1、Designation: D 3280 85 (Reapproved 2009)Standard Test Methods forAnalysis of White Zinc Pigments1This standard is issued under the fixed designation D 3280; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A 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 Department of Defense.1. Scope1.1 These test methods cover procedures for the analysi
3、s 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 Matt
4、er 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 in
5、 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 hea
6、lth practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 280 Test Methods for Hygroscopic Moisture (and OtherMatter Volatile Under the Test Conditions) in PigmentsD 1193 Specification for Reagent WaterD 1394 Test Methods for C
7、hemical Analysis of WhiteTitanium PigmentsE11 Specification for Woven Wire Test Sieve Cloth andTest Sieves3. 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 calcula
8、ted.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 D 280.3.2 Leaded Zinc Oxide:3.2.1 Total LeadDetermined as PbSO4and calculated topercent PbO.3.2.2 Total ZincDetermined on the filtrate from proce
9、durein 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 compositionaldata.3.2.5 Moisture and Other Volatile MatterDetermined inaccordance with Method A of Test Methods D 280.3.2.6 Water Solubl
10、e 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 Sec-tions 8 or 9 and calculating ZnO to ZnS.3.3.3 Water Soluble SaltsDetermined in accordance withSection
11、18.3.3.4 MoistureDetermined in accordance with Method Aof Test Methods D 280.3.3.5 Barium SulfateThe sample is treated with N2SO4and Na2CO3and the residue of BaCO3is dissolved in NCl and(NH4)2SO4added to precipitate BaSO4, which is weighed.1These test methods are under the jurisdiction of ASTM Commi
12、ttee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved July 1, 2009. Published July 2009. Originally approvedin 1973. Last previous edition approved in 2004 as D 3280 85 (2004)1.2Fo
13、r 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 website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C70
14、0, West Conshohocken, PA 19428-2959, United States.3.3.6 Titanium DioxideDetermined in accordance withTest Methods D 1394.4. 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 the amounts of these p
15、igments 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 reagents shall conform to the
16、 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 theaccuracy of the determina
17、tion.5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean Type II reagent gradewater conforming to Specification D 1193.5.3 Concentration of Reagents:5.3.1 Concentrated Acids and Ammonium HydroxideWhen acids and ammonium hydroxide are specified by nameor chem
18、ical 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 1.84Ammonium hydroxide,
19、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 ratio stating thenumber
20、 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 finely ground, to afin
21、e 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 finepowder, pass through a 180-
22、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 stoppered bottles or co
23、ntainers.ZINC OXIDE7. Total Zinc, Using Diphenylamine as Internal Indicator7.1 Reagents:7.1.1 Diphenylamine Indicator Solution (10 g/L)Dissolve1 g of diphenylamine 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 to 1 Land add 0.3
24、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 form 400-mL beaker
25、. 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 mL of H2SO4 (1+2) and dilute to 200 mL. Heat to approximately 60C, add2 drops of diphenylamine indicator solution and while stirringvigorously, titrate with K4Fe
26、(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)6solution.About 0.5 t
27、o 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 follows:A 5FV2Z 3 1
28、.245S1G3 100 (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 weightZn (65.38).8. Total Zinc, Using Uranyl Acetate as External Indicator8.1 Reagents:8.1.1
29、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 and water.Cal
30、culate the zinc equivalent of the solution as follows:Z 5 W/V 2 B! (2)where: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 Laborato
31、ryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D 3280 85 (2009)2Z = zinc equivalent of the K4Fe(CN)6solution, g/mL,W = zinc used,V =K4Fe(CN)6solution required for titration of the zinc,mL,
32、 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 until just acid
33、, 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 titration wit
34、h the same amountsof reagents and water.8.3 CalculationCalculate the percent total zinc as ZnO, A,as follows:A 5FV 2 B!Z 3 1.245!SG3 100 (3)where:V =K4Fe(CN)6solution required for titration of thesample, mL,S = sample used, g, and1.245 = molecular weight ZnO (81.38)/molecular weightZn (65.38).9. Tot
35、al Impurities9.1 CalculationCalculate the percent total impurities, A,as follows:A 5 100 2 L 1 Z11 S5! (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 aluminu
36、m.10.1.3 Barium Chloride Solution (100 g BaCl2L)Dissolve 117 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 beenexpelled,
37、 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 warm pl
38、ace 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 3 0.1374!S2G3 100 (5)where:P = BaSO
39、4precipitate, 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 D 280.LEADED ZINC OXIDE12. Total Lead12.1
40、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 weighed Go
41、ochcrucible. 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 zincsh
42、ould 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, and
43、weigh.12.2 CalculationCalculate the percent total lead as PbO,A, as follows:A 5FP13 0.736!S3G3 100 (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 Proce
44、dure: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 zin
45、c on thefiltrate.13.2.2 Evaporate the appropriate filtrate to dryness anddetermine zinc as directed in Sections 7 or 8.D 3280 85 (2009)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, and
46、5 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 as be-fore, and wa
47、sh 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, usin
48、g 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 5FP23 0.343!S4G3 100 (7)where:P2= BaSO4precipitate, g,S4= specimen weight, g, and0.
49、343 = 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 L 1 Z11 S5! (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 D 280.17. Water-Soluble Salts17.1 Procedure:17.1.1 Weigh to the nearest 1 mg about5gofthesampleinto a 500-mL graduated flas
