1、Designation:D556295(Reapproved 2018)Standard Test Method forDetermination of the Acidity as Free Fatty Acids/AcidNumber in the Presence of Ammonium or TriethanolamineSoaps1This standard is issued under the fixed designation D5562;the number immediately following the designation indicates the year of
2、original 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 covers determination of the acidity asfree fatty
3、acids in the presence of ammonium or trietha-nolamine soaps,or both,existing in a sample of sulfonated orsulfated oil,or both,by calculation from the total alkalinity andfree-and-alkali combined fatty acids.1.2 The values stated in SI units are to be regarded asstandard.1.3 This standard does not pu
4、rport 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 w
5、as 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
6、Documents2.1 ASTM Standards:2D5350 Test Method for Determination of Organically Com-bined Sulfuric Anhydride by Titration,Test Method A3.Significance and Use3.1 This test method is intended for use in the determinationof the acid number of sulfonated and sulfated oils for thepurpose of quality assur
7、ance.4.Apparatus4.1 The apparatus required consists of a glass flask providedwith a glass stopper and an air condenser.The connectionbetween the flask and the condenser shall be a ground joint.Perforated glass beads shall be used to prevent bumping.4.1.1 FlaskAn Erlenmeyer flask(Fig.1)made of a boro
8、-silicate glass,having a capacity of approximately 300 mL andprovided with a glass stopper.4.1.2 Condenser,consisting of a glass tube,915 mm(36 in.)in length and 8 mm(516in.)in outside diameter.The lower endof the tube shall be flared and ground to fit the mouth of theErlenmeyer flask.4.1.3 Glass Be
9、adsPerforated glass beads,made of chemi-cally resistant glass,approximately 4 mm(532in.)in diameter.Before using,the glass beads shall be boiled thoroughly inseveral portions of water or until the wash water reacts neutralto a methyl orange indicator.5.Reagents5.1 Ethyl Ether.5.2 Methyl Orange Indic
10、ator Solution(1 g/L)Dissolve 0.1g of methyl orange in 100 mL of water.5.3 Sodium Chloride(NaCl),solid.5.4 SodiumHydroxide,StandardSolution(1N)Accurately prepare and standardize a 1 N sodium hydroxide(NaOH)solution.Express the strength or concentration of thesolution as mg of KOH per mL;1 mL of 1 N N
11、aOH solutionis equivalent to 56.1 mg of KOH.5.5 Sodium Hydroxide,Standard Solution(0.5 N)Accurately prepare and standardize a 0.5 N NaOH solution.Express the strength of the solution as mg of KOH per mL;1mLof 0.5 N NaOH solution is equivalent to 28.05 mg of KOH.5.6 Sulfuric Acid,Standard(0.5 N)Accur
12、ately prepare andstandardize a 0.5 N sulfuric acid(H2SO4)solution.Express thestrength of the solution as mg of KOH per mL;1 mL of 0.5 NH2SO4is equivalent to 28.05 mg of KOH.5.7 Sulfuric Acid(1+19)Carefully mix 1 volume ofconcentrated sulfuric acid(H2SO4,sp gr 1.84)into 19 volumesof water while stirr
13、ing.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.This testmethod was developed in cooperation with the American Leather Chemists Assn.(Method H 52-1956).Current edition approved Sept.1,2018.Publis
14、hed October 2018.Originallyapproved in 1994.Last previous edition approved in 2011 as D5562 95(2011).DOI:10.1520/D5562-95R18.2For 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
15、 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
16、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 6.Procedure6.1 The procedure consists of two determinations:(1)totalalkalinity and(2)free-and-alkali-combined fatty acids.6.1.1 Total AlkalinityDetermine the total alkalinity asdescribed in the determination of organically combined sulfu-ric anhydride(see Test Method D5350).6.1.2 Free and Alkali-Combined Fatty Acids
