1、Designation: D 3969 01 (Reapproved 2006)Standard Test Method forZirconium in Paint Driers by EDTA Method1This standard is issued under the fixed designation D 3969; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. 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 titrimetric determination ofzirconium in zirconium driers used in the coatings industry andutil
3、izes the disodium salt of ethylenediaminetetraacetic aciddihydrate (EDTA).1.2 This test method is limited to the determination of thezirconium content of a liquid zirconium drier that does notcontain other drier elements. The test method is not applicableto drier blends and does not differentiate ha
4、fnium fromzirconium.1.3 All cations that can be titrated with EDTA in acid mediainterfere and must not be present in the sample.1.4 This test method has been tested for concentrations of 6and 12 % zirconium, but there is no reason to believe that it isnot suitable for higher or lower zirconium conce
5、ntrations,provided specimen size is adjusted proportionately.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is the
6、responsibility 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:2D 600 Specification for Liquid Paint DriersD 1193 Specification for Reagent WaterE 180
7、Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 300 Practice for Sampling Industrial Chemicals3. Summary of Test Method3.1 The zirconium drier is digested with concentrated sul-furic acid and 30 % hydrogen peroxide to destroy all
8、 organicmatter. The diluted solution is boiled with an excess of EDTA,the pH adjusted, and the excess titrated with bismuth nitrateusing xylenol orange as the indicator.4. Significance and Use4.1 The amount of zirconium drier used in oxidizing-typecoatings significantly affects their drying properti
9、es. This testmethod may be used to confirm the stated content of a pureliquid zirconium drier manufactured for use by the coatingsindustry.5. Apparatus5.1 Centrifuge, capable of developing 1000 to 2000 g.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless other
10、wise 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.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high pur
11、ity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type II of Specification D 1193.6.3 Ammonium Hydroxide (sp gr 0.90)Concentrated, am-monium hydroxide (NH4O
12、H).6.4 Bismuth Nitrate, Standard Solution (0.05 M)Dissolve24.25 g of bismuth nitrate (Bi(NO3)5H2O) in 20 to 30 mL ofconcentrated nitric acid (use a magnetic stirrer if possible).After solution is complete, dilute to 1 L with water.NOTE 1Add the water very slowly to the acid solution, while cooling1T
13、his 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, 2006. Published June 2006. Originallyap
14、proved in 1980. Last previous edition approved in 2001 as D 3969 01.2For 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 Document Summary page onthe ASTM w
15、ebsite.3Reagent 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 Pha
16、rmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the flask in an ice bath to prevent splattering.6.5 EDTA, Standard Solution (0.05 M)Dissolve 18
17、.61 gof EDTA in 300 to 500 mL of water and dilute to 1 L. Store ina polyethylene or borosilicate glass bottle.6.6 Eriochrome Black-T IndicatorTriturate 0.100 g ofpowdered Eriochrome Black-T with 100 g of sodium chloride(NaCl), and store the mixture in a tightly stoppered bottle. Thismixture remains
18、stable for several years.6.7 Formic Acid (sp gr 1.22, 90 %) HCOOH.6.8 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).6.9 Hydrogen Peroxide (30 %).6.10 Isopropyl Alcohol (99.5 %).6.11 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).6.12 Phenolphthalein Indicator (1.0 %)Dis
19、solve 1.0 g ofphenolphthalein indicator in 100 mL of methanol, ethanol, orisopropanol.6.13 Sodium Sulfite (Na2SO3).6.14 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid(H2SO4).6.15 Xylenol Orange (0.2 %)Dissolve 0.2 g in 100 mL ofwater. Prepare fresh each day used.6.16 Zinc Chloride, Standard So
20、lution (0.100 M) Dis-solve 6.538 g of zinc ribbon (Note 2) in concentrated HCl,keeping the excess of acid as small as possible. After the zinchas dissolved, cool to room temperature and dilute to 1 L in avolumetric flask.NOTE 2Store the zinc ribbon in a tightly closed container to preventthe surface
21、 of the zinc from oxidizing.7. Sampling7.1 Take a small sample of liquid drier from bulk using theprocedure in Practice E 300 appropriate for the size of thecontainer: section on Bottle Sampling for tanks and tank cars,or section on Tube Sampling for drums and cans.NOTE 3Liquid driers are normally h
22、omogeneous so that only simplephysical tests, such as specific gravity or solids content, on top and bottomsamples from tanks, are required to confirm that separation has notoccurred. Agitate drums in accordance with section on Tube Sampling inPractice E 300.7.2 Examine the sample of drier for sedim
23、ent or suspendedmatter which, if present, is evidence of noncompliance withSpecification D 600.7.3 If the sample is homogeneous keep it in a stopperedvessel to prevent solvent evaporation prior to analysis.8. Standardization8.1 Zinc Chloride, Standard Solution (0.100 M)Calculatethe molarity, M1, of
