ASTM F2617-15(2023)

Standard Test Method for Identification and Quantification of Chromium, Bromine, Cadmium, Mercury, and Lead in Polymeric Material Using Energy Dispersive X-ray Spectrometry

SIGNIFICANCE AND USE
5.1 This test method is intended for the determination of chromium, bromine, cadmium, mercury, and lead, in homogeneous polymeric materials. The test method may be used to ascertain the conformance of the product under test to manufacturing specifications. Typical time for a measurement is 5 to 10 min per specimen, depending on the specimen matrix and the capabilities of the EDXRF spectrometer.
SCOPE
1.1 This test method describes an energy dispersive X-ray fluorescence (EDXRF) spectrometric procedure for identification and quantification of chromium, bromine, cadmium, mercury, and lead in polymeric materials.  
1.2 This test method is not applicable to determine total concentrations of polybrominated biphenyls (PBB), polybrominated diphenyl ethers (PBDE) or hexavalent chromium. This test method cannot be used to determine the valence states of atoms or ions.  
1.3 This test method is applicable for a range from 20 mg/kg to approximately 1 wt % for chromium, bromine, cadmium, mercury, and lead in polymeric materials.  
1.4 This test method is applicable for homogeneous polymeric material.  
1.5 The values stated in SI units are to be regarded as the standard. Values given in parentheses are for information only.  
1.6 This test method is not applicable to quantitative determinations for specimens with one or more surface coatings present on the analyzed surface; however, qualitative information may be obtained. In addition, specimens less than infinitely thick for the measured X rays, must not be coated on the reverse side or mounted on a substrate.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2023
• ICS: 71.040.50 - Physicochemical methods of analysis
• ICS: 83.080.01 - Plastics in general
• Technical Committee: F40 - Declarable Substances in Materials
• Drafting Committee: F40.01 - Test Methods

Relations

• Replaces: ASTM F2617-15 - Standard Test Method for Identification and Quantification of Chromium, Bromine, Cadmium, Mercury, and Lead in Polymeric Material Using Energy Dispersive X-ray Spectrometry
• Effective Date: 01-Oct-2023
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D6299-23a - Standard Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
• Effective Date: 01-Dec-2023
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D6299-23e1 - Standard Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
• Effective Date: 01-Jul-2023
• Refers: ASTM D883-22 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2022
• Refers: ASTM F2576-15a - Standard Terminology Relating to Declarable Substances in Materials (Withdrawn 2024)
• Effective Date: 01-Aug-2015

Overview

ASTM F2617-15(2023) is the internationally recognized standard test method for the identification and quantification of hazardous elements-chromium, bromine, cadmium, mercury, and lead-in homogeneous polymeric materials using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometry. Developed by ASTM, this standard enables manufacturers, regulatory bodies, and laboratories to efficiently ensure compliance with product safety and environmental regulations concerning polymeric materials.

EDXRF provides rapid, non-destructive testing-typically 5 to 10 minutes per sample-to help ascertain whether polymeric materials meet strict manufacturing specifications and legislative limits for restricted substances. This document aligns with globally recognized standardization principles including those set forth by the World Trade Organization’s Technical Barriers to Trade (WTO TBT) Committee.

Key Topics

• Target Elements: The standard applies specifically to chromium, bromine, cadmium, mercury, and lead present in homogeneous polymeric matrices.
• Scope and Limitations:
  • Quantitative detection ranges from 20 mg/kg to approximately 1 wt% for each element.
  • Not suitable for monitoring total polybrominated biphenyls (PBB), polybrominated diphenyl ethers (PBDE), or hexavalent chromium, nor for determining valence states.
  • Applicable only to homogeneous polymeric materials-samples with surface coatings or laminates might only yield qualitative results.
• Sample Requirements:
  • Specimens should be flat, smooth, and of sufficient thickness (typically ≥2 mm) to ensure measurement accuracy.
• Calibration and Quality Control:
  • Reliable calibration relies on certified reference materials and established calibration models (empirical or fundamental parameters).
  • Repeated verification and use of quality control samples ensure ongoing accuracy and precision.
• Interferences and Corrections:
  • Matrix and interelement effects must be accounted for, as substances like chlorine, zinc, or tin can affect sensitivity.
  • Instrument drift and spectral overlaps require monitoring and correction using drift monitors and appropriate software automation.

