SIST-TS ISO/TS 21231:2019

TECHNICAL ISO/TS
SPECIFICATION 21231
First edition
2019-02
Water quality — Characterization of
analytical methods — Guidelines for
the selection of a representative matrix
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 4
5 Influence parameters . 5
5.1 Common parameters for all matrices . 5
5.2 Water intended for consumption . 6
5.3 Natural waters . 6
5.4 Waste waters . 6
5.5 Marine waters . 6
5.6 Recreational waters . 7
6 Selection of characteristic parameters of a matrix . 7
6.1 General . 7
6.2 All waters . 7
6.3 Waters intended for consumption . 7
6.4 Natural waters . 7
6.5 Waste waters . 7
6.6 Marine waters . 8
6.7 Recreational waters . 8
7 Available materials . 8
7.1 General . 8
7.2 Material obtained by reasonable dilution of a real matrix . 8
7.3 Artificial material . 9
7.4 Analyte-specific blank values in matrices. 9
8 Report . 9
Annex A (informative) Characterization of waters intended for human consumption and
mineral waters .10
Annex B (informative) Examples of preparation of artificial matrices and representative
characteristics .11
Annex C (informative) Occurrence of chemical substances in waste water, by industrial
activity sector .23
Annex D (informative) Leachate .32
Bibliography .33
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2,
Physical, chemical and biochemical methods.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved

Introduction
This document has been prepared for the validation of analytical methods applied to the water quality
field. It enables a laboratory to determine the characteristics of a material suitable for determination of
the performances of an analytical method itself.
It is not intended to provide an exhaustive inventory of all published recipes, but to propose a selection
of recipes supporting the characterization of the performances of analytical methods used by a
laboratory. For this reason, a restricted number of recipes are proposed. References giving access to
other recipes are available in the Bibliography.
This document includes four recipes for preparing marine waters and five recipes for waste waters
with controlled characteristics.
TECHNICAL SPECIFICATION ISO/TS 21231:2019(E)
Water quality — Characterization of analytical methods —
Guidelines for the selection of a representative matrix
1 Scope
This document specifies representative materials suitable for the determination of the performance
characteristics, including uncertainty, during the initial assessment of a quantitative method, used in a
laboratory, for physico-chemical water analysis.
This document focuses on five main types of water:
— waters intended for consumption (5.2);
— natural waters (5.3);
— waste waters (5.4);
— marine waters (5.5);
— recreational waters (5.6).
NOTE Other more specific or less common types of water can be incorporated in any of the above types
provided appropriate justifications. The characteristics of the standard matrix are compatible with the
characteristics of the samples handled.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 6107 (all parts), Water quality — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6107 (all parts) and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1 General vocabulary
3.1.1
matrix
set of constituents of the test sample, except the analyte (3.2.1)
Note 1 to entry: By extension, a matrix defines a group of waters characterized by similar analytical behaviour in
relation to the analytical method used.
3.1.2
accepted reference value
value that serves as an agreed-upon reference for comparison, and which is derived as:
a) a theoretical or established value, based on scientific principles;
b) an assigned or certified value, based on experimental work of some national or international
organization;
c) a consensus or certified value, based on collaborative experimental work under the auspices of a
scientific or engineering group;
d) when a), b) and c) are not available, the expectation of the (measurable) quantity, i.e. the mean of a
specified population of measurements
Note 1 to entry: In the specific context of this document, the accepted reference value (or conventionally true
value) of the sample is provided according to possibilities by:
— the value from a certified reference material certificate,
— the consensus value obtained from an inter-laboratory comparison,
— the arithmetic mean of the repeated measurement values according to the reference method,
— the target value by adding analyte to a representative matrix of the scope in question.
[SOURCE: ISO 5725-1:1994, 3.5]
3.1.3
reference material
material, sufficiently homogeneous and stable with respect to one or more specified properties, which
has been established to be fit for its intended use in a measurement process
[SOURCE: ISO Guide 35:2017, 3.1]
3.1.4
certified reference material
reference material (3.1.3), accompanied by a certificate, one or more of whose property values are
certified by a procedure which establishes traceability to an accurate realization of the unit in which
the property values are expressed, and for which each certif
...

