ASTM_D_8284_-_19.pdf

Designation:D828419Standard Test Method forDetermination of the Total Alkalinity in Sulfated,SulfonatedOils and Fatliquors1This standard is issued under the fixed designation D8284;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method determines the total alkalinity of thefixed alkali,ammonia and triethanolamine which are bound assoap;free alkali,and the alkalinity of titratable alkaline salts,but not that of non-titratable alkaline salts.1.2 Applicable to sulfated,sulfonated oils and fatliquorsused in the softening and stuffing of leather.1.3 This standard 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Apparatus3.1 The apparatus required consists of an Erlenmeyer flask,250 or 300 mL,provided with a glass stopper.4.Reagents4.1 Sodium Hydroxide,Standard Solution(0.5 N)Accurately prepare and standardize a 0.5 N NaOH solution.Express the concentration of the solution as milligrams ofKOH per milliliter;1 mL of 0.5 N NaOH solution is equivalentto 28.05 mg of KOH.4.2 Sulfuric Acid,Standard(0.5 N)Accurately prepare andstandardize a 0.5 N sulfuric acid(H2SO4)solution.Express theconcentration of the solution as milligrams of KOH permilliliter;1 mL of 0.5 N H2SO4is equivalent to 28.05 mg ofKOH.4.3 Diethyl EtherA.C.S.grade.4.4 HexaneA.C.S.grade.4.5 Sodium Chloride(NaCl)A.C.S.grade.4.6 Methyl Orange Indicator Solution(1 g/L)Dissolve0.1 g of methyl orange in 100 mL of water.5.Procedure5.1 Dissolve 10 g of the sample in 100 mL of water in a300-mL glass-stoppered Erlenmeyer flask,warming to obtain asolution,if necessary.After cooling,add 30 g of NaCl,25 mLof Diethyl Ether or Hexane,and five drops of methyl orangeindicator solution.Slowly add 0.5 N H2SO4,a few drops at atime,swirling the flask frequently to combine until the mixtureis slightly acidic and the color shifts,from yellow to amber-red.Stopper and shake the contents of the flask vigorously,repeat-ing until vigorous shaking does not cause the color shift torevert.Complete the titration by adding 0.5 N NaOH solutionseveral drops at a time,until the solution is alkaline.Back-titrate with acid,one or two drops at a time until the end pointis reached.Shake the solution vigorously after each addition ofreagent.Wait 3 min before taking readings of the burette.6.Calculation6.1 The total alkalinity is expressed as mg KOH/g;calculateit as follows:A 5B 3 D!2C 3 E!#356.1W(1)where:A=total alkalinity,mg of KOH/g,B=millilitres of H2SO4required for titration of the sample,C=millilitres of NaOH solution required for titration of thesample,D=titer of H2SO4,Standard solution(0.5 N)E=titer of NaOH solution,Standard solution(0.5 N)1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.08 on Fats and Oils.Current edition approved Sept.1,2019.Published September 2019.DOI:10.1520/D8284-19.2For 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 website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on 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.1 W=weight of sample,g.7.Precision and Bias7.1 The precision of this test method is based on aninter-laboratory study of WK67188,Standard Test method forthe Determination of Total Alkalinity,conducted in 2018.Sixlaboratories tested five leather oils.Every“test result”repre-sents an individual determination,and all participants reportedthree replicate test results per material.Practice E691 wasfollowed for the design of the study and analysis of the data;the details are given