Applications

ASTM F2617-15(2023) finds widespread practical use in several sectors:

• Regulatory Compliance: Key for demonstrating conformity with legislative requirements such as RoHS, REACH, and similar global directives limiting hazardous substance content in plastics.
• Manufacturing Quality Control: Used by polymer and plastic manufacturers to screen incoming raw materials, monitor production processes, and test finished goods for compliance with internal and external substance restrictions.
• Environmental and Consumer Safety: Applied in the analysis of electronics, toys, packaging, automotive components, and other consumer products to ensure reduced environmental impact and public health risk.
• Third-Party Verification and Certification: Laboratory and certification bodies utilize this standard to provide independent verification of material composition.
• Research and Development: Supports innovation in polymer formulation by enabling precise monitoring of additive and contaminant levels during new material development.

Related Standards

• ASTM D883: Terminology Relating to Plastics
• ASTM D3641: Practice for Injection Molding Test Specimens of Thermoplastic Materials
• ASTM D4703: Practice for Compression Molding Thermoplastic Materials into Test Specimens, Plaques, or Sheets
• ASTM D6299: Practice for Statistical Quality Assurance and Control Charting Techniques
• ASTM E29: Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• ASTM E135: Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• ASTM E177: Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• ASTM E691: Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• ASTM E1361: Guide for Correction of Interelement Effects in X-Ray Spectrometric Analysis
• ASTM F2576: Terminology Relating to Declarable Substances in Materials

Keywords: ASTM F2617, EDXRF, polymeric materials, hazardous elements analysis, lead detection in plastics, chromium, cadmium, bromine, mercury, plastics compliance testing, standard test method, RoHS, REACH, quality control, X-ray fluorescence spectrometry

