1、Designation: F2980 13Standard Test Method forAnalysis of Heavy Metals in Glass by Field Portable X-RayFluorescence (XRF)1This standard is issued under the fixed designation F2980; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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 field portable X-ray fluores-cence (XRF) spectrometric procedures for analyses of ars
3、enicand lead in glass compositions using field portable energydispersive XRF spectrometers.1.2 The mass fraction range of arsenic within which this testmethod is quantitative is given in Table 1. Scope limits weredetermined from the interlaboratory study results using theapproach given in Practice E
4、1601.1.3 The mass fraction range for which lead was tested isgiven in Table 1. However, lead results cannot be consideredquantitative on the basis of single-sample results because theprecision performance is not good enough to allow laboratoriesto compare results in a quantitative manner.NOTE 1The p
5、erformance of this test method was evaluated usingresults based on single-sample determinations from specimens composedof glass beads. One laboratory has determined that performance can besignificantly improved by basing reported results on the mean of deter-minations from multiple samples to overco
6、me inherent heterogeneity ofelements in glass beads, especially the element lead. Additional informa-tion is provided in Section 17 on Precision and Bias.1.3.1 To obtain quantitative performance, lead results mustconsist of the average of four or more determinations.1.4 The values stated in SI units
7、 are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 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 practi
8、ces and determine the applica-bility of regulatory limitations prior to use. Some specifichazards statements are given in Section 7 on Hazards.2. Referenced Documents2.1 ASTM Standards:2D75/D75M Practice for Sampling AggregatesD6299 Practice for Applying Statistical Quality Assuranceand Control Char
9、ting Techniques to Evaluate AnalyticalMeasurement System PerformanceE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE177 Practice for Use of the Terms Precision a
10、nd Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric AnalysisE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytic
11、al MethodE1621 Guide for X-Ray Emission Spectrometric AnalysisF2576 Terminology Relating to Declarable Substances inMaterials2.2 ANSI Standard:3N43.2 Radiation Safety for X-Ray Diffraction and Fluores-cence Analysis Equipment2.3 AASHTO Standard:4TP-97-11 Test Method for Glass Beads used in PavementM
12、arkings3. Terminology3.1 DefinitionsDefinitions of terms applying to X-rayfluorescence (XRF) and declarable substances appear in Ter-minologies E135 and F2576, respectively.1This test method is under the jurisdiction of ASTM Committee on DeclarableSubstances in Materials and is the direct responsibi
13、lity of Subcommittee F40.01 onTest Methods.Current edition approved Feb. 15, 2013. Published March 2013. DOI: 10.1520/F2980-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information
14、, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol
15、St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2 Compton-matrix correction, nmeasured intensity ofCompton or incoherent scattered radiation may be used directlyt
16、o compensate for matrix effects or indirectly for the determi-nation of the effective mass absorption coefficient to correct formatrix effects.53.2.1 DiscussionThe compensation for matrix effects isbased on a combination of sample preparation and experimen-tal intensity data.3.3 Compton scatter, nin
17、elastic scattering of an X-rayphoton through its interaction with the bound electrons of anatom.3.3.1 DiscussionThis process is also referred to as inco-herent scatter.3.4 fundamental parameters, FP, model, nmodel for cali-bration of X-ray fluorescence response, including the correc-tion of matrix e
18、ffects, based on the theory describing thephysical processes of the interactions of X-rays with matter.63.5 Acronyms:3.5.1 EDXRFEnergy dispersive X-ray fluorescence3.5.2 QCQuality control3.5.3 XRFX-ray fluorescence4. Summary of Test Method4.1 Portable handheld instruments are used to measure glasssp
19、heres, ground glass, cullet, fiberglass, and sheet glass fortheir contents of arsenic and lead. Samples of sheet glass canbe measured directly. Samples that are not in sheet form aremeasured as is or after pulverizing to an appropriate particlesize.4.2 The samples of glass spheres or powders may be
