1、Designation: D3280 85 (Reapproved 2014)Standard Test Methods forAnalysis of White Zinc Pigments1This standard is issued under the fixed designation D3280; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods cover procedures for the anal
3、ysis ofwhite zinc pigments.1.2 The analytical procedures appear in the following order:SectionPreparation of Sample 6Zinc OxideTotal Zinc, Using Diphenylamine as Internal Indicator 7Total Zinc, Using Uranyl Acetate as External Indicator 8Total Impurities 9Total Sulfur 10Moisture and Other Volatile M
4、atter 11Leaded Zinc OxideTotal Lead 12Total Zinc 13Total Sulfur 14Total Impurities 15Moisture and Other Volatile Matter 16Water-Soluble Salts 17Zinc SulfideZinc Oxide 18Zinc Sulfide 19Water-Soluble Salts 20Moisture and Other Volatile Matter 21Barium Sulfate 22Titanium Dioxide 231.3 The values stated
5、 in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 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
6、health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D280 Test Methods for Hygroscopic Moisture (and OtherMatter Volatile Under the Test Conditions) in PigmentsD1193 Specification for Reagent WaterD1394 Test Methods for C
7、hemical Analysis of White Tita-nium PigmentsE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Summary of Test Method3.1 Zinc Oxide:3.1.1 Total ZincDetermined using diphenylamine as aninternal indicator and also using uranyl acetate as an externalindicator. Total impurities are calcu
8、lated.3.1.2 Total SulfurDetermined as BaSO4and calculated tosulfur.3.1.3 Moisture and Volatile MatterDetermined in accor-dance with Method A of Test Methods D280.3.2 Leaded Zinc Oxide:3.2.1 Total LeadDetermined as PbSO4and calculated topercent PbO.3.2.2 Total ZincDetermined on the filtrate from proc
9、edurein 13.2.1 in accordance with methods in Sections 7 or 8.3.2.3 Total SulfurDetermined as BaSO4and calculated topercent SO3.3.2.4 Total ImpuritiesCalculated from compositional data.3.2.5 Moisture and Other Volatile MatterDetermined inaccordance with Method A of Test Methods D280.3.2.6 Water Solub
10、le SaltsDetermined gravimetrically.3.3 Zinc Sulfide:3.3.1 Total ZincDetermined using uranyl acetate externalindicator in accordance with Section 9.3.3.2 Zinc SulfideDetermined in accordance with Sections8 or 9 and calculating ZnO to ZnS.3.3.3 Water Soluble SaltsDetermined in accordance withSection 1
11、8.3.3.4 MoistureDetermined in accordance with Method Aof Test Methods D280.3.3.5 Barium SulfateThe sample is treated with N2SO4and Na2CO3and the residue of BaCO3is dissolved in NCl and(NH4)2SO4added to precipitate BaSO4, which is weighed.3.3.6 Titanium DioxideDetermined in accordance withTest Method
12、s D1394.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved Dec. 1, 2014. Published December 2014. Originallyapproved
13、in 1973. Last previous edition approved in 2009 as D3280 85 (2009).DOI: 10.1520/D3280-85R14.2For 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 S
14、ummary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Significance and Use4.1 White zinc pigments find considerable use in whitepaints, and as such it is useful to formulators and users to beable to monitor
15、 the amounts of these pigments in whole paints.It is also of interest to raw material suppliers and paintproducers to check the specifications of each pigment.5. Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagen
16、ts 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 purity to permit its use without lessening theac
17、curacy of the determination.5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type II reagent gradewater conforming to Specification D1193.5.3 Concentration of Reagents:5.3.1 Concentrated Acids and Ammonium HydroxideWhen acids and ammonium hydroxide are sp
18、ecified by nameor chemical formula only it should be understood that concen-trated reagents of the following specific gravities or concen-trations are intended:Acetic acid, HC2H3O299.5 %Hydrochloric acid, HCl sp gr 1.19Hydrofluoric acid, HF 48 %Nitric acid, HNO3sp gr 1.42Sulfuric acid, H2SO4sp gr 1.
