1、Designation: F2853 10Standard 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、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 coatings, or substrates andhomogenous materials. The following material types weretested in the interlaboratory study for this standard t
4、est 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 Fluorescence (HDXRF) or MultipleMonochromatic Beam EDXRF (MMB-EDXRF).1.3 This test method is applicable for the products andmateria
5、ls 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 aninterlaboratory study using representative samples1.4 Ensure that the analysis area of the sample is visuallyuniform in appearan
6、ce 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. Metallic coatings are not covered by thistest method.1.6 X-ray NomenclatureThis standard names X-ray linesusing the IUPAC convent
7、ion 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 asstandard. No other units of measurement are included in thisstandard.1.9 This standard does not purport to address all of thesafety conc
8、erns, 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:2D883 Terminology Relating to PlasticsD6
9、299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Pre
10、cision of a Test MethodF2576 Terminology Relating to Declarable Substances inMaterials3. Terminology3.1 DefinitionsDefinitions of terms applying to XRF,plastics and declarable substances appear in TerminologyD883, E135, and F2576.3.2 Definitions of Terms Specific to This Standard:3.2.1 Compton scatt
11、eringthe inelastic scattering of anX-ray photon through its interaction with the bound electronsof an atom. This process is also referred to as incoherentscattering.3.2.2 fundamental parameters (FP) modela model forcalibration of X-ray fluorescence response, including the cor-rection of matrix effec
12、ts, 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 elemental composition as determined bythe technique in this test method is independent with respect tothe measured location on the
13、 specimen and among separatespecimens prepared from the same material.1This 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 approved July 1, 2010. Published July 20
14、10. DOI:10.1520/F285310.2For 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.1Copyright ASTM International, 100 Ba
15、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.4 low energy monochromatic beama focused mono-chromatic beam having its selected photon energy between 3and 9 keV.3.2.5 medium energy monochromatic beama focusedmonochromatic beam having its selected photon energy be-t
16、ween 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 selected energy.Method precision is achieved with a monochromatic beamhaving an energy bandwidth (Full Width Half Maximum) lessthan 61.5
17、% 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 excitation beamstwo ormore monochromatic beams.3.2.8 paint layera single paint layer or other similarsurface-coating material on a su
18、bstrate.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 as coherent scattering.3.2.10 substratethe material beneath a paint layer. Thesubstrate may or may not be homogenous.3.3 Acronyms:3.3
19、.1 EDXRFenergy dispersive X-ray fluorescence3.3.2 FPfundamental parameters3.3.3 HDXRFhigh definition X-ray fluorescence3.3.4 MMBmultiple monochromatic beams4. Summary of Test Method4.1 The relevant samples include paint layers, their sub-strates, and homogenous materials.4.2 This technique uses one
20、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 be analyzed is placed against an X-rayaperture. Depending on the data acquisition mode (see 13.1 and13.2), one or more monochromatic
21、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 mass fraction in the sample.4.3 The apparatus is calibrated for each data acquisitionmode. The calibration may be performed by the manu
22、factureror 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,childrens products, and other consumer products. Typical testtime for quantification of Pb in homogenous samples is 1 to 3min; and typi
23、cal test time for quantification of Pb in paint is 4to 8 min.6. Interferences6.1 Spectral InterferenceSpectral interferences resultfrom spectral overlaps among the X-ray lines that remainunresolved due to the limited energy resolution of the detector.For instance, the arsenic (As) K-L2,3(Ka1,2) peak
24、 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 affected. If the presence ofarsenic is suspected, the user may further investigate thearsenic interference. Interactions of photons an
25、d 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 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 i
26、n 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 by the contribution from thesubstrate, the uncertainty of the FP analysis can be significantand the Pb measurement for the paint laye
27、r 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 interelementeffects, exist among all elements as the result of absorption offluorescent X-rays (secondary X-rays) by atoms in the speci-men
28、. 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 sensitivityfor the second element. Mathematical methods may be used tocompensate for matrix effects. A number of mathematicalcorrection
