ISO/TS 7013:2023

Water quality — Guidance and requirements for designing an interlaboratory trial for validation of analytical methods

This document specifies requirements and recommendations for the design and execution of an interlaboratory comparison for validation of new standardized analytical methods in the field of water analysis, e.g. the number of participating laboratories and time schedules. This document is based on ISO 5725-1 and ISO 5725-2. NOTE The scope of other standards in the field of interlaboratory comparison, such as ISO/IEC 17043[3] and ISO 13528[1], is proficiency testing of analytical laboratories and not interlaboratory comparison for the validation of analytical methods.

Titre manque

General Information

• Status: Published
• Publication Date: 06-Jul-2023
• ICS: 13.060.45 - Examination of water in general
• Technical Committee: ISO/TC 147/SC 2 - Physical, chemical and biochemical methods
• Drafting Committee: ISO/TC 147/SC 2 - Physical, chemical and biochemical methods
• Current Stage: 6060 - International Standard published
• Start Date: 07-Jul-2023
• Due Date: 16-Feb-2023
• Completion Date: 07-Jul-2023

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 7013
First edition
2023-07
Water quality — Guidance and
requirements for designing an
interlaboratory trial for validation of
analytical methods
Reference number
ISO/TS 7013:2023(E)
© ISO 2023

---------------------- Page: 1 ----------------------
ISO/TS 7013:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2023 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/TS 7013:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Preconditions . 1
5.1 General . 1
5.2 Special preconditions for validation of non-crucial method options in analytical
methods for organic analytes. 2
6 Design and organization . 2
6.1 Requirements for participation and call for participants. 2
6.2 Samples . 3
6.3 Information to be distributed with the samples . 4
6.4 Statistical evaluation . 4
7 Assessment . .5
8 Documentation and reporting . 5
Annex A (informative) Checklist, timetable and reporting the performance data .6
Bibliography . 8
iii
© ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/TS 7013:2023(E)
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
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 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/TS 7013:2023(E)
Introduction
The final validation step during standardization of an analytical method is the evaluation of
performance through an interlaboratory trial to demonstrate that a new method is fit for purpose.
This document is intended to assist persons organizing interlaboratory trials to design and organize
international interlaboratory comparisons for the validation of new standardized physical, chemical
and biochemical methods for water analysis.
v
© ISO 2023 – All rights reserved

---------------------- Page: 5 ----------------------
TECHNICAL SPECIFICATION ISO/TS 7013:2023(E)
Water quality — Guidance and requirements for designing
an interlaboratory trial for validation of analytical
methods
1 Scope
This document specifies requirements and recommendations for the design and execution of an
interlaboratory comparison for validation of new standardized analytical methods in the field of water
analysis, e.g. the number of participating laboratories and time schedules. This document is based on
ISO 5725-1 and ISO 5725-2.
[3]
NOTE The scope of other standards in the field of interlaboratory comparison, such as ISO/IEC 17043
[1]
and ISO 13528 , is proficiency testing of analytical laboratories and not interlaboratory comparison for the
validation of analytical methods.
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 5725-1, Accuracy (trueness and precision) of measurement methods and results — Part 1: General
principles and definitions
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5725-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
A representative number of laboratories analyse within the sample stability period the same sample
material prepared and distributed by the organizer of the interlaboratory trial. The results are used to
calculate the performance data of the standardized method (see Clause A.3).
5 Preconditions
5.1 General
The prerequisite for the performance of the interlaboratory trial is that the method development and
[2]
the validation of the individual steps of the whole measurement process according to ISO/TS 13530
have been completed.
NOTE 1 Validation of analytical methods is also described in References [4] and [5].
1
© ISO 2023 – All rights reserved