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2617 − 15 (Reapproved 2023)
Standard Test Method for
Identification and Quantification of Chromium, Bromine,
Cadmium, Mercury, and Lead in Polymeric Material Using
Energy Dispersive X-ray Spectrometry
This standard is issued under the fixed designation F2617; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method describes an energy dispersive X-ray
fluorescence (EDXRF) spectrometric procedure for identifica-
2. Referenced Documents
tion and quantification of chromium, bromine, cadmium,
2.1 ASTM Standards:
mercury, and lead in polymeric materials.
D883 Terminology Relating to Plastics
1.2 This test method is not applicable to determine total
D3641 Practice for Injection Molding Test Specimens of
concentrations of polybrominated biphenyls (PBB), polybro-
Thermoplastic Molding and Extrusion Materials
minated diphenyl ethers (PBDE) or hexavalent chromium. This
D4703 Practice for Compression Molding Thermoplastic
test method cannot be used to determine the valence states of
Materials into Test Specimens, Plaques, or Sheets
atoms or ions.
D6299 Practice for Applying Statistical Quality Assurance
and Control Charting Techniques to Evaluate Analytical
1.3 This test method is applicable for a range from 20 mg/kg
Measurement System Performance
to approximately 1 wt % for chromium, bromine, cadmium,
E29 Practice for Using Significant Digits in Test Data to
mercury, and lead in polymeric materials.
Determine Conformance with Specifications
1.4 This test method is applicable for homogeneous poly-
E135 Terminology Relating to Analytical Chemistry for
meric material.
Metals, Ores, and Related Materials
1.5 The values stated in SI units are to be regarded as the
E177 Practice for Use of the Terms Precision and Bias in
standard. Values given in parentheses are for information only.
ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to
1.6 This test method is not applicable to quantitative deter-
Determine the Precision of a Test Method
minations for specimens with one or more surface coatings
E1361 Guide for Correction of Interelement Effects in
present on the analyzed surface; however, qualitative informa-
X-Ray Spectrometric Analysis
tion may be obtained. In addition, specimens less than infi-
F2576 Terminology Relating to Declarable Substances in
nitely thick for the measured X rays, must not be coated on the
Materials
reverse side or mounted on a substrate.
1.7 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions:
responsibility of the user of this standard to establish appro-
3.1.1 Definitions of terms applying to XRF, plastics and
priate safety, health, and environmental practices and deter-
declarable substances appear in Terminology E135, Terminol-
mine the applicability of regulatory limitations prior to use.
ogy D883 and Terminology F2576, respectively.
1.8 This international standard was developed in accor-
3.1.2 Compton scatter—the inelastic scattering of an X-ray
dance with internationally recognized principles on standard-
photon through its interaction with the bound electrons of an
ization established in the Decision on Principles for the
atom; this process is also referred to as incoherent scatter.
Development of International Standards, Guides and Recom-
3.1.3 Rayleigh scatter—the elastic scattering of an X-ray
photon through its interaction with the bound electrons of an
atom; this process is also referred to as coherent scatter.
This test method is under the jurisdiction of ASTM Committee F40 on
Declarable Substances in Materials and is the direct responsibility of Subcommittee
F40.01 on Test Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2023. Published November 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2008. Last previous edition approved in 2015 as F2617 – 15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F2617-15R23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2617 − 15 (2023)
3.1.3.1 Discussion—The measured count rate of Compton ascertain the conformance of the product under test to manu-
and Rayleigh scattered radiation varies depending upon speci- facturing specifications. Typical time for a measurement is 5 to
men composition and may thus be used to compensate for 10 min per specimen, depending on the specimen matrix and
matrix effects. One option is to use the measured count rate of the capabilities of the EDXRF spectrometer.
the Compton scatter in the same manner as the measured count
rate of an internal standard element. Alternatively, the mea- 6. Interferences
sured count rate of the Compton scatter or the Compton/
6.1 Spectral Interferences—Spectral interferences result
Rayleigh scatter ratio may be used indirectly for estimating the
from the behavior of the detector subsystem of the spectrom-
effective mass absorption coefficient of the specimen, which is
eter and from scattering of X rays by the specimen, by a
used to compensate for matrix effects. The concept of correc-
secondary target or by a monochromator, if the spectrometer is
tions based on the Compton scatter effect is discussed as an
so equipped. Overlaps among the X-ray lines from elements in
optional part of several calibration choices in this standard.
the specimen are caused by the limited resolution of the
3.1.4 fundamental parameters (FP) model—a model for
detection subsystem. Depending upon the resolution of the
calibration of X-ray fluorescence response, including the cor-
detector system, the peaks from Zn, Br, Hg and Pb may overlap
rection of matrix effects, based on the theory describing the
with one another. Peaks from Cd may overlap with peaks from
physical processes of the interactions of X rays with matter.
Ca, Sn, or other elements. Interactions of photons and electrons
3.1.5 homogeneous polymeric material—polymeric mate- inside the detector give rise to additional peaks in a spectrum
