ASTM D6568-00(2018)

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: D6568 − 00 (Reapproved 2018)
Standard Guide for
Planning, Carrying Out, and Reporting Traceable Chemical
Analyses of Water Samples
This standard is issued under the fixed designation D6568; 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 3. Terminology
1.1 This guide sets a protocol for generating and reporting
3.1 Definitions:
chemical analyses that are traceable to SI units or to certified
3.1.1 For definitions of terms used in this standard, refer to
reference materials in laboratories that serve the water and
Terminology D1129.
environmental industry.
3.2 Definitions of Terms Specific to This Standard:
1.2 This standard does not purport to address all of the
3.2.1 certified reference material, n—reference material,
safety concerns, if any, associated with its use. It is the
accompanied by a certificate, one or more of whose property
responsibility of the user of this standard to establish appro-
values are certified by a procedure which established its
priate safety, health, and environmental practices and deter-
traceability to an accurate realization of the unit in which the
mine the applicability of regulatory limitations prior to use.
property values are expressed, and for which each certified
1.3 This international standard was developed in accor-
value is accompanied by an uncertainty at a stated level of
dance with internationally recognized principles on standard-
confidence. ISO Guide 30
ization established in the Decision on Principles for the
3.2.1.1 Discussion—There is significant variation in the
Development of International Standards, Guides and Recom-
overall quality of commercially available certified reference
mendations issued by the World Trade Organization Technical
materials and caution should be used when choosing certified
Barriers to Trade (TBT) Committee.
referencematerials.UsePracticeD6362toprovideguidanceas
to what information needs to be included on Certificate of a
2. Referenced Documents
certified reference material.
2.1 ASTM Standards:
3.2.2 SI units, n—this is the International System of Units
D1129 Terminology Relating to Water
(SI) which is the modernized metric system as described in
D6362 Practice for Certificates of Reference Materials for
IEEE/ASTM SI 10–1997. A SI Quick Reference Guide is
Water Analysis
included in ASTM BOS Volumes 11.01 and 11.02.
IEEE/ASTM SI 10–1997 Standard for Use of the Interna-
tional System of Units (SI): The Modern Metric System
3.2.3 traceability, n—property of the result of a measure-
2.2 Other Documents:
ment or the value of a standard whereby it can be related, with
ISOGuide17025 GeneralRequirementsfortheCompetence
a stated uncertainty, to stated references, usually national or
of Calibration and Testing Laboratories
international standards, through an unbroken chain of
ISO Guide 30 Terms and Definitions Used in Connection
comparisons. ISO Guide 30
with Reference Materials
3.2.4 uncertainty (of measurement), n—parameter, associ-
VIM International Vocabulary of Basic and General Terms
ated with the result of a measurement that characterizes the
in Metrology, ISO: 2nd ed., 1993
dispersion of values that could reasonably be attributed to the
measured. VIM
3.2.5 work plan, n—a documented procedure intended for
use by a laboratory to meet the measurement traceability
requirements of a defined need.
This guide is under the jurisdiction of ASTM Committee D19 on Water and is
thedirectresponsibilityofSubcommitteeD19.02onQualitySystems,Specification,
4. Significance and Use
and Statistics.
Current edition approved Aug. 1, 2018. Published September 2018. Originally
4.1 This guide establishes basic requirements which should
approved in 2000. Last previous edition approved in 2011 as D6568 – 00 (2011).
be met by water and environmental laboratories that generate
DOI: 10.1520/D6568-00R18.
and report test chemical analyses which the laboratory client
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. desirestobetraceabletoSIunits(Note1)orcertifiedreference
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6568 − 00 (2018)
materials traceable to SI units. Traceability of chemical analy- 5.2 The laboratory shall prepare a work plan to meet the
ses is important because it provides a uniform basis for the requirements and obtain concurrence with the client.
comparison of results from different measurement systems and
5.3 The laboratory shall make the chemical analyses and
because it relates those results to our current knowledge of
issue a report.
physical laws (Note 2).
6. Procedure
NOTE1—AcertifiedreferencematerialtraceabletoSIunitsisacertified
reference material whose value can be related with a stated uncertainty 6.1 The client shall prepare a request for traceable measure-
through an unbroken change of comparisons to stated references (usually
ments and submit it to an ISO Guide 17025 compliant
national or international standards) in SI units, such as a primary
laboratory for review and acceptance, as follows.
measurement made in SI units or a national standard certified in SI units.
6.1.1 The request shall identify the source (that is, the
NOTE 2—Not all chemical analysis results can be traceable to SI units
specific sampling site, the process generating the sample, etc.),
or to certified reference material’s traceable to SI units, such as turbidity
and or total suspended solids. sampling history, configuration, and approximate composition
of the test materials, the traceable measurements to be made
4.2 Many waters-related laboratories comply with ISO
with their required maximum uncertainties. It shall also iden-
Guide 17025 and participate in Proficiency Testing Programs.
tify special requirements, such as, the need to certify that the
Laboratories that are connected to the same accreditation
materialtestedcomplieswithaspecificproductspecificationor
bodies and ProficiencyTest providers can be expected to report
that traceability must be made to a specific standard or certified
statistically similar results on the same sample. However, some
reference material. The request shall also specify if any
test methods and some certified reference materials are not
nontraceablechemicalanalysesaretobeincludedaspartofthe
supported with data traceable to SI units. Therefore, fully
project.
compliant laboratories that are not connected to the same
6.1.2 The client shall select an ISO Guide 17025 compliant
providers may report statistically different chemical analysis
laboratoryandsubmittheirrequesttothelaboratoryforreview.
results if they used the same nontraceable test method on the
6.1.3 The laboratory shall review the request, work with the
same sample. This problem could be minimized if they used
client to clarify their understanding of the need, and inform the
test methods, measurement devices, and certified reference
client of its willingness and capability to proceed.
materials that are traceable to SI units, where available.
6.2 The laboratory shall prepare a work plan (Note 4)to
4.3 Although some standard test methods and certified
meet the requirements and obtain
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