1、Designation: F2853 101Standard Test Method forDetermination of Lead in Paint Layers and Similar Coatingsor in Substrates and Homogenous Materials by EnergyDispersive X-Ray Fluorescence Spectrometry Using MultipleMonochromatic Excitation Beams1This standard is issued under the fixed designation F2853
2、; 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
3、.1NOTESection 7.1.3 was changed editorially from “.$than 250 eV.” to correctly read “.equal to or better than 250 eV.”in July 2011.1. Scope1.1 This test method uses energy dispersive X-ray fluores-cence (EDXRF) spectrometry for detection and quantificationof lead (Pb) in paint layers, similar coatin
4、gs, or substrates andhomogenous materials. The following material types weretested in the interlaboratory study for this standard test method:ABS plastic, polyethylene, polypropylene, PVC, glass, zincalloy, wood, and fabric.1.2 This technique may also be commonly referred to asHigh Definition X-ray
5、Fluorescence (HDXRF) or MultipleMonochromatic Beam EDXRF (MMB-EDXRF).1.3 This test method is applicable for the products andmaterials described in 1.1 for a Pb mass fraction range of 14 to1200 mg/kg for uncoated samples and 30 to 450 mg/kg forcoated samples, as specified in Table 1 and determined by
6、 aninterlaboratory study using representative samples1.4 Ensure that the analysis area of the sample is visuallyuniform in appearance and at least as large as the X-rayexcitation beam at the point of sample excitation.1.5 For coating analysis, this test method is limited to paintand similar coatings
7、. Metallic coatings are not covered by thistest method.1.6 X-ray NomenclatureThis standard names X-ray linesusing the IUPAC convention with the Siegbahn convention inparentheses.1.7 There are no known ISO equivalent methods to thisstandard.1.8 The values stated in SI units are to be regarded asstand
8、ard. No other units of measurement are included in thisstandard.1.9 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 appli
9、ca-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceE135 Terminology Relating to A
10、nalytical Chemistry forMetals, Ores, and Related MaterialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF2576 Terminology Relating to Declarable Substances inMaterials3. Terminology3.1 DefinitionsDefinitions of terms applying to XRF,plastics and decl
11、arable substances appear in TerminologyD883, E135, and F2576.3.2 Definitions of Terms Specific to This Standard:3.2.1 Compton scatteringthe inelastic scattering of anX-ray photon through its interaction with the bound electronsof an atom. This process is also referred to as incoherentscattering.3.2.
12、2 fundamental parameters (FP) modela model forcalibration of X-ray fluorescence response, including the cor-rection of matrix effects, based on the theory describing thephysical processes of the interactions of X-rays with matter.3.2.3 homogenous materialmaterials are considered ho-mogenous when the
13、 elemental composition as determined bythe technique in this test method is independent with respect to1This test method is under the jurisdiction of ASTM Committee F40 onDeclarable Substances in Materials and is the direct responsibility of SubcommitteeF40.01 on Test Methods.Current edition approve
14、d July 1, 2010. Published July 2010. DOI:10.1520/F28531001.2For 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.1C
15、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the measured location on the specimen and among separatespecimens prepared from the same material.3.2.4 low energy monochromatic beama focused mono-chromatic beam having its selected phot
16、on energy between 3and 9 keV.3.2.5 medium energy monochromatic beama focusedmonochromatic beam having its selected photon energy be-tween 15 and 23 keV.3.2.6 monochromatic beaman incident monochromaticbeam on a sample having a selected photon energy with anarrow energy bandwidth relative to the sele
17、cted energy.Method precision is achieved with a monochromatic beamhaving an energy bandwidth (Full Width Half Maximum) lessthan 61.5 % relative to the selected energy and containingmore than 98 % flux of the spectrum of the excitation beamwhich is incident on the sample.3.2.7 multiple monochromatic
18、excitation beamstwo ormore monochromatic beams.3.2.8 paint layera single paint layer or other similarsurface-coating material on a substrate.3.2.9 Rayleigh scatteringthe elastic scattering of an X-rayphoton through its interaction with the bound electrons of anatom. This process is also referred to