29、 procedures are commonly utilized including full FPtreatments and mathematical models based on influence coef-ficient algorithms.TABLE 1 Mass Fraction Ranges for Various Sample TypesSample Type Homogenous Materialor Substrate TypeLead (Pb) Mass FractionRange, mg/kgUncoated Non-PVC Plastic,Glass or C
30、eramic141200Uncoated Metal 66600Uncoated PVC 3761150Paint Layer Plastic or Metal 30450Paint Layer Fabric 79200Paint Layer Wood 58F2853 1027. Apparatus7.1 EDXRF Spectrometer3designed for X-ray fluores-cence analysis using multiple monochromatic excitation beamswith an energy dispersive detector. Any
31、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 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
32、-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. Two or more X-ray optical elements arenecessary to provide multiple monochromatic beams. At leastone optical element provides a low en
33、ergy monochromaticbeam, and at least one optical element provides a mediumenergy monochromatic beam.7.1.3 X-Ray Detectorwith energy resolution$250 eV fullwidth at half maximum of the manganese (Mn) K-L2,3(Ka1,2)line.7.1.4 Digital Pulse Processor and Multi-channelAnalyzera digital pulse processor for
34、 pulse shaping andconditioning, and a multi-channel analyzer for binning thepulses according to X-ray energy.7.1.5 Detector Aperturean aperture 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 areopt
35、ional:7.2.1 Beam Shutterused to select a monochromatic beamor select a combination of monochromatic beams.7.2.2 Drift Correction Monitorsdue to instability of themeasurement system, the sensitivity and background of thespectrometer may drift with time. Drift correction monitorsmay be used to compens
36、ate for this drift. The optimum driftcorrection monitor samples are permanent materials that arestable with repeated exposure to X-rays.7.3 Discussionthe data acquisition has two modes, onefor homogenous materials and one for paint layers. Theuncoated mode only requires one monochromatic beam for th
37、eexcitation of the Pb L shell. The paint layer mode requires asecond and lower energy monochromatic beam with lesspenetration of the sample to determine paint surface informa-tion and the Pb mass fraction in the paint layer.8. Reagents and Materials8.1 Purity of Reagents4Reagent grade chemicals shal
38、l beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available. Other grades may be used,provided it is first ascertained that the reagent
39、is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination. Reagents used include materials used forcleaning 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
40、are recommended for han-dling reference materials and other samples to minimizecontamination.8.4 Appropriate personal protective equipment for the han-dling of reagents.8.5 Uncoated Mode Calibration StandardsAt least twostandards are required for calibration, one a scattering standard,and the other
41、a Pb-containing homogenous material (see Note3). The scattering standard shall have a known density,thickness, and composition. The other standard shall be a Pbcontaining homogenous standard with a known Pb massfraction. Refer to manufacturers recommendations.NOTE 1Better performance is expected if
42、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 Calibration StandardsA minimumof four standards are needed for calibration (see Note 3). Twostandards shall be scattering standards, and the other two shallbe
43、 Pb containing paint layer-on-substrate standards. Refer tomanufacturers recommendations.8.6.1 Scattering StandardsAt least two scattering stan-dards are necessary due to the overlap of Compton andRayleigh scattering of the low energy beam. One scatteringstandard shall have a known density, thicknes
44、s, and composi-tion. The other scattering standard shall be a thin paint layer,with a known mass per unit area, mounted on a thin polyesterfilm. 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-containingp
45、aint layer standards each with differing paint layer thicknessesand known Pb mass fraction are required.NOTE 2Better performance is expected if 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
46、standards may be used for improvedaccuracy.8.7 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 o
47、f the results, quality control(QC) samples are used for establishing and monitoring thestability and precision of an analytical measurement system3The sole source of supply of the apparatus known to the committee at this timeis X-Ray Optical Systems, Inc., 15 Tech Valley Drive, East Greenbush, NY 12
48、061.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 Chemicals, American Chemical Society Specifications, Am
49、ericanChemical 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 National Formulary, U.S. Pharmacopeia Convention, Inc. (USPC), Rockville,MD.F2853 103(see Section 17). If possible, the QC samples shall be repre-sentative of samples typically analyzed. The materials shall bestable under the anticipated storage conditions.9. Hazards9.1 Occupational Health and Saf
