ASTM D5562-1995(2006) Standard Test Method for Determination of the Acidity as Free Fatty Acids Acid Number in the Presence of Ammonium or Triethanolamine Soaps《存在铵或三乙醇胺皂时酸度作为游离脂肪酸.pdf

1、Designation: D 5562 95 (Reapproved 2006)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 D 5562; the number immediately following the designation indicates the y

2、ear 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. Scope1.1 This test method covers determination of the acidity

3、 asfree fatty acids in the presence of ammonium or triethanola-mine 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 in SI units are to be regarded as the standard.1.3 This stan

4、dard 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.2. Referenced Documents2.1 A

5、STM Standards:2D 5350 Test Method for Determination of OrganicallyCombined 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 assurance.4. Appar

6、atus4.1 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 aborosilicate

7、glass, having a capacity of approximately 300 mLand provided with a glass stopper.4.1.2 Condenser, consisting of a glass tube, 915 mm (36 in.)in length and 8 mm (516 in.) in outside diameter. The lower endof the tube shall be flared and ground to fit the mouth of theErlenmeyer flask.4.1.3 Glass Bead

8、sPerforated glass beads, made of chemi-cally resistant glass, approximately 4 mm (532 in.) 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

9、Indicator Solution (1 g/L)Dissolve 0.1g of methyl orange in 100 mL of water.5.3 Sodium Chloride (NaCl), solid.5.4 Sodium Hydroxide, Standard Solution (1 N)Accurately prepare and standardize a 1 N sodium hydroxide(NaOH) solution. Express the strength or concentration of thesolution as mg of KOH per m

10、L; 1 mL of 1 N NaOH solutionis equivalent to 56.1 mg of KOH.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.(Meth

11、od H 52-1956).Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 1994. Last previous edition approved in 2001 as D 5562 95(2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book

12、of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.FIG. 1 Apparatus for Determination of Organically CombinedSulfuric Anhydride, Method A1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United State

13、s.5.5 Sodium Hydroxide, Standard Solution (0.5 N) Accu-rately prepare and standardize a 0.5 N NaOH solution. Expressthe strength of the solution as mg of KOH per mL; 1 mL of 0.5N NaOH solution is equivalent to 28.05 mg of KOH.5.6 Sulfuric Acid, Standard (0.5 N)Accurately prepareand standardize a 0.5

14、 N sulfuric acid (H2SO4) solution. Expressthe strength of the solution as mg of KOH per mL; 1 mL of 0.5N H2SO4is 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 stirring.6. Procedure6.1 The

15、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 D 5350).6.1.2 Free and Alkali-Combined Fatty A

16、cidsExtract thetotal sulfated and sulfonated fatty matter as described in thedetermination of total active ingredients (see Test MethodD 5350), but omit the dehydration of the extract (see Note 1).Add exactly 0.5 mL of 0.5 N NaOH solution to the extract,evaporate the ether to a volume of approximate

17、ly 25 mL, addapproximately 50 mL of neutral alcohol, and titrate the mixturewith 0.5 N NaOH solution to a phenolphthalein end point.NOTE 1In the presence of acetates, wash the ether layer carefully withconcentrated NaCl solution until one or two drops of 0.5 N NaOH solutionadded to the final wash wa

18、ter are neutral to phenolphthalein indicator.7. Calculation7.1 Calculate the free and alkali-combined fatty acids asdescribed in the determination of acidity as free fatty acids,(see Test Methods D 5350). Calculate the acidity as free fattyacids in the presence of ammonium or triethanolamine soaps,o

19、r both, as follows:K 5 J 2 A (1)or% free fatty acids 5 0.503 K (2)where:K = acid number, mg of KOH/g,J = free and alkali-combined fatty acids, andA = total alkalinity.8. Precision and Bias8.1 This test method is adopted from the procedures of theAmerican Leather Chemists Association, where it has lo

20、ngbeen in use and was approved for publication before theinclusion of precision and bias statements was mandated. Theoriginal interlaboratory test data are no longer available. Theuser is cautioned to verify by the use of reference materials, ifavailable, that the precision and bias (or reproducibil

21、ity) of thistest method is adequate for the contemplated use.9. Keywords9.1 acidity; free fatty acids; leather; sulfonated and sulfatedoilsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this s

22、tandard 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 responsible technical committee and must be reviewed every five years

23、andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee

24、, 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-mail); or through the ASTM website(www.astm.org).D 5562 95 (2006)2