rial is considered homogeneous for XRF when the elemental known as escape peaks and sum peaks. Fundamental Param-
composition is independent with respect to the measured eters equations require that the measured net count rates be free
location on the specimen and among separate specimens from line overlap effects. Some empirical approaches incorpo-
prepared from the same polymeric material. rate line overlap corrections in their equations. Manufacturers’
software may provide tools to compensate for overlapped
3.1.6 infinite thickness (or critical thickness)— the thickness
peaks, escape peaks, and sum peaks in spectra. The degree of
of specimen which, if increased, yields no increase in intensity
line overlap and the best method to account or correct for it
of secondary X rays, due to absorption by the polymer matrix.
must be ascertained on an individual basis and must be
3.1.6.1 Discussion—This thickness varies with secondary
considered when calibrating the instrument.
X-ray energy, or wavelength.
6.2 Interelement Effects—Interelement effects, also called
3.2 Abbreviations:
matrix effects, exist among all elements as the result of
3.2.1 EDXRF—energy dispersive X-ray fluorescence
absorption of fluorescent X rays (secondary X rays) by atoms
3.2.2 FP—fundamental parameters
in the specimen. Absorption reduces the apparent sensitivity
3.2.3 PBB—polybrominated biphenyl
for the element. In contrast, the atom that absorbs the X rays
3.2.4 PBDE—polybrominated diphenyl ether
may in turn emit a fluorescent X ray, increasing the apparent
sensitivity for the second element. Mathematical methods may
4. Summary of Test Method
be used to compensate for matrix effects. A number of
4.1 The optimum test sample is a smooth plaque or disk
mathematical correction procedures are commonly utilized
large enough to cover the viewed area of the spectrometer.
including full FP treatments and mathematical models based on
Suitable specimens may be die-cut from extruded sheets, or
influence coefficient algorithms. The influence coefficients may
molded from resin pellets, from powders or from granules.
be calculated either from first principles or from the empirical
data, or some combination of the two approaches. See Guide
4.2 The specimen is placed in the X-ray beam, and the
E1361 for examples of these approaches. Also, consult the
appropriate region of its spectrum is measured to give the count
software manual for the spectrometer for information on the
rates or fluorescent intensities of lead, mercury, cadmium,
approaches provided with the spectrometer. Any of these that
chromium and bromine.
will achieve the necessary analytical accuracy is acceptable.
4.3 The EDXRF spectrometer is calibrated by one of several
Examples of common interelement effects are listed in Table 1.
approaches including fundamental parameters and empirical,
classical curve construction, with either empirical or theoreti-
7. Apparatus
cal influence coefficients, from measured polymer reference
materials. The calibration may be performed by the manufac- 7.1 EDXRF Spectrometer—Designed for X-ray fluorescence
analysis with energy dispersive selection of radiation. The
turer or by the user.
spectrometer is equipped with specimen holders and a speci-
4.4 Choices of appropriate characteristic X-ray lines and
men chamber. Any EDXRF spectrometer may be used if its
spectrometer test conditions may vary according to each
design incorporates the following features.
element and with factors such as detector response, concentra-
7.1.1 Source of X-ray Excitation , capable of exciting the
tion range and other elements present in the polymer matrix.
recommended lines listed in Table 2, typically an X-ray tube.
5. Significance and Use
7.1.2 X-ray Detector, with sufficient energy resolution to
5.1 This test method is intended for the determination of resolve the recommended lines listed in Table 2. An energy
chromium, bromine, cadmium, mercury, and lead, in homoge- resolution of better than 250 eV at Mn K-L (Kα) has been
2,3
neous polymeric materials. The test method may be used to found suitable.
F2617 − 15 (2023)
TABLE 1 Common Interelement Effects in Formulated Plastics mens containing the relevant elements (Cr, Br, Cd, Hg, and Pb) or
elements that have fluorescence with the same energies as the elements of
Cause Effect
interest.
Absorption by Cl in PVC Reduced sensitivity for all analytes as
compared to when they are occurring
at the same concentration level in 8. Reagents and Materials
polyolefins
8.1 Purity of Reagents —Reagent grade chemicals shall be
Polymers of similar composition but Differences in C/H among calibrants
used in all tests. Unless otherwise indicated, it is intended that
differences in the relative and samples may result in biases of a
all reagents conform to the specifications of the Committee on
concentrations of H and C few percent (relative).
Analytical Reagents of the American Chemical Society (ACS)
Unmeasured elements B, N, O, and F If concentrations differ from the
where such specifications are available. Other grades may be
present in the matrix of the polymer, calibrants, substantial concentrations
used provided it is first ascertained that the reagent is of
for example, amide, fluorinated, and of these elements may cause
sufficiently high purity to permit its use without lessening the
terephthalate compounds. significant changes in both apparent
sensitivity and background count rates.
accuracy of the determination. Reagents used include all
materials used for the preparation of reference materials and
Absorption by elements present in Reduction of apparent sensitivity for
for cleaning of specimens.
flame-retardant compounds such as most analytes
PBBs, PBDEs, and Sb O
2 3
8.2 Reagents:
Absorption by Na, P, S, Ca, Ti, Zn, Reduction of apparent sensitivity for