19、as coherent scattering.3.2.10 substratethe material beneath a paint layer. Thesubstrate may or may not be homogenous.3.3 Acronyms:3.3.1 EDXRFenergy dispersive X-ray fluorescence3.3.2 FPfundamental parameters3.3.3 HDXRFhigh definition X-ray fluorescence3.3.4 MMBmultiple monochromatic beams4. Summary
20、of Test Method4.1 The relevant samples include paint layers, their sub-strates, and homogenous materials.4.2 This technique uses one or more monochromatic exci-tation beams to separately quantify the Pb mass fractions inpaint layers and substrates, and homogenous materials. Thearea of the sample to
21、be analyzed is placed against an X-rayaperture. Depending on the data acquisition mode (see 13.1 and13.2), one or more monochromatic X-ray beams are focused onthe sample. The appropriate region of the fluorescence spec-trum is processed by an FPmethod to obtain the analysis result,that is, the Pb ma
22、ss fraction in the sample.4.3 The apparatus is calibrated for each data acquisitionmode. The calibration may be performed by the manufactureror by the user.5. Significance and Use5.1 This test method may be used for quantitative determi-nations of Pb in painted and unpainted articles such as toys,ch
23、ildrens products, and other consumer products. Typical testtime for quantification of Pb in homogenous samples is 1 to 3min; and typical test time for quantification of Pb in paint is 4to 8 min.6. Interferences6.1 Spectral InterferenceSpectral interferences resultfrom spectral overlaps among the X-r
24、ay lines that remainunresolved due to the limited energy resolution of the detector.For instance, the arsenic (As) K-L2,3(Ka1,2) peak directlyoverlaps the Pb L3-M4,5(La1,2) peak. The arsenic-Pb interfer-ence may be minimized by a de-convolution algorithm, but theprecision of the Pb analysis may be a
25、ffected. If the presence ofarsenic is suspected, the user may further investigate thearsenic interference. Interactions of photons and electronsinside the detector result in additional peaks in the spectrumknown as escape peaks and sum peaks. These peaks canoverlap with X-ray lines of interest, for
26、example, the sum peakof iron (Fe) K-L2,3(Ka1,2) can overlap with the Pb L2-M4(Lb1)peak.6.2 Substrate InterferenceThe presence of Pb in a sub-strate can interfere with the determination of the Pb massfraction of the paint layer. If the Pb signal of the paint layer andsubstrate composite is dominated
27、by the contribution from thesubstrate, the uncertainty of the FP analysis can be significantand the Pb measurement for the paint layer will exhibit apositive bias and may not meet the precision statement of thistest method. See Note 8 in Section 16.6.3 Matrix EffectMatrix effects, also called intere
28、lementeffects, exist among all elements as the result of absorption offluorescent X-rays (secondary X-rays) by atoms in the speci-men. Absorption reduces the apparent sensitivity for theelement. In contrast, the atom that absorbs the X-rays may inturn emit a fluorescent X-ray, increasing apparent se
29、nsitivityfor the second element. Mathematical methods may be used tocompensate for matrix effects. A number of mathematicalTABLE 1 Mass Fraction Ranges for Various Sample TypesSample Type Homogenous Materialor Substrate TypeLead (Pb) Mass FractionRange, mg/kgUncoated Non-PVC Plastic,Glass or Ceramic
30、141200Uncoated Metal 66600Uncoated PVC 3761150Paint Layer Plastic or Metal 30450Paint Layer Fabric 79200Paint Layer Wood 58F2853 1012correction procedures are commonly utilized including full FPtreatments and mathematical models based on influence coef-ficient algorithms.7. Apparatus7.1 EDXRF Spectr
31、ometer3designed for X-ray fluores-cence analysis using multiple monochromatic excitation beamswith an energy dispersive detector. Any EDXRF spectrometermay be used if it is capable of meeting method precision andits design incorporates the following features:7.1.1 Source of X-ray Excitationtypically
32、 an X-ray tube,capable of exciting the Pb L lines in a sample. For instance, anX-ray tube with a zirconium, molybdenum, rhodium, palla-dium, or silver target can be used.7.1.2 X-ray OpticsX-ray optical elements capable of ac-cepting X-rays from a tube and directing monochromaticbeams on the sample.
