fisher Scientific (, Catalog No. 13-620-122). If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical
15、 committee,1which you may attend.5The sole source of supply of the reference electrode known to the committee atthis time is Fisher Scientific (, Catalog No. 13-620-216). If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will r
16、eceive careful consideration at ameeting of the responsible technical committee,1which you may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.3 Beakers, electrolytic, 250-mL tall form.5.2 Automatic Titrators are satisfact
17、ory for this test method,provided they exhibit resolution and accuracy equivalent tothat specified for manual titrations.5.3 Pipets, 10, 20, and 100-mL, Class A.5.4 Flask, Erlenmeyer, 250 mL, with a 24/40 standard taper,female ground glass joint.5.5 CondenserThe condenser shall be of the water-coole
18、d, reflux, glass-tube type, having a condenser jacketapproximately 200 mm in length. The bottom end of thecondenser shall have a 24/40 male ground glass joint to matchthe Erlenmeyer flask.5.6 Flask, volumetric, 200 mL, Class A.NOTE 1All glassware should be thoroughly cleaned and reserved foruse in t
19、his test method. Great care must be exercised to avoid contami-nation. Glassware should be cleaned with chromic acid (WarningSee7.1.) cleaning solution, then thoroughly rinsed with water, then withacetone (WarningSee 7.2.), and dried.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemi
20、cals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.6Other grades may beused, provided it is first ascertained
21、 that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterReferences to water shall be under-stood to mean Type IV reagent water conforming to Specifi-cation D 1193: total particulate and dissolved matter, 2.0 mg/Lmaximum;
22、 pH at 25C, 5.0 to 8.0; electrical conductivity at25C, 5.0 mho/cm maximum; minimum color retention timeof potassium permanganate, 10 min.6.3 Acetic Acid, Glacial (WarningSee 7.3.).6.4 Hydrogen Peroxide Solution(WarningSee 7.4.)Use 30 mass % hydrogen peroxide (H2O2), reagent grade.Aged or contaminate
23、d H2O2can undergo considerable decom-position and cause incomplete oxidation of the sulfur com-pounds with subsequent high apparent chloride values; there-fore, fresh reagent should be used.6.5 Potassium Chloride SolutionDissolve 0.20 6 0.02 gof potassium chloride (KCl) in 100 mL of water. The solut
24、ionwill contain 1 mg of chloride per mL solution.6.6 Silver Nitrate Solution(WarningSee 7.5.) Prepare astandard 0.01 N silver nitrate (AgNO3) solution weekly bydiluting 10 mL of standard 0.1 N aqueous AgNO3solution to100 mL with water. The 0.1 N standardAgNO3solution shouldbe prepared and standardiz
25、ed in accordance with Sections 44 to48 of Practice E 200.6.7 Sodium Hydroxide Solution(WarningSee 7.6.) Pre-pare a 20 mass % sodium hydroxide (NaOH) solution in water.7. Hazards7.1 Chromic AcidHighly toxic; cancer suspect agent;corrosive; avoid skin contact.7.2 AcetoneExtremely flammable; harmful if
26、 swallowedor inhaled; causes irritation.7.3 Acetic Acid, GlacialPoison, causes severe burns;combustible; harmful if swallowed or inhaled.7.4 Hydrogen Peroxide SolutionStrong oxidizer; contactwith other material may cause fire; causes severe burns. Do nottightly stopper containers. For further detail
27、s, see MCAChemi-cal Safety Data Sheet SD-53.7.5 Silver NitrateMay be fatal if swallowed; causes se-vere burns.7.6 Sodium Hydroxide SolutionCauses severe burns toskin and eyes.8. Sampling8.1 Sampling of engine coolant should be carried out inaccordance with Practice D 1176.9. Preparation of Titration
28、 Solvent9.1 Determine a titration blank on a full 2.3-kg bottle ofglacial acetic acid by titrating 100 mL potentiometrically with0.01 N AgNO3solution. If the blank is more than 0.2 mL of0.01 N AgNO3solution, reject the bottle. If the blank is lessthan 0.05 mL of titrant, add an amount of the KCl sol
29、ution (1mL maximum) to the glacial acetic acid remaining in the bottle(about 2300 mL) to give an approximately 0.1-mL titration for100 mL of the acetic acid. Determine the blank on exactly 100mL of this titration solvent in duplicate. The values should notdiffer by more than 0.02 mL. Reserve the sup
30、ply of solvent forthis test method and recheck the blank occasionally.6Reagent 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 LaboratoryChem
31、icals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD. FIG. 1 Titration Curves for Trace Chloride in Engine AntifreezesD 3634 99 (2005)e1210. Procedure10.1 To a 250-mL Erlenmeyer flask add 50 6 0.1gof
32、engine coolant and approximately 30 mL of water. Make thesolution strongly alkaline by the addition of 5 mLof 20 mass %aqueous NaOH solution. Add 5 mL of 30 mass % aqueousH2O2with stirring, then connect the flask to a reflux condenserand reflux for 30 min. Cool the solution to room temperatureand tr
33、ansfer the contents quantitatively to a 200-mL volumetricflask and dilute to volume with water.10.2 In a 200-mL volumetric flask, prepare a blank byadding 5 mL of 30 mass % aqueous H2O2and the same amountof 20 mass % aqueous NaOH solution used in 10.1 and diluteto 200 mL with water.10.3 Pipet 100 mL
34、 of the glacial acetic acid titration solventinto each of two beakers.Accurately pipet 20 mL of the treatedengine coolant sample into one beaker and 20 mL of the blank(10.2) into the second beaker and allow to dissolve. Titrate thecontents of each beaker potentiometrically with 0.01 N AgNO3solution
35、while stirring slowly with a magnetic stirrer. Theequilibration of electrode potentials is slow in the vicinity ofthe end point; therefore, the titrant should be added in 0.02-mLincrements in this region and sufficient time allowed for stablereadings to be obtained.11. Calculation11.1 Chloride Conte
36、nt:11.1.1 Prepare a titration curve by plotting potential read-ings, using 2 mV per division, against the correspondingvolume of titrant added, using 0.02 mL per division. The endpoint is selected at the middle of the steepest portion of thecurve (see Fig. 1).11.1.2 Calculate ppm of the chloride ion
37、 in the originalengine coolant sample as follows:Chloride, ppm 5V 2 B! N! 35.5! 200! 106!20! 50! 1000!5 V 2 B!N!7100!where:V = titrant used, mL, in the engine coolant sample,B = titrant used, mL, in the blank sample, andN = normality of titrant.12. Report12.1 Report the chloride content of the engin
38、e coolant tothe nearest unit.13. Precision and Bias13.1 The reproducibility of the chloride ion determinationby this test method is 5 ppm in the range from 5 to 200 ppm.13.2 The bias for this test method has not been determined.14. Keywords14.1 engine coolants; trace chlorideASTM International takes
39、 no position respecting the validity 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 resp
40、onsibility.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
41、d to ASTM International Headquarters. Your comments will receive careful consideration 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
42、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-mail); or through the ASTM website(www.astm.org).D 3634 99 (2005)e13