TECHNICAL ISO/TS
SPECIFICATION 21231
First edition
2019-02
Water quality — Characterization of
analytical methods — Guidelines for
the selection of a representative matrix
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 4
5 Influence parameters . 5
5.1 Common parameters for all matrices . 5
5.2 Water intended for consumption . 6
5.3 Natural waters . 6
5.4 Waste waters . 6
5.5 Marine waters . 6
5.6 Recreational waters . 7
6 Selection of characteristic parameters of a matrix . 7
6.1 General . 7
6.2 All waters . 7
6.3 Waters intended for consumption . 7
6.4 Natural waters . 7
6.5 Waste waters . 7
6.6 Marine waters . 8
6.7 Recreational waters . 8
7 Available materials . 8
7.1 General . 8
7.2 Material obtained by reasonable dilution of a real matrix . 8
7.3 Artificial material . 9
7.4 Analyte-specific blank values in matrices. 9
8 Report . 9
Annex A (informative) Characterization of waters intended for human consumption and
mineral waters .10
Annex B (informative) Examples of preparation of artificial matrices and representative
characteristics .11
Annex C (informative) Occurrence of chemical substances in waste water, by industrial
activity sector .23
Annex D (informative) Leachate .32
Bibliography .33
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2,
Physical, chemical and biochemical methods.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved

Introduction
This document has been prepared for the validation of analytical methods applied to the water quality
field. It enables a laboratory to determine the characteristics of a material suitable for determination of
the performances of an analytical method itself.
It is not intended to provide an exhaustive inventory of all published recipes, but to propose a selection
of recipes supporting the characterization of the performances of analytical methods used by a
laboratory. For this reason, a restricted number of recipes are proposed. References giving access to
other recipes are available in the Bibliography.
This document includes four recipes for preparing marine waters and five recipes for waste waters
with controlled characteristics.
TECHNICAL SPECIFICATION ISO/TS 21231:2019(E)
Water quality — Characterization of analytical methods —
Guidelines for the selection of a representative matrix
1 Scope
This document specifies representative materials suitable for the determination of the performance
characteristics, including uncertainty, during the initial assessment of a quantitative method, used in a
laboratory, for physico-chemical water analysis.
This document focuses on five main types of water:
— waters intended for consumption (5.2);
— natural waters (5.3);
— waste waters (5.4);
— marine waters (5.5);
— recreational waters (5.6).
NOTE Other more specific or less common types of water can be incorporated in any of the above types
provided appropriate justifications. The characteristics of the standard matrix are compatible with the
characteristics of the samples handled.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 6107 (all parts), Water quality — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6107 (all parts) and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1 General vocabulary
3.1.1
matrix
set of constituents of the test sample, except the analyte (3.2.1)
Note 1 to entry: By extension, a matrix defines a group of waters characterized by similar analytical behaviour in
relation to the analytical method used.
3.1.2
accepted reference value
value that serves as an agreed-upon reference for comparison, and which is derived as:
a) a theoretical or established value, based on scientific principles;
b) an assigned or certified value, based on experimental work of some national or international
organization;
c) a consensus or certified value, based on collaborative experimental work under the auspices of a
scientific or engineering group;
d) when a), b) and c) are not available, the expectation of the (measurable) quantity, i.e. the mean of a
specified population of measurements
Note 1 to entry: In the specific context of this document, the accepted reference value (or conventionally true
value) of the sample is provided according to possibilities by:
— the value from a certified reference material certificate,
— the consensus value obtained from an inter-laboratory comparison,
— the arithmetic mean of the repeated measurement values according to the reference method,
— the target value by adding analyte to a representative matrix of the scope in question.
[SOURCE: ISO 5725-1:1994, 3.5]
3.1.3
reference material
material, sufficiently homogeneous and stable with respect to one or more specified properties, which
has been established to be fit for its intended use in a measurement process
[SOURCE: ISO Guide 35:2017, 3.1]
3.1.4
certified reference material
reference material (3.1.3), accompanied by a certificate, one or more of whose property values are
certified by a procedure which establishes traceability to an accurate realization of the unit in which
the property values are expressed, and for which each certif
...