ASTM_D_4711-89R2017.pdf

This international standard was developed in accordance with internationally recognized principleson standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.Designation:D4711-89(Reapproved 2017)Standard Test Method forSulfonic and Sulfuric Acids in Alkylbenzene Sulfonic Acids1This standard is issued under the fixed designation D4711:the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scopelated from the titrant volume between the two inflections.1.1 This test method is applicable to the determination ofwhich is equivalent to the amount of base required forsulfonic and sulfuric acids in branched and linear alkylbenzeneneutralization of the bisulfate anion.sulfonic acids used as intermediates in synthetic detergents.4.Significance and Use1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in this4.1 Alkylbenzene sulfonic acids are important intermediatesstandard.in the synthetic detergent industry and are defined underalkyl1.3 This standard does not purport to address all of thebenzene sulfonatein Terminology D459.This test method issuitable for the rapid monitoring of the sulfonic and sulfuricsafery concerns,if any,associated with its use.It is theacid levels,both of which have a vital bearing on final productresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-performance and appearance.bility of regulatory limitations prior to use.Material SafetyData Sheets are available for reagents and materials.Review5.Interferencesthem for hazards prior to usage.5.1 Strong acids,like nitric and hydrochloric,interfere,asdo weak acids,such as carboxylic acids.Small amounts of2.Referenced Documentswater originally present in the sample do not interfere in the2.1 ASTM Standards:2determination.However,if as much as 5%of water is presentD459 Terminology Relating to Soaps and Other Detergentsin the total solution(solvent plus sample).the end pointE180 Practice for Determining the Precision of ASTMbecomes less sharp.Methods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)6.Apparatus6.1 Potentiometric Titrator,and combination calomel ref-3.Summary of Test Methoderence electrode.3.1 A methanolic solution of the sample is titrated withcyclohexylamine in methanol to yield a potentiometric curve.6.2 Buret Assembly,having a 20 mL buret.4(See Fig.I.)The first inflection represents the neutralization of6.3 Beaker:180 mL tall form.strong acids,such as sulfonics and alkylsulfurics,and the first6.4 Volumetric Flask,Class A,500 mL.hydrogen of sulfuric acid.The second inflection represents theneutralization of the second hydrogen of sulfuric acid.The6.5 Magnetic Stirrer,and stirring bar.amount of sulfonic acid is calculated based on the titrantvolume of the first inflection minus that between the two7.Reagents and Materialsinflections.The amount of sulfuric acid meanwhile is calcu-7.1 Methanol,anhydrous.7.2 Cyclohexylamine(0.10 N)-Dissolve 10 g of reagentThis test method is under the jurisdiction of ASTM Committee D12 on Soapscyclohexylamine in 1000 mL of anhydrous methanol.Stan-and Other Detergents and is the direct responsibility of Subcommittee D12.12 ondardize against sulfamic acid as described in Section 8.Analysis and Specifications of Soaps.Synthetics.Detergents and their Components.Current edition approved Jan.1.2017.Published February 2017.Originally7.3 Sulfamic Acid,acidimetric standard.3approved in 1987.Last previous edition approved in 2009 as D4711-89(2009).DOl:10.1520/D4711-89R17.2 For referenced ASTM standards,visit the ASTM website,www.astm.org.orcontact ASTM Customer Service at serviceastm.org.For Annual Book of A.STM+Metrohm A436.or its equivalent,has been found suitable for this purpose.Standards volume information,refer to the standards Document Summary page onAvailable from Brinkman Instruments.the ASTM website.s J.T.Baker No.4898.or its equivalent,has been found suitable for this purpose.The last approved version of this historical standard is referenced onAvailable from Sargent-Welch Scientific Co.7300 Linder Ave.PO Box 1026.www.astm.org.Skokie,IL 60077.Copyright ASTM Intemnational,100 Barr Harbor Drive,PO Box C700.West Conshohocken,PA 19428-2959.United StatesCopyright by ASTM Intl(all rights reserved):Sat Oct 7 02:58:47 EDT 2017Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorized4D471-89(2017)Grams sample=1.35 meq/meq/g acidity expected(2)400NorE I-Most detergent range alkylbenzene sulfonic acids have a totalacidity of about 3.35 meq/g meaning that the sample weight should beabout 0.35 to 0.45 g.This yields a total titer of about 12 to 15 mL of 0.10N cyclohexylamine and a difference of about 0.45 to 0.68 mL between thetwo breaks for a sample containing about 1.25 sulfuric acid.3009.2 Add a magnetic stirring bar.100 mL of anhydrousmethanol,and stir with a magnetic stirrer until dissolved.9.3 Titrate potentiometrically on the automatic titrator usingthe combination electrode until a curve yielding two breaks is200obtained.