ASTM E1724-95(2001)
(Guide)Standard Guide for Testing and Certification of Metal and Metal-Related Reference Materials (Withdrawn 2010)
Standard Guide for Testing and Certification of Metal and Metal-Related Reference Materials (Withdrawn 2010)
SIGNIFICANCE AND USE
This guide describes the suggested procedures for the preparation, testing, and certification of reference materials (RMs) to be used in the calibration, verification, and control of methods used to characterize the chemical composition of metals, ores, and related materials.
Certified reference materials are frequently rare and valuable commodities requiring investment of considerable cost and production time. They are frequently available for only a limited portion of a user’ range of interest.
When comparative analytical methods are employed, appropriate CRMs are often unavailable for calibration. In this case, the use of RMs is indicated as the alternative choice.
The use of uncertified homogeneous materials is appropriate for control chart programs where relative data consistency is being monitored. The use of CRMs for such purposes is often a misuse of valuable CRM stocks, especially when uncertified materials of suitable homogeneity are available. For information on the use and misuse of CRMs, see ISO Guide 33 and NBS Special Publication 260-100.5
Use CRMs and RMs with caution in the validation of analytical methods. The danger involves a potential for undetected systematic error, since the same methodology being validated may have been used to establish the values for the CRMs or RMs. For more information on the use of CRMs in the validation of analytical methods, see NIST Special Publication 829.6
SCOPE
1.1 This guide describes procedures to be considered for the testing and certification of metal, ore, and metal-related reference materials in the form of blocks, disks, rods, wires, chips, and powders.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This guide describes procedures to be considered for the testing and certification of metal, ore, and metal-related reference materials in the form of blocks, disks, rods, wires, chips, and powders.
Formerly under the jurisdiction of Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials, this guide was withdrawn in February 2010 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E1724 – 95 (Reapproved 2001)
Standard Guide for
Testing and Certification of Metal, Ore, and Metal-Related
Reference Materials
This standard is issued under the fixed designation E1724; 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 Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and
Wrought Iron
1.1 This guide describes procedures to be considered for the
E351 Test Methods for Chemical Analysis of Cast Iron—
testing and certification of metal, ore, and metal-related refer-
All Types
ence materials in the form of blocks, disks, rods, wires, chips,
E716 Practices for Sampling Aluminum and Aluminum
and powders.
Alloys for Spectrochemical Analysis
1.2 This standard does not purport to address all of the
E826 Practice for Testing Homogeneity of a Metal Lot or
safety concerns, if any, associated with its use. It is the
Batch in Solid Form by SparkAtomic Emission Spectrom-
responsibility of the user of this standard to establish appro-
etry
priate safety and health practices and determine the applica-
E877 Practice for Sampling and Sample Preparation of Iron
bility of regulatory limitations prior to use.
Ores and Related Materials for Determination of Chemical
2. Referenced Documents Composition
E1019 Test Methods for Determination of Carbon, Sulfur,
2.1 ASTM Standards:
Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt
E32 Practices for Sampling Ferroalloys and SteelAdditives
Alloys by Various Combustion and Fusion Techniques
for Determination of Chemical Composition
2.2 ISO Standards:
E34 Test Methods for ChemicalAnalysis ofAluminum and
ISO Guide 30 Terms and Definitions Used in Connection
Aluminum-Base Alloys
With Reference Materials
E50 Practices for Apparatus, Reagents, and Safety Consid-
ISO Guide 31 Contents of Certificates of Reference Mate-
erations for Chemical Analysis of Metals, Ores, and
rials
Related Materials
ISO Guide 33 Uses of Certified Reference Materials
E55 Practice for Sampling Wrought Nonferrous Metals and
ISO Guide 35 Certification of Reference Materials—
Alloys for Determination of Chemical Composition
General and Statistical Principles
E59 Practice for Sampling Steel and Iron for Determination
of Chemical Composition
3. Terminology
E88 Practice for Sampling Nonferrous Metals andAlloys in
3.1 Definitions—For definitions of terms used in this guide,
Cast Form for Determination of Chemical Composition
refer to Terminology E135.
E135 Terminology Relating to Analytical Chemistry for
3.2 Definitions of Terms Specific to This Standard:
Metals, Ores, and Related Materials
3.2.1 certification report—a document giving detailed in-
E178 Practice for Dealing With Outlying Observations
formation, supplementary to that contained in a certificate, on
E255 Practice for Sampling Copper and Copper Alloys for
the preparation of the material and the methods of measure-
the Determination of Chemical Composition
ment used in obtaining the certified value(s) for a given
E350 Test Methods for ChemicalAnalysis of Carbon Steel,
reference material. It includes a summary of the results
obtained (including a description of all factors affecting accu-
This guide is under the jurisdiction of ASTM Committee E01 on Analytical
racy) and a description of the way in which the results were
Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of
treated statistically.
