1、Designation: D5351 93 (Reapproved 2017)Standard Test Method forDetermination of Organically Combined Sulfuric Anhydrideby Extraction Titration, Test Method B1This standard is issued under the fixed designation D5351; the number immediately following the designation indicates the year oforiginal adop
2、tion 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 the determination of the organi-cally combined s
3、ulfuric anhydride existing in a sample ofsulfated oil by extracting the undecomposed sulfated fat andother fatty matter over an acidulated, concentrated saltsolution, boiling the residue with sulfuric acid after evaporat-ing the solvent, and titrating the products of reaction. This testmethod is app
4、licable only to sulfated oils that split off theircombined SO3upon boiling with mineral acids, includingsamples containing sodium acetate or other compounds thatcannot be accurately titrated in water solution with methylorange as the indicator. This test method was derived from TestMethods D500, Sec
5、tions 20 through 24, and ALCA MethodH-43.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are provided forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibi
6、lity 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.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in t
7、he 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:2D500 Test Methods of Chemical Analysis of Sulfonated andSulfated Oils2.2 O
8、ther Document:ALCA Method H-43 Organically Combined Sulfuric Anhy-dride Extraction Titration Test (for Sulfated Oils)33. Significance and Use3.1 This test method is intended for the determination oforganically combined sulfuric anhydride in sulfated oils.4. Apparatus4.1 The apparatus required consis
9、ts 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 Flask, an Erlenmeyer flask (Fig. 1) made of borosili-cate glass, having a capacity of approxi
10、mately 300 mL, andprovided with a glass stopper.4.1.2 CondenserThe condenser required consists of aglass tube, 915 mm (36 in.) in length, and 8 mm (516 in.) inoutside diameter. The lower end of the tube shall be flared andground to fit the mouth of the Erlenmeyer flask.4.1.3 Glass Beads, perforated
11、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 methyl orange indicator.5. Reagents5.1 Ethyl Ether:5.2 Methyl Orange Indicator Solu
12、tion (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 milligrams of KOH per millili
13、tre; 1 mL of 1 NNaOH solution is 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.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.08 on
14、 Fats and OilsCurrent edition approved April 1, 2017. Published April 2017. Originallyapproved in 1993. Last previous edition approved in 2009 as D5351 93 (2009).DOI: 10.1520/D5351-93R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servicea
15、stm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Leather Chemists Assn., Texas Tech University, P.O.Box 45300, Lubbock, TX 79409.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
16、t 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 Tr
17、ade Organization Technical Barriers to Trade (TBT) Committee.1Express the strength of the solution as milligrams of KOH permillilitre; 1 mL of 0.5 N NaOH solution is equivalent to 28.05mg of KOH.5.6 Sulfuric Acid (1 + 19)Carefully mix one volume ofconcentrated sulfuric acid (H2SO4, sp gr 1.84) into
18、19 volumesof water while stirring.5.7 Sulfuric Acid Standard (0.5 N)Accurately prepare andstandardize as 0.5 N sulfuric acid (H2SO4) solution. Expressthe strength of the solution as milligrams of KOH per millilitre;1mLof0.5N H2SO4is equivalent to 28.05 mg of KOH.6. Procedure6.1 The procedure consist
19、s of isolating and purifying thefatty matter as it exists in the original oil by dissolving thesample in a solvent, acidifying and washing with saturatedbrine, and determining the increase in acidity upon boiling theisolated product with sulfuric acid. This increase in acidity isdesignated as F.6.1.
20、1 Separation of Purified OilWeigh5to10gofthesample, depending upon the concentration of the fatty matter,into a 250-mL separatory funnel containing 50 mL of concen-trated NaCl solution, some solid NaCl, five drops of methylorange indicator solution, and 50 mL of ether. Shake themixture and neutraliz
21、e with H2SO4(1 + 19) until the lowerlayer is distinctly pink (about 0.2 mL in excess). Highlysulfated oils at this stage may form three layers instead of two.In such cases, use a fat solvent consisting of a mixture of twoparts of ether and one part of alcohol. Allow the mixture in theseparatory funn
22、el to settle for at least 5 min, draw off the lowerlayer into another separatory funnel, and wash the ether layerwith 25-mL portions of NaCl solution until practically neutralto methyl orange, that is, until one drop of 0.5 N NaOHsolution turns the wash water strongly alkaline. Allow allseparations
23、to settle for at least 5 min. Combine the waterlayers, and extract with two 25-mL portions of ether. Combinethe last two ether extractions and wash with NaCl solution untilfree from acid, as in the case of the ether layer in the firstfunnel. Combine all the ether layers in the decomposition flaskand
24、 evaporate the ether.6.1.2 Increase in Acidity upon Boiling, FDetermine theincrease in acidity upon boiling in accordance with theprocedure described for Test Method A in 6.1.2. Reserve thetitrated solution for the subsequent determination of totaldesulfated fatty matter (Sections 20 to 24 of Test M
25、ethodsD500). Make a blank determination as described for TestMethod A in 6.1.1. Calculate the increase in acidity F inaccordance with 6.1.2.7. Calculation7.1 Calculate the percentage of organically combined sul-furic anhydride as follows:Organically combined sulfuric anhydride, % 5 0.1426 3 Fwhere:0
26、.1426 = one tenth the molecular ratio of SO3: KOH, andF = increase in acidity upon boiling.8. Precision and Bias8.1 Although this test method is widely used, precision andbias information is not available at this time.9. Keywords9.1 extraction; leather; sulfated oils; sulfuric anhydride;titrationAST
27、M International 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 en
28、tirely their own responsibility.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 standardsa
29、nd should be addressed 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
30、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
31、at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Apparatus for Determination of Organically CombinedSulfuric Anhydride, Method AD5351 93 (2017)2