19、84Ammonium hydroxide, NH4OH sp gr 0.90The desired specific gravities or concentrations of all otherconcentrated acids are stated whenever they are specified.5.3.2 Diluted Acids and Ammonium HydroxideConcentrations of diluted acids and ammonium hydroxide,except when standardized, are specified as a r
20、atio stating thenumber of volumes of the concentrated reagents to be dilutedwith a given number of volumes of water, as in the followingexample: HCl (1+99) means 1 volume of concentrated HCl (spgr 1.19) diluted with 99 volumes of water.6. Preparation of Sample6.1 Grind dry pigments, if lumpy or not
21、finely ground, to afine powder for analysis. Large samples may be thoroughlymixed and a representative portion taken and powdered iflumpy or not finely ground. Mix the sample in all casesthoroughly before taking specimens for analysis.6.2 Separate pigments from paints or pastes, grind to a finepowde
22、r, pass through a 180-m (No. 80) sieve (Note 1)toremove any skins, thoroughly mix, and oven dry at 105C.Moisten such pigments after weighing with a little alcoholbefore adding reagents for analysis.NOTE 1Detailed requirements for this sieve are given in SpecificationE11.6.3 Preserve all samples in s
23、toppered bottles or containers.ZINC OXIDE7. Total Zinc, Using Diphenylamine as Internal Indicator7.1 Reagents:7.1.1 Diphenylamine Indicator Solution (10 g/L)Dissolve1gofdiphenylamine in 100 mL of H2SO4.7.1.2 Potassium Ferrocyanide (1 mL = 0.008 g Zn)Dissolve 35 g of K4Fe(CN)63H2O in water and dilute
24、 to 1 Land add 0.3 g of potassium ferricyanide (K3Fe(CN)6). Stan-dardize the solution by titrating against zinc (320 to 340 mg),following the procedure described in 7.2. Calculate the gramsof zinc equivalent to 1.00 mL of the solution.7.2 ProcedureWeigh to 0.1 mg about 0.4 g of the sampleinto a tall
25、 form 400-mL beaker. Moisten with about 20 mL ofwater, and dissolve in 15 mL of HCl. Neutralize with NH4OH,using litmus as the indicator.Add an excess of 15 mLof H2SO4(1+2) and dilute to 200 mL. Heat to approximately 60C, add2 drops of diphenylamine indicator solution and while stirringvigorously, t
26、itrate with K4Fe(CN)6solution to the color changefrom purple to a persistent yellowish green.NOTE 2The true end point is a sharp, persistent change from a purpleto a yellowish green. At the beginning of the titration, a deep blue coloris developed after addition of a few millilitres of K4Fe(CN)6solu
27、tion.About 0.5 to 1.0 mL before the true end point is reached, the solutionchanges from a blue to a purple color. After the purple color is developed,the titration should be continued dropwise to the persistent yellowishgreen end point.7.3 CalculationCalculate the percent total zinc as ZnO, A,as fol
28、lows:A 5FV2Z 31.245S1G3100 (1)where:V2=K4Fe(CN)6solution required for titration of thespecimen, mL,Z = zinc equivalent of the K4Fe(CN)6solution, g/mL,S1= specimen weight, and1.245 = molecular weight ZnO (81.38)/molecular weight Zn(65.38).8. Total Zinc, Using Uranyl Acetate as External Indicator8.1 R
29、eagents:8.1.1 Uranyl Acetate Indicator Solution (50 g/L)Dissolve5gofUO2(C2H3O2)22H2O in 100 mL of water and makeslightly acid with acetic acid.8.1.2 Potassium Ferrocyanide, Standard Solution (1mL = 0.008 g Zn)Prepare and standardize as in 7.1.2. Run ablank titration with the same amounts of reagents
30、 and water.Calculate the zinc equivalent of the solution as follows:Z 5 W/V 2 B! (2)where:Z = zinc equivalent of the K4Fe(CN)6solution, g/mL,W = zinc used,3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagent
31、s notlisted by the American Chemical Society, 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.D3280 85 (2014)2V =K4Fe(CN)6solution required for titration of
32、 the zinc,mL, andB =K4Fe(CN)6solution required for titration of the blank,mL.8.2 Procedure:8.2.1 Weigh to 0.1 mg about 0.4 g of the sample into atall-form 400-mL beaker. Moisten with about 20 mL of waterand dissolve by adding 10 mL of HCl. Add NH4OH untilslightly alkaline to litmus paper. Add HCl un
33、til just acid, andthen add 3 mLin excess. Dilute to about 250 mLwith hot waterand heat nearly to boiling. Titrate with K4Fe(CN)6solution,stirring constantly, until a drop of uranyl acetate indicatortested in a white porcelain spot plate shows a brown tinge afterstanding 1 min.8.2.2 BlankRun a blank
34、titration with the same amountsof reagents and water.8.3 CalculationCalculate the percent total zinc as ZnO, A,as follows:A 5FV 2 B!Z 31.245!SG3100 (3)where:V =K4Fe(CN)6solution required for titration of thesample, mL,S = sample used, g, and1.245 = molecular weight ZnO (81.38)/molecular weight Zn(65