33、Two or more X-ray optical elements arenecessary to provide multiple monochromatic beams. At leastone optical element provides a low energy monochromaticbeam, and at least one optical element provides a mediumenergy monochromatic beam.7.1.3 X-Ray Detectorwith energy resolution equal to orbetter than
34、250 eV full width at half maximum of themanganese (Mn) K-L2,3(Ka1,2) line.7.1.4 Digital Pulse Processor and Multi-channelAnalyzera digital pulse processor for pulse shaping andconditioning, and a multi-channel analyzer for binning thepulses according to X-ray energy.7.1.5 Detector Aperturean apertur
35、e in the beam pathbetween the sample and the detector to limit the field of viewof the detector.7.2 The following spectrometer features and accessories areoptional:7.2.1 Beam Shutterused to select a monochromatic beamor select a combination of monochromatic beams.7.2.2 Drift Correction Monitorsdue t
36、o instability of themeasurement system, the sensitivity and background of thespectrometer may drift with time. Drift correction monitorsmay be used to compensate for this drift. The optimum driftcorrection monitor samples are permanent materials that arestable with repeated exposure to X-rays.7.3 Di
37、scussionthe data acquisition has two modes, onefor homogenous materials and one for paint layers. Theuncoated mode only requires one monochromatic beam for theexcitation of the Pb L shell. The paint layer mode requires asecond and lower energy monochromatic beam with lesspenetration of the sample to
38、 determine paint surface informa-tion and the Pb mass fraction in the paint layer.8. Reagents and Materials8.1 Purity of Reagents4Reagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical
39、 Reagents of the American Chemical Society wheresuch specifications are available. Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination. Reagents used include materials used forcl
40、eaning of samples.8.2 Reagents:8.2.1 Isopropanol or ethanol,8.2.2 Nitric acid (HNO3),8.2.3 Hexane, and8.2.4 Deionized water (H2O).8.3 GlovesDisposable gloves are recommended for han-dling reference materials and other samples to minimizecontamination.8.4 Appropriate personal protective equipment for
41、 the han-dling of reagents.8.5 Uncoated Mode Calibration StandardsAt least twostandards are required for calibration, one a scattering standard,and the other a Pb-containing homogenous material (see Note3). The scattering standard shall have a known density,thickness, and composition. The other stan
42、dard shall be a Pbcontaining homogenous standard with a known Pb massfraction. Refer to manufacturers recommendations.NOTE 1Better performance is expected if the Pb mass fraction of thePb containing calibration standard is within the upper half of the scoperange (see Section 1).8.6 Paint Layer Mode
43、Calibration StandardsA minimumof four standards are needed for calibration (see Note 3). Twostandards shall be scattering standards, and the other two shallbe Pb containing paint layer-on-substrate standards. Refer tomanufacturers recommendations.8.6.1 Scattering StandardsAt least two scattering sta
44、n-dards are necessary due to the overlap of Compton andRayleigh scattering of the low energy beam. One scatteringstandard shall have a known density, thickness, and composi-tion. The other scattering standard shall be a thin paint layer,with a known mass per unit area, mounted on a thin polyesterfil
45、m. An example of the polyester film is film used for liquidcells having a thickness of 3.7 m or similar.8.6.2 Paint Layer StandardsAt least two Pb-containingpaint layer standards each with differing paint layer thicknessesand known Pb mass fraction are required.NOTE 2Better performance is expected i
46、f the Pb mass fraction of thetwo Pb containing paint layer standards are within the upper half of thescope range (see Section 1).NOTE 3Additional calibration standards may be used for improvedaccuracy.3The sole source of supply of the apparatus known to the committee at this timeis X-Ray Optical Sys
47、tems, Inc., 15 Tech Valley Drive, East Greenbush, NY 12061.If you are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.4Reagent
48、Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, D.C. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Annular Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand N
49、ational Formulary, U.S. Pharmacopeia Convention, Inc. (USPC), Rockville,MD.F2853 10138.7 Reference Materials:8.7.1 Homogeneous reference materials are available fromcommercial sources. At the time of this publication, there areno commercially available paint layer reference materials.8.8 Quality Control Samples:8.8.1 To ensure the quality of the results, quality control(QC) samples are used for establishing and monitoring thestability and precision of an analytical measurement system(see Section 17). If possible, the QC samples sh
