ASTM_D_970_-_86_1999.pdf

Designation:D 970 86(Reapproved 1999)Standard Test Methods forPara Red and Toluidine Red Pigments1This standard is issued under the fixed designation D 970;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 parentheses indicates the year of last reapproval.Asuperscript epsilon(e)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 para red and toluidine redpigments(toners)in the dry form commercially known as“pure.”1.2 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 health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 185 Test Methods for Coarse Particles in Pigments,Pastes,and Paints2D 280 Test Methods for Hygroscopic Moisture(and OtherMatter Volatile Under the Test Conditions)in Pigments2D 387 Test Method for Color and Strength of Color Pig-ments with a Mechanical Muller3D 1193 Specification for Reagent Water4D 3335 Test Method for Low Concentrations of Lead,Cadmium,and Cobalt in Paint by Atomic AbsorptionSpectroscopy3D 3624 Test Method for Low Concentrations of Mercury inPaint by Atomic Absorption Spectroscopy33.Significance and Use3.1 These test methods are used to determine the purity andsome physical properties of para red and toluidine red pig-ments.This information is significant to pigment producers andto coatings manufacturers.4.Reagents4.1 Purity of ReagentsReagent grade chemicals shall 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 reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.4.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean water conforming to TypeII of Specification D 1193.4.3 Chloroform.4.4 Hydrochloric Acid(1+1)Mix equal volumes of con-centrated hydrochloric acid(HCl,sp gr 1.19)and water.4.5 Nitric Acid(3+5)Mix 3 volumes of concentratednitric acid(HNO3,sp gr 1.42)with 5 volumes of water.4.6 Potassium Hydroxide,Alcoholic SolutionDissolve 10g of potassium hydroxide(KOH)in 90 mL of ethyl alcohol(95%).4.7 Sodium Hydroxide(100 g/L)Dissolve 100 g of so-dium hydroxide(NaOH)in water and dilute to 1 L.5.Solubility in Chloroform5.1 Place about 0.05 g of the dry pigment in a 50-mLNessler tube,add 40 mL of chloroform,and warm slightly,stirring with a glass rod.Compare this solution with a similarlyprepared solution of a standard sample of known purity.Complete solubility of the pigment in chloroform is indicatedif a clear orange red solution is obtained.NOTE1Any turbidity indicating an impurity may be separated con-veniently by extracting 5 g of the pigment in a soxhlet extractor,usingchloroform as the solvent.The residue may then be examined andestimated.6.Qualitative Test for Identity and Purity6.1 To 10 mL of the chloroform solution(5.1)add 2 mL ofalcoholic potassium hydroxide(KOH)solution.An intenseviolet coloration indicates the presence of para red toner,(1-(p-nitro-phenylazo)-2-naphthol).A wine red coloration indi-cates the presence of toluidine red toner(1-(2-nitro-p-tolyl-azo)-2-naphthol).It is well to make side-by-side comparisons,using a standard pigment as control.1These test methods are under the jurisdiction ofASTM Committee D-1 on Paintand Related Coatings,Materials,and Applications and are the direct responsibilityof Subcommittee D01.31 on Pigment Specifications.Current edition approved Sept.26,1986.Published November 1986.Originallypublished as D 970 48.Last previous edition D 970 73(1979)e1.2Annual Book of ASTM Standards,Vol 06.03.3Annual Book of ASTM Standards,Vol 06.01.4Annual Book of ASTM Standards,Vol 11.01.5Reagent 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 LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTE2Infrared spectrophotometry may also be employed for thispurpose if equipment is available and suitable reference spectra have beenagreed upon by purchaser and seller.7.Ash7.1 Transfer about 2 g of the sample(weighed to 0.1 mg)toa tared porcelain or platinum crucible and he