1、Designation:D184486(Reapproved 2014)Standard Test Methods forChemical Analysis of Basic Lead Silicochromate1This standard is issued under the fixed designation D1844;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last re
2、vision.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 These test methods cover the chemical analysis of thepigment commercially known as basic lead silicochromate andare applicable to
3、pigment supplied by the manufacturer and topigment,but not mixed pigments,separated from liquidcoatings.The presence of basic lead silicochromate speciesshall be confirmed by X-ray diffraction analysis(see Specifi-cation D1648).1.2 For liquid coatings the pigment must first be separatedfrom the vehi
4、cle before conducting the analysis.1.3 The analytical procedures appear in the following order:SectionsLead oxide6 to 14Chromium trioxide15 to 23Silica24 to 27Moisture and other volatile matter28Coarse particles29Oil absorption30Mass color and tinting strength311.4 The values stated in SI units are
5、to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 This standard does not purport to address the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine
6、 the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D185 Test Methods for Coarse Particles in PigmentsD280 Test Methods for Hygroscopic Moisture(and OtherMatter Volatile Under the Test Conditions)in PigmentsD281 Test Method for Oil Absorption of Pigment
7、s bySpatula Rub-outD387 Test Method for Color and Strength of ChromaticPigments with a Mechanical MullerD1193 Specification for Reagent WaterD1648 Specification for Basic Lead Silicochromate PigmentD2371 Test Method for Pigment Content of Solvent-Reducible Paints3.Significance and Use3.1 These test
8、methods may be used to confirm the statedlead oxide,chromium trioxide and silica content of basic leadsilicochromate and is useful for quality control.4.Purity of Reagents4.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated,it is intended that all reagents shallconform t
9、o the specifications of the Committee on AnalyticalReagents of the American Chemical Society,where suchspecifications are available.3Other grades may be used,pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determ
10、ination.4.2 Unless otherwise indicated,references to water shall beunderstood to mean reagent water conforming to Type II ofSpecification D1193.5.Preparation of Sample5.1 Thoroughly mix liquid coatings and separate in accor-dance with Test Method D2371 sufficient pigment to enable therequired analys
11、es to be carried out.5.2 Thoroughly mix pigment supplied as such and grindseparated pigment to a fine powder in a mortar and pestlebefore taking portions for analysis.TOTAL LEAD AS LEAD OXIDE-GRAVIMETRICMETHOD6.Apparatus6.1 Glass Filtering Crucible(medium-porosity fritted disk),dried to constant wei
12、ght before use.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 January 2015.Originallyapproved
13、in 1961.Last previous edition approved in 2008 as D1844 86(2008).DOI:10.1520/D1844-86R14.2For 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 p
14、age onthe ASTM website.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 State
15、s 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 6.2 Platinum Dish.7.Reagents7.1 Acetic Acid(Glacial).7.2 Ammonium Hydroxide(sp gr 0.90)Concentrated
16、 am-monium hydroxide(NH4OH).7.3 Ammonium Acetate,Acid SolutionTo 300 mL of wateradd an equal volume of NH4OH.Neutralize with glacial aceticacid and add 20 mL in excess.7.4 Hydrochloric Acid(sp gr 1.19)Concentrated hydro-chloric acid(HCl).7.5 Hydrofluoric Acid(47%)Concentrated hydrofluoricacid(HF).7.6 Hydrogen Sulfide(H2S)Handle and use H2S in hood.7.7 Isopropyl Alcohol(50 and 98%).7.8 Nitric Acid(sp gr 1.42)Concentrated nitric acid(HNO3).7.9 Potassium Dichromate Solution(saturated)Prepare asatur