Subcommittee E01.22 on Laboratory Quality.
3.2.2 certified reference material (CRM)—reference mate-
Current edition approved Jan. 10, 2001. Published January 2001. Originally
rial accompanied by a certificate, one or more of whose
approved in 1995. Last previous edition approved in 1995 as E1724 – 95. DOI:
10.1520/E1724-95R01.
property values are certified by a procedure which establishes
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E1724 – 95 (2001)
itstraceabilitytoanaccuraterealizationoftheunitinwhichthe yields accurate results on a CRM of similar composition which
property values are expressed; each certified value is accom- was analyzed at the same time.
panied by an uncertainty at a stated level of confidence (from
4. Significance and Use
ISO Guide 30).
3.2.3 certifying body—a technically competent body (orga- 4.1 This guide describes the suggested procedures for the
nization or firm, public or private) that issues a reference preparation, testing, and certification of reference materials
material certificate which provides the information detailed in (RMs) to be used in the calibration, verification, and control of
ISO Guide 31. methods used to characterize the chemical composition of
metals, ores, and related materials.
3.2.4 comparative analytical method—an analytical proce-
4.2 Certified reference materials are frequently rare and
dure that requires the use of CRMs, reference materials (RMs),
valuable commodities requiring investment of considerable
or, in certain instances, primary chemical standards for cali-
cost and production time. They are frequently available for
bration. Methods vary widely in the number of such CRMs
only a limited portion of a user’s range of interest.
required and the degree to which such CRMs must match
4.3 When comparative analytical methods are employed,
unknown samples.
appropriate CRMs are often unavailable for calibration. In this
3.2.5 definitive analytical method—an analytical procedure
case, the use of RMs is indicated as the alternative choice.
that does not require the use of CRMs, RMs, or primary
4.4 The use of uncertified homogeneous materials is appro-
chemical standards to achieve accurate results. Examples
priate for control chart programs where relative data consis-
include gravimetry, coulometry, specific titrimetric methods,
tency is being monitored. The use of CRMs for such purposes
and isotope dilution mass spectrometry. Each individual labo-
is often a misuse of valuable CRM stocks, especially when
ratory should validate its performance of such methods with
uncertifiedmaterialsofsuitablehomogeneityareavailable.For
CRMs, RMs, or primary chemical standards.
information on the use and misuse of CRMs, see ISO Guide 33
3.2.6 method of demonstrated accuracy—a test method for
and NBS Special Publication 260-100.
which proof of accuracy has been published, even though it
4.5 Use CRMs and RMs with caution in the validation of
may not fall within the category of a reference method.
analytical methods. The danger involves a potential for unde-
3.2.7 primary chemical standard—a pure metal or a com-
tected systematic error, since the same methodology being
pound of sufficient high purity to permit its use in the
validated may have been used to establish the values for the
calibration or validation of analytical methods.
CRMs or RMs. For more information on the use of CRMs in
3.2.8 reference material (RM)—amaterialorsubstance,one
the validation of analytical methods, see NIST Special Publi-
ormoreofwhosepropertyvaluesaresufficientlyhomogeneous
cation 829.
and well established to be used for the calibration of an
apparatus, the assessment of a measurement method, or for
5. Hazards
assigning values to materials.
5.1 The preparation of reference materials involves hazards
3.2.9 reference material certificate—adocumentstatingone
associated with the melting, annealing, casting, sampling,
or more property values and their uncertainties and confirming
forging, rolling, atomizing, pickling, shot blasting, and ma-
thatthenecessaryprocedureshavebeencarriedouttoestablish
chining of metal. Similarly, hazards are encountered in crush-
their validity and traceability.Areference material certificate is
ing, grinding, and sieving particulate and powdered materials.
an essential attribute of CRM.
5.2 For precautions related to the analysis of reference
3.2.10 reference method—a thoroughly investigated materials, see Practices E50.
method, clearly and exactly describing the necessary condi-
6. Justification of Production
tions and procedures for the measurement of one or more
property values that has been shown to have accuracy and
6.1 Reference materials are needed to calibrate, verify, and
precision commensurate with its intended use and can be used
control instrument methods when sufficient certified reference
to assess the accuracy of other methods for the same measure-
materials of the required composition or form, or both, are not
ment, particularly in permitting the characterization of an RM.
available from certifying bodies.
