1、Designation:D398901(Reapproved 2012)Standard Test Method forTotal Rare Earth Metals in Paint Driers by EDTA Method1This standard is issued under the fixed designation D3989;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of
2、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 titrimetric determination ofrare earth metals in liquid rare earth metal driers and utilizesthe
3、 disodium salt of ethylenediaminetetraacetic acid dihydrate(EDTA).1.2 This test method is limited to the determination of therare earth metal content of a liquid rare earth metal drier thatdoes not contain other drier elements.The method is notapplicable to drier blends.1.3 This test method has been
4、 tested in concentrations of6%cerium and 6%rare earth metals,but there is no reason tobelieve that it is not suitable for higher or lower drier metalconcentrations provided specimen size is adjusted accordingly.1.4 The values stated in SI units are to be regarded as thestandard.The values given in p
5、arentheses are for informationonly.1.5 This standard 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 limitati
6、ons prior to use.2.Referenced Documents2.1 ASTM Standards:2D600 Specification for Liquid Paint DriersD1193 Specification for Reagent WaterE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3E300 Practice for Sampl
7、ing Industrial Chemicals3.Summary of Test Method3.1 A diluted solution of the drier is complexed with anexcess of EDTA,the pH adjusted to 5.0,and then titrated withzinc chloride solution to a xylenol orange end point.4.Significance and Use4.1 This test method may be used to confirm the statedcontent
8、 of a pure,liquid rare earth metal drier manufactured foruse in the coatings industry.5.Interferences5.1 Calcium does not interfere at low pH.5.2 All other cations that can be titrated with EDTAin acidicmedia will interfere and must not be present in the drier.6.Reagents6.1 Purity of ReagentsReagent
9、 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 American Chemical Society,where such specifications are available.4Other grades may beused,provided it is first as
10、certained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referenceto water shall be understood to mean reagent water conformingto Type II of Specification D1193.6.3 Ammonium ChlorideAmm
11、onium Hydroxide BufferSolutionAdd 350 mL of concentrated ammonium hydroxide(NH4OH)to 54 g of ammonium chloride(NH4Cl),and diluteto 1 L with water.6.4 Ammonium Hydroxide(NH4OH),(1+1).6.5 Ascorbic Acid.6.6 Eriochrome Black T IndicatorMix and grind thor-oughly in a mortar a mixture of 0.2 g of Eriochro
12、me Black T1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1,2012.Published July 2012.Origi
13、nally approvedin 1981.Last previous edition approved in 2006 as D3989 01(2006).DOI:10.1520/D3989-01R12.2For 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 to the standards Docu
14、ment Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical So
15、ciety,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 an
16、d 100 g of sodium chloride.Store the mixture in a tightlystoppered bottle where it is stable indefinitely.6.7 EDTA,Standard Solution(0.01 M)Weigh about 3.73 gof disodium salt of ethylenediaminetetraacetic acid dihydrateto the nearest 0.01 g,dissolve in water,and dilute to approxi-mately 1 L in a glass-stoppered bottle.6.8 Hydrochloric Acid(HCL),(1+1).6.9 Isopropyl Alcohol(99.5%).6.10 Sodium Acetate-Acetic Acid Buffer SolutionDissolve82 g of sodium acetate in water and dilute to 1 L.Adjust pH to5