1、Designation: D 5351 93 (Reapproved 2003)Standard Test Method forDetermination of Organically Combined Sulfuric Anhydrideby Extraction Titration, Test Method B1This standard is issued under the fixed designation D 5351; the number immediately following the designation indicates the year oforiginal ad
2、option 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 the determination of the organi-cally combine
3、d sulfuric anhydride existing in a sample ofsulfated oil by extracting the undecomposed sulfated fat andother fatty matter over an acidulated, concentrated salt solu-tion, boiling the residue with sulfuric acid after evaporating thesolvent, and titrating the products of reaction. This test methodis
4、applicable only to sulfated oils that split off their combinedSO3upon boiling with mineral acids, including samplescontaining sodium acetate or other compounds that cannot beaccurately titrated in water solution with methyl orange as theindicator. This test method was derived from Test MethodsD 500,
5、 Sections 20 through 24, and ALCA Method H-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 therespo
6、nsibility 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 ASTM Standards:D 500 Test Methods of Chemical Analysis of Sulfonatedand Sulfated Oils22.2 Other Document:ALC
7、A 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 consists of a glass fla
8、sk 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 approximately 300 mL, an
9、dprovided 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 glass beads, made
10、 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 Solution (1 g/L)Disso
11、lve0.1 g 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 millilitre; 1 mL of 1 NN
12、aOH 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.Express 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
13、(1 + 19)Carefully mix one volume ofconcentrated sulfuric acid (H2SO4, sp gr 1.84) into 19 volumesof water while stirring.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 May 1
14、0, 2003. Published June 2003. Originallyapproved in 1993. Last previous edition approved in 1997 as D 5351 93 (1997).2Annual Book of ASTM Standards, Vol 15.04.3Available from American Leather Chemists Assn., Texas Tech University, P.O.Box 45300, Lubbock, TX 79409.1Copyright ASTM International, 100 B
15、arr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.7 Sulfuric Acid Standard (0.5 N)Accurately prepareand standardize as 0.5 N sulfuric acid (H2SO4) solution.Express the strength of the solution as milligrams of KOH permillilitre; 1 mL of 0.5 N H2SO4is equivalent to 28.0
16、5 mg ofKOH.6. Procedure6.1 The procedure consists 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.
17、 This increase in acidity isdesignated as F.6.1.1 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, an
18、d 50 mL of ether. Shake themixture and neutralize 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
19、alcohol. Allow the mixture in theseparatory funnel 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 was
20、h water strongly alkaline. Allow allseparations 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 al
21、l the ether layers in the decomposition flaskand 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 totaldesu
22、lfated fatty matter (Sections 20 to 24 of Test MethodsD 500). 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 c
23、ombined sulfuric anhydride, % 5 0.1426 3 Fwhere:0.1426 = 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; leathe
24、r; sulfated oils; sulfuric anhydride;titrationASTM 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, a
25、nd 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 andif not revised, either reapproved or withdrawn. Your comments are invited either for revis
26、ion 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, which you may attend. If you feel that your comments have not received a fair hearing you s
27、houldmake 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).FIG. 1 Apparatus for Determination of Organically CombinedSulfuric Anhydride, Method AD 5351 93 (2003)2