This includes all national or international standard methods,
6.2 Alloy types or grades not available from any certifying
which may not be classified as definitive methods because they
body are often needed to match the composition to be tested.
are calibrated against standard solutions of pure chemical
6.3 A study should be made to estimate the cost of RM
substances.
production and testing. It is important that users remain aware
3.2.11 traceability—property of a result of a measurement
that the preparation of RMs has an associated cost based on
whereby it can be related, with stated uncertainty, to stated factors such as material cost, facility usage charges, personnel
references, usually national or international standards, through labor rates, outside laboratory fees, and so forth, in which the
an unbroken chain of comparisons (ISO Guide 30).
3.2.12 uncertainty of a certified value—the range of values
within which the “true” value is asserted to lie with a stated NIST Special Publication 260-100, Handbook for SRM Users (1993 ed.).
Available from NIST, U.S. Department of Commerce, Gaithersburg, MD 20899.
confidence.
NIST Special Publication 829, Use of NIST Standard Reference Materials for
3.2.13 validation (of an analytical method)—evidence that
Decisions on Performance of Analytical Chemical Methods and Laboratories.
a method yields accurate results on a test sample because it Available from NIST.
E1724 – 95 (2001)
material cost is, in general, the lowest. For complex composi- 8.4 Metallurgical condition is an important consideration.
tions, the cost of preparing RMs to match the composition of Most instrumental techniques such as X-ray fluorescence,
testsamplescanexceedthatofavailableCRMs.Inthesecases, spark optical emission, and glow-discharge optical emission
the use of CRMs is recommended. use RMs in their solid metallic form. One or more of these
6.4 Astudy of the costs associated with the RM production methods may be subject to analytical bias due to the sample’s
should take into account the amount of usable material metallurgical history. In order to minimize the influence of
compared to the total amount produced. It may be necessary to metallurgical effects, the unknown sample being analyzed
produce twice as much raw material in order to obtain the should have the same metallurgical structure as the RM being
target amount of usable RM. used to calibrate the instrument response. Some instruments
may require separate calibrations for cast, chill cast, and
wrought materials. For example, in the analysis of iron base
7. Types of Reference Materials and Reference Material
Forms Covered in This Guide metals, X-ray fluorescence is subject to thermal history effects
if the heat treatment causes the precipitation of a second phase
7.1 Reference Materials:
and affects the homogeneity of the material.
7.1.1 Multielement Reference Material— Certified for a
complete composition (may or may not include trace element
9. Production to Final Form
composition).
9.1 This guide will not specify the procedures used for
7.1.1.1 Grade-Specific Reference Material— Meets or is
melting or production of the RM into the final form. Methods
close to the compositional specification for all elements of a
will vary in accordance with composition requirements.
particular grade of material.
9.2 Some portions of the candidate material may need to be
7.1.1.2 Drift-Correction Reference Material—A cast or
discarded if homogeneity testing indicates the material is not
wrought material evaluated for an array of elements, useful for
uniform.
drift correction of instrumental methods.Adrift-correction RM
may conform to a compositional specification.
10. Sample Identification and Recordkeeping
7.1.2 Element-Specific Reference Material—Certified for a
small number of elements.Acommon type of element-specific
10.1 Material identification is required at all times during
RM consists of chips or pins certified for carbon, sulfur,
RM production, especially during random sampling for the
nitrogen, oxygen, or hydrogen, or a combination thereof.
homogeneity testing. Proper sample identification will ensure
7.2 Reference Material Forms:
that unacceptable portions of a candidate material may be
7.2.1 Monolithic Solids:
isolated from the usable portion.
7.2.1.1 Castings,
10.2 Proper recordkeeping is vital during the entire process
7.2.1.2 Wrought material finished to bar form, and
of the RM production, from the initial determination of the
7.2.1.3 Rod and wire material. need to produce an RM, to the preparation of the analysis
7.2.2 Particulates: report.
7.2.2.1 Chips, and
11. Homogeneity Check
7.2.2.2 Powders.
11.1 Estimatetheamountofacceptableinhomogeneityprior
NOTE 1—Inmanycases,fullcompositiondata,althoughnotnecessarily
to the production of the material. The homogeneity testing
certified, will be needed to permit corrections for interferences in various
instrumental methods, especially for critical elements at low concentra-
procedure shall be designed to test at least the minimum
tions.
sample size or test area required for its intended use.
11.2 Homogeneity testing is a crucial part of RM evalua-
8. Specifications for the Finished Reference Material
tion. Costs can be held to a minimum if a preliminary
8.1 If a composition is to be made by a melting process, a
homogeneity test, as described in Practice E826, is performed
realistic approach should be taken when determining the
before expensive fabrication and extensive testing is under-
number of elements and their concentrations in each RM. If a taken. It may be necessary to design special test m
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