8.2.1 Isopropanol or ethanol.
Mo, Sn, Ba, and other elements most analytes
8.2.2 Nitric acid (HNO ).
included in a formulation as fillers or
8.2.3 Hexane.
performance additives
8.2.4 Deionized water (H O).
8.3 Gloves—Disposable cotton gloves are recommended for
TABLE 2 Recommended X-ray Lines for Individual Analytes
handling reference materials and other specimens to minimize
NOTE 1—Other choices may provide adequate performance. contamination.
Analyte Preferred Line Secondary Line
8.4 Appropriate personal protective equipment for the han-
Chromium, Cr K-L (Kα )
2,3 1,2
dling of reagents.
Bromine, Br K-L (Kα ) K-M (Kβ )
2,3 1,2 2,3 1,3
Cadmium, Cd K-L (Kα ) K-M (Kβ )
2,3 1,2 2,3 1,3 8.5 Reference Materials:
Mercury, Hg L -M (Lα )
3 4,5 1,2
8.5.1 Polymer reference materials are available from both
Lead, Pb L -M (Lβ ) L -M (Lα )
2 4 1 3 4,5 1,2
metrology institutes and commercial sources. Some are pro-
vided in disk form, and some are available as granules or
extruded pellets.
8.5.2 Reference materials may be prepared by adding
7.1.3 Signal Conditioning and Data Handling Electronics
that include the functions of X-ray counting and peak process- known amounts of pure compounds or additives (or both), to
an appropriate polymeric base material. It is recommended to
ing.
make reference materials using the same base polymer as the
7.2 The following spectrometer features and accessories are
unknown samples.
optional:
8.5.2.1 Thorough mixing of ingredients is required for
7.2.1 Beam Filters—Used to make the excitation more
optimum homogeneity. Options may include grinding, melt-
selective and reduce background count rates.
blending, repeated extrusion, and solvent dissolution.
7.2.2 Secondary Targets—Used to produce semi-
8.5.2.2 Elemental concentrations may be calculated from
monochromatic radiation enhancing sensitivity for selected
the concentrations and molecular formulae of the compounds
X-ray lines and to reduce spectral background for improved
and additives used.
detection limits. The use of monochromatic radiation also
8.5.2.3 The elemental compositions of user-prepared refer-
allows the simplification of FP calculations.
ence materials must be confirmed by one or more independent
7.2.3 Specimen Spinner—Used to reduce the effect of sur-
analytical methods.
face irregularities of the specimen.
7.2.4 Vacuum Pump—For improved sensitivity of atomic 8.6 Quality Control Samples:
8.6.1 To ensure the quality of the results, analyze quality
numbers 20 (Ca) or lower, the X-ray optical path may be
evacuated using a mechanical pump. control (QC) samples at the beginning and at the end of each
batch of specimens or after a fixed number of specimens, but at
7.2.5 Helium Flush—For improved sensitivity of atomic
numbers 20 (Ca) or lower, the X-ray optical path may be least once each day of operation. If possible, the QC sample
shall be representative of samples typically analyzed. The
flushed with helium.
material shall be homogeneous and stable under the anticipated
7.3 Drift Correction Monitor(s)—Due to instability of the
measurement system, the sensitivity and background of the
spectrometer may drift with time. Drift correction monitors
Reagent Chemicals, American Chemical Society Specifications, American
may be used to correct for this drift. The optimum drift
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
correction monitor specimens are permanent materials that are
listed by the American Chemical Society, see Annular Standards for Laboratory
stable with time and repeated exposure to X rays [Note 1].
Chemicals, BDH Ltd. Poole, Dorset, UK, and the United States Pharmacopeia and
NOTE 1—Suitable drift correction monitors may be fused bead speci- National Formulary, U.S. Pharmacopeia Convention, Inc. (USPC), Rockville, MD.
F2617 − 15 (2023)
storage conditions. An ample supply of QC sample material 10.2.2 A solution of 5 % HNO in deionized water for
shall be available for the intended period of use. removal of polar/hydrophilic contaminants (for example, salts
and most mould release agents).
9. Hazards 10.2.3 Hexane for cleaning of polyamide and polyester
specimens.
9.1 Occupational Health and Safety standards for X rays
and ionizing radiation shall be observed. It is also recom- 10.3 Care shall be taken to handle the specimen in such a
mended that proper practices be followed as presented by most way that oils and salts from the skin do not contaminate the
manufacturers’ documentation. Guidelines for safe operating portions of the specimen that will be placed in the X-ray beam
procedures are also given in current handbooks and publica- path of the spectrometer. The use of disposable cotton gloves is
tions from original equipment manufacturers. For more infor-
recommended.
mation see similar handbooks on radiation safety. NOTE 2—Refer to Appendix X1 for alternative specimen handling
techniques.
9.2 Warning—Appropriate precautions are recommended
NOTE 3—Materials with a matrix of low atomic number elements, such
when working with the elements and compounds of chromium,
as polymeric materials, exhibit relatively low X-ray absorption. This leads
to a requirement that the specimens must be thick, generally in excess of
bromine, cadmium, mercury, and lead in creating polymer
several millimeters, depending on the X-ray energies to be measured and
mixtures and fused beads.
the composition of the matrix. A minor contribution to the effect comes
from the geometry of the instrument used. A specimen thickness of 2 mm
10. Specimen Preparation
is commonly used; however, some laboratories employ lesser or greater
thickness (for example, 6 mm to more closely approach infinite thickness).
10.1 From the polymer to be tested, obtain a flat, smooth
The convenience of making discs of the same thickness for all specimens,
piece that is large enough to cover the viewed area of the
