ASTM_D_5381_-_93_2014.pdf

Designation:D538193(Reapproved 2014)Standard Guide forX-Ray Fluorescence(XRF)Spectroscopy of Pigments andExtenders1This standard is issued under the fixed designation D5381;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 guide covers the general considerations for properuse of X-ray fluorescence(XRF)spectroscopy.Because manydifferences exist between XRF instruments,no detailed oper-ating instructions are provided.The analyst should follow theinstructions provided by the manufacturer for his instrument.1.2 The analyst is encouraged to consult the chemicalliterature,varioustradejournals,pigmentsupplierpublications,etc.,as well as the instrument manuals from themanufacturer.1.3 XRF is commonly employed to determine the elementspresent in inorganic pigments and extenders,often in concertwith other analysis techniques.Organic pigments cannot nor-mally be identified solely by XRF.On occasion,organicpigments contain heavier elements that can distinguish be-tween major classes of these pigments or may serve todistinguish one of the two distinct pigments.However,theanalyst should be wary of a qualitative pigment identificationsolely by XRF technique.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 health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazardinformation see Section 3 on Radiation Concerns.2.Referenced Documents2.1 ASTM Standards:2D3925 Practice for Sampling Liquid Paints and RelatedPigmented Coatings3.Radiation Concerns3.1 Modern XRF instrumentation has been designed tominimize exposure of laboratory personnel to X-ray radiationduring instrument use.However,most laboratories use dosim-etry to monitor personnel who are normally present around theXRF instrument while it is in operation.Such dosimetrydevices are normally read on a monthly basis.3.2 After XRF instrument maintenance(especially wherethe X-ray tube,detector,or shielding has been moved orreplaced),an X-ray survey of all areas around the instrument(while in operation)is recommended.The results of such asurvey should be documented and stored for future reference.3.3 It is recommended that the laboratory check its compli-ance with all applicable local,state,and federal requirements.Many companies also have policies concerning use of X-rayequipment in their laboratories.3.4 It is common laboratory practice to post placards on allentrances to the laboratories containing X-ray equipment thatindicate its presence.4.Summary of the Guide4.1 A general guide for qualitative elemental analysis ofpaint and paint components is provided.Knowledge of theelements present in a sample can be used to infer the identityof pigments and extenders that may be present.The absence ofspecific pigments and extenders can be proven by the absenceof their constituent elements.The presence or absence of toxicelements can be demonstrated.Analysis consists of irradiatingthe test specimen with monochromatic X-rays and determiningthe energy or wavelength of the fluorescent X-ray emitted bythe specimen.Since different elements emit X-rays withdifferent energy and wavelength under these conditions,theelement content of the specimen can be determined by exami-nation of the X-ray spectrum.The spectrum is recorded eitheron chart paper or magnetic media.Identification of the con-stituent elements is accomplished by comparing the peaks inthe spectrum with known tabulated data,using either manual orcomputer-assisted procedures.5.Significance and Use5.1 The identification of pigments in a sample of liquidpaint or paint film is often important for regulatory purposes.1This guide is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved July 1,2014.Published July 2014.Originally approvedin 1993.Last previous edition approved in 2009 as D5381 93(2009).DOI:10.1520/D5381-93R014.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Many inorganic pigments or extenders utilized in past paintformulation are now regulated by federal,state,or municipalhealth authorities.XRF is one of the more common andconvenient methods employed to characterize the pigmentcomposition of a paint formulation.5.2