20、placedinto disposable cups with a polymer film supporting the glass.The filled cup is measured from below through the polymerfilm.4.3 The glass specimen may be analyzed in situ by using ahandheld spectrometer positioned in contact with sheet glass orthe contents of a larger container, for example, a
21、 bulk shippingcontainer.4.4 The handheld XRF may be used while the operator isholding the unit or by being mounted in a stand for safer, moreconvenient laboratory use. The two measurement options arediscussed throughout this test method.5. Significance and Use5.1 Waste glass is currently recycled in
22、to various consumerproducts. This test method has been developed as a tool forevaluation of heavy metals in glass to satisfy reporting require-ments for maximum allowable content for some applications.5.2 The ranges within which this test method is quantitativeare given in Table 1.5.3 For amounts of
23、 the analyte elements outside the rangesin Table 1, this test method provides screening results. That is,it provides an unambiguous indication that each element can bedescribed as present in an amount greater than the scope upperlimit or that the amount of the element can be described as lessthan th
24、e scope lower limit with a high degree of confidence.NOTE 2In general, when a quantitative result is obtained, the analystcan make a clear decision as to whether a material is suitable for theintended purpose. When the contents of elements of interest are outsidethe quantitative range, the analyst c
25、an still make a decision whether theamount is too high or whether additional analyses are required.5.4 These methods can be applied to glass beads, plateglass, float glass, fiber glass, or ground glass. This test methodhas been validated for the ranges of matrix compositions thatare summarized in Ta
26、ble 2.5.5 Detection limits, sensitivity, and element ranges willvary with matrices, detector type, and other instrument condi-tions and parameters.5.6 All analytes are determined as the element and reportedas such. These include all elements listed in Table 1. This testmethod may be applicable to ot
27、her glass matrices, additionalelements, and wider concentration ranges provided the labora-tory is able to validate the broadened scope of this test method.6. Interferences6.1 Spectral InterferencesThese can occur for some ele-ments as a result of partial or total line overlaps. These lineoverlaps c
28、an result from scattered characteristic lines from thetarget of the X-ray tube or by X-ray fluorescence from atoms inthe specimen. Spectral interference can also be the result ofescape peaks from the solid-state detector. See Guide E1621for a full discussion of models used to correct for these effec
29、ts.In this particular case, the most obvious line overlap is theoverlap of As K-L2,3(As K1,2; 10.53 keV) on Pb L3-M5(PbL1; 10.55 keV) and vice versa. The energy difference betweenthese two lines is about 0.02 keV, which cannot be resolvedwith the detectors used. The emission lines of these twoelemen
30、ts will appear as a single peak. However, both As andPb have alternative lines that can be used for analysis. For Pb,the use of the doublet Pb L2,3-M4,N5(Pb L1,2; 12.61 keV) ishighly recommended. This line has virtually the same sensi-tivity as the Pb L3-M5line. For As, the As K-M2,3(As K1,3;11.72 k
31、eV) can be used; its sensitivity is about 20 % of themore intense As K-L2,3line. It is possible to determine the netintensity of Pb L3-M5based on the intensity of Pb L2,3-M4,N5(this implies determining a proportionality factor between the5Andermann, G. and Kemp, J. W., “Scattered X-rays as Internal
32、Standards inX-Ray Spectroscopy,” Analytical Chemistry, Vol 20, No. 8, 1958.6The algorithm used for the procedure is usually implemented in the instrumentmanufacturers software. Third-party software is available and may be used.TABLE 1 Scope Ranges for Quantitative ResultsElement Scope Lower Limit (m
33、g/kg)Scope Upper Limit (mg/kg)Arsenic 240 2000Lead 120 500TABLE 2 Matrix Components and RangesOxide Scope Lower Limit, % Scope Upper Limit, %SiO258 80Al2O3110Na2O3 15CaO 6 20MgO 1 5F2980 132two lines on specimens with no or varying amounts of As).This can then be used to calculate the intensity of A
34、s K-L2,3.6.2 In EDXRF, the possibility exists that two photons areseen and treated as a single one by the counting electronics.When that happens, they appear as a single photon with anenergy corresponding to the sum of the energies of theindividual photons. This phenomenon is called the sum-peak.For
35、 this effect to be significant, the total count rate must behigh; and (at least) one element must be present at a relativelyhigh level; and the element concerned must have a high yield.In the current method, the presence of e.g. iron at high levelscould lead to a sum-peak of 2 Fe K-L3 (6.4 keV) phot