(See Fig.1.)9.4 Record the volume of titrant to the first break as Vi,andthat to the second break V2.10010.Calculation10.1 Calculate the weight percent sulfuric acid(H2SO)andweight percent sulfonic acid(RSO,H)as follows:0%HS0.=(V2-V,)(W(98.08)(100)/(W)(1000)(3)%RSO,H=(2V,-V,)(N(MM(100)/W(1000(4)where:100Vi.V2=millilitres of titrant at the first and the second endpoints respectively.101214Nnormality of titrant,Wsample weight,g,andMilliliters-TitrantMWaverage equivalent weight of sulfonic acid.Solvent.MethanolA.Differentiating titration curve11.Precision and Bias6.7Titrant.0.1 N CyclohexylamineB.First derivative curve of the curve A11.1 Repeatability(Single Analyst)-The standard deviationFIG.1 Titration of a detergent intermediate containing alkyl sul-of results(each the average of duplicates)obtained by the samefonic acid and sulfuric acids.analyst on different days,has been estimated to be 0.03%absolute at 14 degrees of freedom.Two such averages shouldbe considered suspect(95 confidence level)if they differ by8.Standardization of 0.10 N Cyclohexylaminemore than 0.08 absolute.8.1 All standardizations should be run in triplicate.This11.2 Reproducibility(Multilaboratory)-The standard de-means separate weighings for solution preparations in 8.2.viation of results(each the average of duplicates)obtained by8.2 Using an analytical balance,accurately weigh 0.10 toanalysts in different laboratories,has been estimated to be0.12 g of sulfamic acid to the nearest 0.1 mg into a 180 mL tall0.05 absolute at 13 degrees of freedom.Two such averagesform beaker.Dissolve in 100 mL of anhydrous methanol.Mixshould be considered suspect(95 confidence level)if theywell.differ by more than 0.16 absolute.8.3 Titrate with 0.10N cyclohexylamine using the combina-11.3 Checking Limits for Duplicates-Report the activetion electrode on the automatic titrator until the completecontent of the sample to the nearest 0.01%Duplicate runs thatdevelopment of a single break.Record the mL at the inflectionagree within 0.1 are acceptable for averaging(95 confi-point.dence level).SULFONIC ACID PERCENT8.4 Calculate the normality of the cyclohexylamine solutionas follows:11.4 Repeatabiliry(Single Analyst)-The standard deviationof results(each the average of duplicates)obtained by the sameNormality of Cyclohexylamine(G)(1000)/(M)(97.09)(1)analyst on different days,has been estimated to be 0.16%where:absolute at 14 degrees of freedom.Two such averages shouldG grams of sulfamic acid,andbe considered suspect(95 confidence level)if they differ byM mL of cyclohexylamine to inflection point.more than 0.48 absolute.11.5 Reproducibility(Multilaboratory)-The standard de-9.Procedureviation of results(each the average of duplicates)obtained by9.1 Using an analytical balance,accurately weigh 1.2 to 1.5analysts in different laboratories,has been estimated to bemeq to the nearest 0.1 mg of sample directly into a 180 mL tallform beaker.Sample size may be calculated from the follow-Supporting Data on file at ASTM Headquarters.Request RR:D12-1009.ing:7 Practice E180 was used to determine precision and bias.Copyright by ASTM Intl(all rights reserved);Sat Oct 7 02:58:47 EDT 20172Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorizedD4711-89(2017)0.36%absolute at 13 degrees of freedom.Two such averagesNoTE 2-The precision data were derived from results of cooperativeshould be considered suspect(95%confidence level)if theytests by sixteen laboratories on a linear alkylbenzene sulfonic acid havingdiffer by more than 1.1%absolute.an average equivalent weight of 318.11.6 Checking Limits for Duplicates-Report the active12.Keywordscontent of the sample to the nearest 0.01%.Duplicate runs thatagree within 0.45%are acceptable for averaging(95%con-12.1 alkylbenzene sulfonic acid;sulfonic acid;sulfuric acid;fidence level).titration11.7 Bias-Since there is no accepted reference materialsuitable for determining the bias for the procedure in this testmethod,no statement on bias is being made.ASTM Intemational takes 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 responsibility.This standard is 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be secured from the Copyright Clearance Center,222Rosewood Drive,Danvers,MA 01923,Tel:(978)646-2600;http:/ by ASTM Intl(all rights reserved);Sat Oct 7 02:58:47 EDT 20173Downloaded/printed byUniversity of Edinburgh(University of Edinburgh)pursuant to License Agreement.No further reproductions authorized.