24、the zinc chloride (ZnCl2) solution asfollows:M15S165.37(1)where:S1= zinc used, g, and65.37 = zinc to producea1Msolution, g/L.8.2 EDTA, Standard Solution (0.05 M)Pipet 20 or 25-mLportions (use calibrated pipets) of the standard ZnCl2solutioninto a 250-mL Erlenmeyer flask. Add concentrated NH4OHdropwi
25、se until the precipitate which forms redissolves. Add 3mL more of NH4OH. Add 0.20 to 0.25 g Eriochrome Black-Tindicator mixture and titrate with EDTA until the solutionchanges from red to clear blue.8.2.1 Calculate the molarity of the EDTA solution, M2,asfollows:M25 V1M1/V2(2)where:V1= volume of ZnC
26、l2solution, mL, andV2= volume of EDTA solution, mL.8.3 Bismuth Nitrate, Standard Solution (0.05 M)Pipet 24mL of 0.05 M EDTA into a 250-mL Erlenmeyer flask, add 75mL of distilled water, neutralize with concentrated NH4OH toa pink end point with phenolphthalein, and then add 15 mL ofconcentrated formi
27、c acid. After cooling to room temperature,titrate with 0.05 M bismuth nitrate solution and xylenol orangefrom a yellow to a pink end point.8.3.1 Calculate the molarity, M3, of the Bi(NO3)3solutionas follows:M35V3M2V4(3)where:M3= molarity of Bi(NO3)3solution,V3= 24.0 mLM2= molarity of EDTA solution,
28、andV4= volume of Bi(NO3)3solution, mL.9. Procedure9.1 Check the clarity of the drier. If not clear, centrifuge aportion of the sample until it is clear, keeping the centrifugetube stoppered to prevent solvent evaporation.9.2 Place a few grams of the drier in a 50-mL Erlenmeyerflask fitted with a cor
29、k through which passes a dropping tubeand rubber bulb (or a medicine dropper) and obtain the totalweight. Into another Erlenmeyer flask, weigh by difference to0.5 mg, a specimen of the appropriate size: (a) 0.6 to 0.7 g for6% Zr, (b) 0.3 to 0.35 g for 12 % zirconium, and (c)proportionate amounts for
30、 more or less Zr. Add several glassbeads, 5 mL of concentrated H2SO4, and 10 mL of 30 % H2O2and heat on the hot plate until white fumes appear. Destroy allthe organic matter by further additions of hydrogen peroxide in10-mL increments.9.3 Cool (25 to 30C), add 75 mL of water, not less than 0.2gofNa2
31、SO3and boil for 5 min (Note 4). Add to the warmsolution 25 mL of 0.05 M EDTA and heat to boiling.NOTE 4If the solution turns milky red after the addition of Na2SO3,boiling will make it clear. Sometimes a black precipitate forms at this timealso. Disregard it since it does not interfere with the endp
32、oint.9.4 Allow the solution to cool and neutralize with concen-trated NH4OH to a pink end point using phenolphthaleinindicator. Add 15 mL of concentrated formic acid and aftercooling to room temperature in an ice bath, add 6 to 8 drops ofxylenol orange and titrate with standard Bi(NO3)3solutionfrom
33、a yellow to a pink end point.D 3969 01 (2006)2NOTE 5Because the color of metal indicators (and some of their metalcomplexes) is affected by pH changes, the pH must be kept constantduring titration by the recommended buffer during the titration.10. Calculation10.1 Calculate the percent of metal, A,(N
34、ote 6) present aszirconium as follows:A 5 V4M22 V5M3!9.122S2(4)where:V4= volume of EDTA solution, mL.V5= volume of Bi(NO3)3solution, mL,9.122 = millimolar weight of zirconium 3 100, andS2= specimen weight, g.NOTE 6Zirconium driers may contain up to 5 % of the total metal ashafnium. However, the typi
35、cal hafnium content would be 1.6 6 0.1 % ofthe total metal present. The rest would be zirconium. Based on supplierresults, there is no difference in the activity of hafnium versus zirconiumin paints.11. Precision and Bias411.1 PrecisionThe precision estimates are based on aninterlaboratory study in
36、which one operator in six differentlaboratories analyzed in duplicate on two different days twosamples of zirconium drier containing 6 and 12 % zirconium.The zirconium drier was a commercially supplied sample. Theresults were analyzed statistically in accordance with PracticeE 180, and the within-la
37、boratory coefficient of variation wasfound to be 0.46 % relative at 12 df and the between-laboratories coefficient of variation was 1.61 % relative at 10df. Based on these coefficients, the following criteria should beused for judging the acceptability of results at the 95 %confidence levels:11.1.1
38、RepeatabilityTwo results, each the mean of dupli-cate determinations, obtained by the same operator on differentdays should be considered suspect if they differ by more than1.42 % relative.11.1.2 ReproducibilityTwo results, each the mean of du-plicate determinations, obtained by operators in differe
39、nt labo-ratories should be considered suspect if they differ by morethan 5.0 % relative.11.2 BiasBias cannot be determined because there are noaccepted standards for zirconium in paint driers.12. Keywords12.1 analysis; EDTA method; liquid driers; paint driers;zirconium drierASTM International takes
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43、ddress 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).4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D01-1031.D 3969 01 (2006)3
