ASTM_D_4764_-_01_2012.pdf

Designation:D476401(Reapproved 2012)Standard Test Method forDetermination by X-ray Fluorescence Spectroscopy ofTitanium Dioxide Content in Paint1This standard is issued under the fixed designation D4764;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of titaniumdioxide content in liquid paint.This test method is applicableto both water-reducible and solvent-reducible paints.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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.Specific hazardsstatements are given in Section 7.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1394 Test Methods for Chemical Analysis of White Tita-nium PigmentsD2369 Test Method for Volatile Content of CoatingsD3925 Practice for Sampling Liquid Paints and RelatedPigmented CoatingsD3980 Practice for Interlaboratory Testing of Paint andRelated Materials(Withdrawn 1998)3E180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)33.Summary of Test Method3.1 Paint containing a known amount of titanium dioxide isused as the reference standard.A solution of tetraethylammo-nium bromide in 2-ethoxyethanol is added to the standard paintand to each paint being analyzed.Drawdown films of thestandard and test paint are made on thin plastic sheets.Theintensities of key X-ray fluorescence peaks of titanium andbromine are measured.The titanium dioxide content is deter-mined by comparing the ratio of the intensities of titanium andbromine peaks in the test paint and the standard.Differences inthe nonvolatile content of the paints are taken into account inthe calculation of results.4.Significance and Use4.1 Titanium dioxide pigments are components with highrefractive index that significantly influence the opacity,color,durability,and other properties of coatings.This test methodfor determining titanium dioxide content is quicker and easierto use than Test Methods D1394,a wet chemical analysismethod for pigments.It is conveniently applicable to singlesamples and to large numbers of samples.Only a singlerelatively stable reagent used to prepare standards and paintsunder test need be stored.Drawdown specimens used asstandards,once prepared,can be stored indefinitely and usedrepeatedly.5.Apparatus5.1 X-ray Fluorescence Spectrometer,suitable for measure-ment of the baseline corrected intensity of the K lines oftitanium and of bromine.For spectrometers equipped with atungsten or chromium target and a lithium fluoride(200)analyzing crystal,these lines are observed at 2 angles of86.09 and 29.97,respectively.NOTE1Follow the recommendations of the manufacturer of theinstrument used.Use operating conditions that ensure that the count ratefor bromine and titanium are within the linear response range of thedetector.Although the base operating conditions and count rate may bedifferent for different instruments,these differences will not affect theoutcome of the analysis.5.2 Paint Shaker.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1,2012.Published July 2012.Originally approvedin 1988.Last previous edition approved in 2006 as D4764 01(2006).DOI:10.1520/D4764-01R12.2For 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 page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.3 Film Applicator,to produce a 75-m(3-mil)wet filmthickness.5.4 Plastic Sheet,4with no interfering X-ray fluorescencepeaks and not attacked by paint solvent.5.5 Perforated Suction Plate,or other flat surface.5.6 Vials and caps,20 mL.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests,unless otherwise specified.It is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.5Other grades may be used,provided it is first ascertained that the