36、ons, withan energy of about 12.6- 12.8 keV - this corresponds to theenergy of Pb L2,3-M4,N5. The software provided by themanufacturer must correct for this effect; otherwise the inten-sity (and thus the contents) of Pb L2,3-M4,N5is overestimated.6.3 Matrix InterferencesSome of the X-rays generatedwi
37、thin the sample will interact with atoms in the matrix. As aresult of such interactions, the emitted intensity of the analytedepends on the amount of the analyte in the sample and, to alesser, but measurable degree, on the amounts of other ele-ments. The magnitude of such matrix interferences is mos
38、tpronounced for elements that are present in high concentra-tions. Several mathematical models, such as the fundamentalparameter model, exist for the correction of such effects; seeGuide E1361 for a full discussion. Typically, these matrixcorrection models require that the net intensities are free f
39、romline overlap effects. In practice, the approach chosen dependsupon the manufacturer.6.4 Float glass is heterogeneous because one side is coatedwith tin. Differential absorption can bias the results.7. Apparatus7.1 EDXRF Spectrometerdesigned for X-ray fluorescenceanalysis with energy dispersive se
40、lection of radiation. AnyEDXRF spectrometer can be used if its design incorporates thefollowing features.7.1.1 Source of X-Ray Excitationcapable of exciting therecommended lines, typically an X-ray tube. The recom-mended lines are shown in Table 3.7.1.2 X-Ray DetectorAn energy resolution of better t
41、han250 eV at Mn K-L2,3has been found suitable for use in this testmethod.7.1.3 Signal conditioning and data-handling electronics in-clude the functions of X-ray counting and peak processing.7.2 The following spectrometer features and accessories areoptional.7.2.1 Beam Filtersused to make the excitat
42、ion moreselective and reduce background count rates.7.2.2 Drift Correction Monitor(s)Because of instability ofthe measurement system, the sensitivity and background of thespectrometer may drift with time. Drift correction monitorsmay be used to correct for this drift. The optimum driftcorrection mon
43、itor specimens are permanent materials that arestable with time and repeated exposure to X-rays.7.3 Reference Materials:7.3.1 Purchased certified reference materials, and7.3.2 In-house reference materials that were analyzed by atleast two independent methods.7.4 Consumables:7.4.1 Disposable latex or
44、 nitrile gloves,7.4.2 Methanol or isopropyl alcohol,7.4.3 Deionized water,7.4.4 XRF sample cups,7.4.5 Lint-free wipes, and7.4.6 Polymer film, including, but not limited to polyimide,polyester, and polypropylene.8. Hazards8.1 Safety practices shall conform to applicable local, state,and national regu
45、lations. For example, personal monitoringdevices and periodic radiation surveys may be required.8.2 Dust MaskWhen this test method is performed onpowder samples, it may be advisable to use a dust mask.8.3 GlovesThe use of powder-free polymer gloves isrecommended to prevent contamination of sample su
46、rfaces bybody oils and other substances.9. Sampling9.1 Users should develop plans to determine if the measuredspecimens are representative of a larger quantity of material.Refer to AASHTO TP-97-11 or Practice D75/D75M forexamples of sampling procedures for quantities greater than 45kg.9.2 For labora
47、tories having small quantities of material,three replicate measurements may be taken to obtain informa-tion on homogeneity. If the range of three results is greater thanthe repeatability limit of this standard test method, there maybe evidence for statistically significant heterogeneity. Theanalyst
48、may measure more samples and note standard devia-tion.10. Preparation of Test Specimens10.1 Treat reference materials and test specimens for eachmethod exactly the same way to ensure reproducible results.Samples may be analyzed with little sample preparation, ifcalibration standards and specimens ar
49、e in the same form.10.2 Loose BeadsFor loose beads, simply place them insample cups with polymer film. Samples and standards shouldbe of comparable particle size for presentation to the spectrom-eter. The cup should be filled to a depth greater than 6 mm toachieve infinite thickness for arsenic and lead. The sample cupis placed in the measurement position of the EDXRF instru-ment for measurement.TABLE 3 Analytical Lines for Analysis of Arsenic and LeadAnalyteArsenic LeadPreferred Line As K-L2,3(As K1,2; at 10.53 keV)Pb L2,3M4,N5(Pb L1,2; at 12.61 keV)Sec
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