instead of infinite thickness, may be a factor for user consideration. In
spectrometer [Note 2]. Specimens shall have no obvious voids
general, more accurate and precise results may be obtained when the
reference materials and the unknowns are of infinite thickness or of the
within the measured area. It is preferable that the test specimen
same thickness.
be either of infinite thickness [Note 3] or the same thickness as
NOTE 4—Variations of 10 % relative in thickness at a level of 2 mm
the reference materials. The minimum recommended thickness
have been observed to result in count rate differences of 5 to 10 %. In
is 2 mm (0.08 in.) [Note 4].
some cases the effects on the results caused by the variations in thickness
10.1.1 Specimens taken directly from molded components
may be corrected for by the instrument manufacturer’s software or by the
calibration, or both.
of a product may be analyzed without modification provided
NOTE 5—Cleaning of reference materials may invalidate the certifica-
their geometry and surface characteristics are suitable. Exces-
tion. The user is cautioned to consult the certificate of analysis or contact
sive curvature or rough surface texture will affect the results of
the provider of the reference material for instructions.
the analysis.
10.1.2 Compression or Injection Molding —Specimens may
11. Preparation of Apparatus
be compression molded from pellets, granules or powder.
11.1 Allow the XRF instrument to stabilize for operation
General guidelines for molding may be found in Practice
according to the manufacturer’s guidelines.
D4703 for compression molding and Practice D3641 for
injection molding. Specific conditions for molding specimens
11.2 Follow the manufacturer’s recommendations [Note 6]
may be obtained from the appropriate material specification, if
and set up measurement conditions (X-ray tube excitation
one is available, material supplier’s recommendation, or past
voltage, tube current, filters, etc.) to measure the count rates of
experience. Select conditions to produce a smooth, plane
the preferred lines of chromium, bromine, cadmium, mercury,
surface without voids. Since the specimens will not be used for
and lead as suggested in Table 2.
mechanical testing, cooling and heating rates specified for
11.3 If applicable, measure the Compton scatter radiation
some materials, are not critical.
resulting from scatter of X-ray tube characteristic lines from
10.1.3 Specimens may be obtained from sheets of material
the samples [Note 7].
by cutting, punching, or die cutting. When analyzing thin films
11.4 Calculate a minimum measurement time resulting in a
and foils, it is acceptable to stack layers of films of the same
maximum counting statistical error (%CSE) of less than 5 %
composition to generate the required thickness. Care must be
for a specimen containing approximately 100 mg/kg of the
taken to ensure that the layers are in full contact across the
analyte. The required counting time may be calculated by using
viewed area in the spectrometer and that no air is trapped
Eq 1:
between layers.
10.1.4 Specimens shall not have surface coatings, nor shall
=
%CSE 5 100/ ~R·t! (1)
they be attached to a substrate, if the specimen is less than
where:
infinitely thick with respect to the X rays of the primary beam,
that is, from the X-ray source.
R = net count rate (in counts per second), and
t = counting time in seconds.
10.2 Prior to measurement, samples of polymers must be
cleaned by rinsing with appropriate solvents [Note 5]. In 11.4.1 The product of R and t equals the area under the peak
general, non-solvents for the polymer under investigation are
in EDXRF measurements. This time corresponds to a measur-
appropriate. The following cleaning agents may be used. ing time which results in collection of more than 400 counts
10.2.1 Isopropanol or ethanol for removal of non-polar (net). Overall measurement time shall not exceed 20 min per
contaminants/hydrophobic (for example, grease). specimen [Note 8].
F2617 − 15 (2023)
11.5 Ensure the software removes escape peaks and sum 12.2.3.1 As an option, the net count rates may first be
peaks from the spectrum. divided by the Compton scatter count rate for the specimen (or
the background count rate, if Compton scatter cannot be
11.6 Ensure the software subtracts the background of the
measured).
spectrum. For low atomic number materials, background
12.2.4 Include significant interelement effects (see 6.2) in
subtraction is necessary to compensate for varying matrices.
the regression model by using influence coefficients.
Measurement strategies that determine count rates using library
12.2.5 If the spectrum processing options do not include
spectra or deconvolution may include background subtraction
corrections for peak overlaps, corrections must be included in
in which case no separate background subtraction is required.
the regression model.
NOTE 6—Many spectrometers use measurement conditions configured
by the manufacturer. The user is cautioned to confirm that pre-configured
12.3 FP Calibration:
instruments conform to this standard.
12.3.1 Matrix correction procedures by FP are based on
NOTE 7—A background region from 23.5 to 23.7 keV may be used as
mathematical descriptions of the most important interactions
an alternative for the Compton scatter radiation. Depending on the anode
between X-ray photons and matter. Calibration with FP may be
material of the X-ray tube (or the secondary target), Compton scatter
radiation may be observable. For example, tube anodes consisting of Mo, done using very few standards because the only parameters to
Ag, Rh exhibit clear Compton scattered K-series radiation; while the
be determined are the slope and intercept of the calibration
Compton scatter when using tubes with anodes such as Cr or Ti is of little
...