35、.38).9. Total Impurities9.1 CalculationCalculate the percent total impurities, A,as follows:A 5 100 2 L1Z11S5! (4)where:L = total lead as PbO, %,Z1= total zinc as ZnO, %, andS5= total sulfur as SO3,%.10. Total Sulfur10.1 Reagents:10.1.1 Bromine Water (saturated).10.1.2 AluminumReagent grade granular
36、 aluminum.10.1.3 Barium Chloride Solution (100 g BaCl2L)Dissolve117 g BaCl22H2O in water and dilute to 1 L.10.2 Procedure:10.2.1 Weigh to 0.1 g about 10 g of the sample into a 400-mL beaker. Add 50 mL of saturated bromine water, 100 mL ofwater, and 35 mL of HCl. Boil until all the bromine has beenex
37、pelled, cool, and add 3 to5gofgranular aluminum. Heat toboiling, filter, and wash well with hot water.10.2.2 Dilute the filtrate to 300 mL with water, neutralizewith NH4OH, and add 6 drops of HCl. Heat to boiling and add25 mL of hot BaCl2solution dropwise, with constant stirring.Allow to stand in a
38、warm place for at least 2 h.10.2.3 Filter, using a weighed Gooch crucible, or a finetextured filter paper and wash well with hot water. Dry andignite in a muffle furnace for 30 min. Cool and weigh asBaSO4.10.3 CalculationCalculate the percent sulfur, A, as fol-lows:A 5FP 30.1374!S2G3100 (5)where:P =
39、 BaSO4precipitate, g,S2= specimen weight, g, and0.1374 = molecular weight of sulfur (32.064)/molecularweight BaSO4(233.43).11. Moisture and Other Volatile Matter11.1 ProcedureDetermine moisture and other volatilematter in accordance with Method A of Test Methods D280.LEADED ZINC OXIDE12. Total Lead1
40、2.1 Procedure:12.1.1 Weigh to the nearest 0.1 mg about 0.5 g of the sampleinto a 400-mL beaker. Dissolve in 250 mL of water and 20 mLof HNO3(Note 2).Add5mLofH2SO4and evaporate to densewhite fumes. Cool, add 50 mL of 95 % alcohol and 200 mL ofwater, and let stand cold 1 to 2 h. Filter, using a weighe
41、d Goochcrucible. Wash the precipitate with H2SO4(1+99) and combinethe filtrate and washings. If the zinc content of the sample isknown to be 40 % or over, reserve the filtrate and washings forthe determination of total zinc (Section 13).NOTE 3If the sample contains calcium or barium, the lead and zi
42、ncshould be separated by precipitation with H2S after solution in HCl,making alkaline with NH4OH and then acid with acetic acid. Dissolve thePbS and ZnS in dilute HNO3and determine the lead and zinc as above.12.1.2 Ignite the precipitate in the crucible at dull red heat(550 6 50C) for 20 min, cool,
43、and weigh.12.2 CalculationCalculate the percent total lead as PbO,A, as follows:A 5FP130.736!S3G3100 (6)where:P1= PbSO4precipitate, g,S3= sample used, g, and0.736 = molecular weight PbO (223.21)/molecular weightPbSO4(303.28).13. Total Zinc13.1 ReagentsSee 7.1 or 8.1, whichever is applicable.13.2 Pro
44、cedure:13.2.1 If the zinc content of the sample is known to be 40 %or over, determine zinc on the filtrate obtained in 12.1.1.Ifthezinc content is known to be under 40 %, weigh to the nearest0.1 mg about1gofthesample, precipitate and filter off thelead as PbSO4as described in 12.1.1, and determine z
45、inc on thefiltrate.13.2.2 Evaporate the appropriate filtrate to dryness anddetermine zinc as directed in Sections 7 or 8.D3280 85 (2014)314. Total Sulfur14.1 ReagentsSee 10.1.3.14.2 Procedure:14.2.1 Weigh to the nearest 0.1 mg about1gofthesample,into a 400-mL beaker. Add 10 mL of water,3gofNH4Cl, an
46、d5 mL of HCl saturated with bromine. Heat on a steam bath forabout 15 min.Add 50 mL of water, neutralize with dry Na2CO3in excess. Boil 10 to 15 min. Allow to settle, dilute to 250 mLwith hot water, filter, and wash with hot water.14.2.2 Redissolve the residue in HCl, reprecipitate asbefore, and was
47、h with hot water. Acidify the combined filtrateswith HCl, adding 5 mL in excess. Boil 10 to 15 min. Neutralizewith NH4OH and add 6 drops excess HCl. Heat to boiling andadd 25 mL of hot BaCl2solution dropwise, with constantstirring. Allow to stand in a warm place for at least 2 h.14.2.3 Filter, using
48、 a weighed Gooch crucible or a finetextured filter paper, and wash well with hot water. Dry andignite in a muffle furnace for 30 min. Cool and weigh.14.3 CalculationCalculate the percent sulfur as SO3, A,asfollows:A 5FP230.343!S4G3100 (7)where:P2= BaSO4precipitate, g,S4= specimen weight, g, and0.343
49、 = molecular weight SO3(80.07)/molecular weightBaSO4(233.43).15. Total Impurities15.1 CalculationCalculate the percent of total impurities,A, as follows:A 5 100 2L1Z11S5!(8)where:L = total lead as PbO, %,Z1= total zinc as ZnO, %, andS5= total sulfur as SO3,%.16. Moisture and Other Volatile Matter16.1 ProcedureDetermine moisture and other volatilematter in accordance with Method A of Test Methods D280.17. Water-Soluble Salts17.1 Procedure:17.1.1 Weigh to the nearest 1 mg about5gofthesampleinto a 500-mL graduated flask. Add 25
