1、Designation: D 1767 89 (Reapproved 2003)Standard Test Method forEthylene Diamine Tetraacetate (EDTA) in Soaps or SyntheticDetergents1This standard is issued under the fixed designation D 1767; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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 ethylenediamine tetraacetate (EDTA) in soaps and s
3、ynthetic detergents.Throughout this test method EDTA represents the hydrateddisodium salt containing 2 moles of H2O. In the chemicalliterature this is frequently abbreviated to Na2H2Y42H2O.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is
4、 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. Material SafetyData Sheets are available for reagents and materials. Reviewthem for hazards prior to usage.2. Referenced Docu
5、ments2.1 ASTM Standards:D 1193 Specification for Reagent Water23. Purity of Reagents3.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the
6、 American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.3.2 Unless otherwise indicated, references to water shall
7、beunderstood to mean reagent water conforming to SpecificationD 1193.4. Reagents4.1 Copper Sulfate Solution (1 mL = 0.0037 g EDTA diso-dium salt)Dissolve 2.497 g of copper sulfate (CuSO45H2O)in water and dilute to 1 L. The actual EDTA equivalent shouldbe determined by the titration of a known weight
8、 of EDTAdisodium salt.4.2 PAN Indicator SolutionDissolve 0.1 g of 1-(2pyridylazo)-2-naphathol4in 100 mL of methyl alcohol.5. Procedure5.1 Weigh to the nearest 0.001ga3to5-gportion of thesample estimated to contain 1 % of EDTA disodium salt. Varythe amount of the sample used depending upon the actual
9、amount of EDTA present. Weigh into a 250-mL beaker, diluteto approximately 75 mL with water, and adjust the pH toapproximately 5.0 by the addition of acetic acid (Note 1). Add4 drops of the PAN indicator solution. Titrate the sample withCuSO4solution to a transition in color from yellow to red.NOTE
10、1Removal of soap fatty acids by filtration through a wet filterpaper prior to titration will sharpen the end point.6. Calculation6.1 Calculate the percentage of EDTA disodium salt in thesample as follows:EDTA, weight % 5 AB/C! 3 100 (1)where:A = millilitres of CuSO4solution required for titration of
11、the sample,B = grams of EDTA disodium salt equivalent to 1 mL of theCuSO4solution, andC = grams of sample used.7. Precision and Bias7.1 The following criteria should be used for judging theacceptability of results (95 % probability):1This test method is under the jurisdiction of ASTM Committee D12 o
12、n Soapsand Other Detergents, and is the direct responsibility of D12.12 on Analysis ofSoaps and Synthetic Detergents.Current edition approved May 26, 1989. Published June 1990. Originallypublished as D 1767 60. Last previous edition D 1767 62 (1984)e1.2Annual Book of ASTM Standards, Vol 11.01.3Reage
13、nt Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand
14、National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.4Eastman Organic Chemical No. 7192 has been found satisfactory for thispurpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.1.1 Liquid SoapDuplicate re
15、sults by the same operatorshould not be considered suspect unless they differ by morethan 60.01 %. The overall reproducibility is 60.03 %.7.1.2 Synthetic DetergentsDuplicate results by the sameoperator should not be considered suspect unless they differ bymore than 60.01 %. The overall reproducibili
16、ty is 60.02 %.8. Keywords8.1 copper sulfate titration; EDTA; ethylene diaminetetraacetateASTM 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 o
17、f 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 andif not revised, either reapproved or withdrawn.
18、 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, which you may attend. If you feel that your comm
19、ents 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 1767 89 (2003)2
