1、Designation: D 3804 02Standard Test Method forIron in Paint Driers by EDTA Method1This standard is issued under the fixed designation D 3804; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pa
2、rentheses 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 ofiron in liquid iron driers soluble in isopropyl alcohol andutilizes the disodium salt of e
3、thylenediaminetetraacetic aciddihydrate (EDTA).1.2 This test method is limited to the determination of theiron content of a liquid drier that does not contain other drierelements. This method is not applicable to drier blends.1.3 This standard does not purport to address all of thesafety concerns, i
4、f 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 limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 600 Specification for Liquid Paint Driers2D 1
5、193 Specification for Reagent Water3E 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals4E 300 Practice for Sampling Industrial Chemicals43. Summary of Test Method3.1 The liquid iron drier is diluted with isopropyl alcoholand the
6、 iron chelated with excess standard EDTA. The solutionis buffered and the excess EDTA is titrated with standard zincchloride solution to the Eriochrome Black T end point.4. Significance and Use4.1 This test method may be used to confirm the statedcontent of a liquid iron drier soluble in isopropyl a
7、lcohol andmanufactured for use in the coatings industry. The contentdetermines activity level.5. Interferences5.1 All cations that can be titrated with EDTA in alkalinemedia interfere and must not be present in the sample or mustbe masked.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shal
8、l 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.5Other grades may beused, provided it is first ascertained that the
9、 reagent is ofsufficiently high purity 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 (1+3)Add 10 mL o
10、f concen-trated ammonium hydroxide (NH4OH, sp gr 0.90) to 30 mLwater.6.4 Buffer SolutionAdd 350 mL of concentrated ammo-nium hydroxide (NH4OH) to 54 g of ammonium chloride(NH4Cl) and dilute to 1 L with water.6.5 EDTA, Standard Solution (0.01 M)Weigh to 10 mgabout 3.73 g of the disodium salt of ethyl
11、enediaminetetraaceticacid dihydrate (EDTA), dissolve in water, and dilute toapproximately 1 L in a polyethylene or borosilicate glassbottle.6.6 Hydrochloric Acid (1+3)Add 3 mL of concentratedhydrochloric acid (HCl, sp gr 1.19) to 9 mL of water.6.7 Eriochrome Black-T IndicatorTitrate 0.20 g of thecon
12、centrated dye with 100 g of NaCl and store in a tightlystoppered jar. This mixture remains stable for several years.6.8 Isopropyl Alcohol (99.5 %).6.9 Zinc Chloride, Standard Solution (0.01 M)Weigh to0.5 mg about 0.65 g of zinc (Note 1) onto a glazed paper.Transfer to a 1-L volumetric flask and add
13、25 mL of dilute HCl(7+18) (add 7 mL of concentrated acid (sp gr 1.19) to 18 mLof water). Warm if necessary on a steam bath to dissolvecompletely. Cool, dilute to the mark with water and mix1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and
14、Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved Jan. 10, 2002. Published March 2002. Originallypublished as D 3804 79. Last previous edition D 3804 86 (1996).2Annual Book of ASTM Standards, Vol 06.04.3Ann
15、ual Book of ASTM Standards, Vol 11.01.4Annual Book of ASTM Standards, Vol 15.05.5Reagent 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 Labo
16、ratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand 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.thoroughly. Calculate
17、the exact molarity of this approximately0.01-M solution as follows:M25 W/65.4 (1)where:M2= molarity of ZnCl2solution, andW = zinc used, g.65.4 = atomic weight of zinc.NOTE 1Zinc ribbon cut into small pieces with clean scissors ispreferred. Granular (20 mesh) zinc requires several hours of heating on
18、 asteam bath for complete solution. Store the zinc ribbon in a tightly sealedcontainer to prevent the surface of the zinc from oxidizing.7. Sampling7.1 Take a small sample of liquid drier from bulk using theprocedures in Practice E 300 appropriate for the size ofcontainer, tanks and tank cars or dru
19、ms and cans.NOTE 2Liquid driers are normally homogeneous 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 Practice E 300.7.2 Examine the sample
20、of drier for sediment 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 EDTA, Standard Solution (0.01 M)Transfer 40.0 mLof this
21、solution from a buret into a 250-mL assay beaker orwide-mouthed flask. Add 50 mL of isopropyl alcohol, 10 mL ofbuffer solution, and 0.2 g of indicator (6.7). Mix thoroughly byswirling. Titrate with standard ZnCl2solution (6.9) to the firstpermanent tinge of red. Calculate the exact molarity of thisa
22、pproximately 0.01 M solution as follows:M15 V2M2/V1(2)where:M1= molarity of EDTA solution,V2= ZnCl2solution, mL,M2= molarity of ZnCl2solution, andV1= EDTA solution, mL.9. Procedure9.1 Check the clarity of the drier. If not clear, centrifuge aportion of the sample until it is clear, keeping the centr
23、ifugetube stoppered to prevent solvent evaporation.9.2 Place a few grams of the drier in a 50-mL Erlenmeyerflask fitted with a cork through which passes a dropping tubeand rubber bulb (or medicine dropper) and obtain the totalweight. Weigh by difference to 0.5 mg, 0.18 to 0.22-g speci-mens (8 to 12
24、drops), into 400-mL beakers. This specimen sizeis for driers of 6 % iron content; adjust the size according toexpected percent iron to contain about 0.2 mM of iron. Add100 mL of isopropyl alcohol and 3 mL 1 + 3 HCl to eachspecimen and swirl to mix. Add a few boiling aids and heat thesolution just to
25、 boiling on a hot plate; remove and cool to roomtemperature in a water bath.9.3 From a buret measure 40.0 mL of standard EDTAsolution into each beaker. Neutralize with dilute NH4OH(1 + 3), as indicated by a change in the color of the solutionfrom yellow to reddish. Add 10 mL of the buffer solution a
26、nd0.3 g of the Eriochrome Black-T indicator mixture. Thisaddition should result in a blue-colored solution. Immediatelyback-titrate the excess EDTA with the standard ZnCl2solution(Note 3) to the first permanent tinge of red (Note 4). Theback-titration must be completed within 2 min (Note 5 andNote 6
27、).NOTE 3During the titration stir the solution manually or by means ofa magnetic stirrer.NOTE 4To some observers, this color change appears as a change topurple. However, the transition is sharp and, with a little practice, easilynoted.NOTE 5The time used in the titration step with ZnCl2solution aff
28、ectsthe results. A titration time of less than 2 min gives consistently goodresults. Longer times give higher results.NOTE 6If the end point is overstepped, add 1.0 mL of the EDTAsolution to the mixture and titrate again with standard ZnCl2solution. Usetotal volume of each solution for the calculati
29、on.10. Calculation10.1 Calculate the percent of iron present as follows:Iron, % 5 V3M12 V4M2! 5.59/S (3)where:V3= EDTA solution, mL,M1= molarity of EDTA solution,V4= ZnCl2solution, required for specimen, mL,M2= molarity of ZnCl2solution,S = sample used, g, and5.59 = millimolar weight of Fe 3 10011.
30、Precision and Bias611.1 The precision estimates are based on an interlaboratorystudy in which one operator in seven different laboratoriesanalyzed in duplicate on two different days two samples of irondrier containing 6 and 3 % iron. The 6 % iron drier was acommercially supplied sample and the 3% dr
31、ier was obtainedby quantitative dilution of the 6 % drier. The results wereanalyzed statistically in accordance with Practice E 180 and thewithin-laboratory coefficient of variation was found to be0.26 % relative at 12 degrees of freedom and the between-laboratories coefficient of variation was 1.46
32、 % relative at 10degrees of freedom. Based on these coefficients, the followingcriteria should be used for judging the acceptability of resultsat the 95 % confidence level:11.1.1 RepeatabilityTwo results, each the mean of dupli-cate determinations, obtained by the same operator on differentdays shou
33、ld be considered suspect if they differ by more than0.8 % relative.11.1.2 ReproducibilityTwo results, each the mean of du-plicate determinations, obtained by operators in different labo-ratories should be considered suspect if they differ by morethan 4.6 % relative.6Supporting data are available fro
34、m ASTM International Headquarters. RequestRR: D01-1021.D 3804211.2 BiasBias cannot be determined because there is noaccepted standard for iron in paint driers.12. Keywords12.1 EDTA methods; driers; iron driers; paint driersASTM International takes no position respecting the validity of any patent ri
35、ghts 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 entirely their own responsibility.This standard is subject to revision at an
36、y 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 standardsand should be addressed to ASTM International Headquarters. Your comments w
37、ill 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 on Standards, at the address shown below.This standard is copyrighted by A
38、STM 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 38043