---------------------- Page: 6 ----------------------
ISO/TS 7013:2023(E)
As the aim of this kind of interlaboratory comparison is the evaluation of the performance data of an
analytical method, no technical alterations of the given protocol of the standardized analytical method
are allowed to the participants of the interlaboratory trial.
NOTE 2 This is in contrast to proficiency testing interlaboratory comparisons, where the participating
laboratories use different analytical methods for the determination of the same parameter.
All registered participants of an interlaboratory trial should get all samples. Only in exceptional cases
they could be entitled to select samples in advance, because it is important to receive as many test
results as possible. It is highly recommended that all samples are tested by the participants and results
of all parameters be submitted to the organizer of the interlaboratory trial to ensure a maximum
number of individual test results after outlier rejection within the evaluation.
If there are several options within the standardized analytical method, for example, for extraction or
detection, separate performance data are evaluated for each option and for the undifferentiated data
set. The decision to merge data sets is taken by experts of the interlaboratory trial after examination of
the influence of the chosen option on the final measurement result. It is the result of the evaluation of
the fitness for purpose of the tested standard.
5.2 Special preconditions for validation of non-crucial method options in analytical
methods for organic analytes
This subclause is not applicable to operationally defined analytical methods.
Non-crucial method options mean, only alternatives or variants of single analytical steps, as extraction
options or the change to direct injection using a highly developed apparatus instead of a specified
enrichment technique are considered non-crucial. But, changing the analytical principle like switching
from GC-MS to LC-MS is considered crucial and not the scope of this subclause. The alternatives or
options in this sense are not independent methods.
The experts in charge of the development of the standardized analytical method define whether an
option is crucial or non-crucial, based on experiments and/or experience.
In general, a method option has to be as well described as a normative method. All necessary references
to the method in the main part of the standard and vice versa shall be given. Pre-normative validation
work has to be performed as well as for the main method. Results according to the alternatives or
options shall be equivalent.
All authorized options of one single analytical step shall be mentioned in the main document. If required,
they can be described in detail in an annex. It has to be clear that all the options are equivalent and can
be used.
A documented evaluation of any alternative step of a method is needed. This has to be provided by the
experts of the responsible working group before carrying out the interlaboratory trial.
The results of the method options/alternatives of the interlaboratory trial are pooled. No separate
evaluation of the results of the different options will be performed. The question, which of the options
was applied by a laboratory, is merely additional information for documentation of the interlaboratory
trial. The experts responsible for the interlaboratory trial have to evaluate the results and document
their decision.
6 Design and organization
6.1 Requirements for participation and call for participants
The number of participants has an influence on the reliability of the statistically calculated performance
data. A minimum of 24 outlier-free data obtained from a minimum of eight lab
...

© ISO 2022 – All rights reserved
ISO/TC 147/SC 2
Date:  ISO/TS 7013:2023-02-16
ISO/TS 7013:2022(E)
ISO/TC 147/SC 2/WG 48
Secretariat: DIN
Water quality — GuidanceRequirements and requirements
fordesigningrecommendations for designing an interlaboratory trial for validation
of analytical methods
Élément introductif — Élément central — Élément complémentaire
Document type:  Technical Specification
Document subtype:
Document stage:  (60) Publication
Document language:  E

STD Version 2.9p

---------------------- Page: 1 ----------------------
© ISO 2022 – All rights reserved
COPYRIGHT PROTECTED DOCUMENT
First edition
Date: 2023-05-15
Document type:  Technical Specification
Document subtype:
Document stage:  (60) Publication
Document language:  E

STD Version 2.9p

---------------------- Page: 2 ----------------------
ISO/TS 7013:2023(E)
© ISO 2023
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’sISO's member body
in the country of the requester.
ISO Copyright Office
Ch. de Blandonnet 8 • CP 401 • CH-1214 Vernier, Geneva , Switzerland
Tel. Phone: + 41 22 749 01 11
Email: [e-mail]
Website: www.iso.orgFax + 41 22 749 09 47
[e-mail]
www.iso.org

Published in Switzerland.
ii © ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/TS 7013:2023(E)
Contents Page
Foreword . iv
1 Scope . 2
2 Normative references . 2
3 Terms and definitions . 2
4 Principle . 2
5 Preconditions . 2
6 Design and organization . 3
7 Assessment. 6
8 Documentation and reporting . 6
Anhang A (informative) Checklist, timetable and reporting the performance data . 7
Bibliography . 10
© ISO 2023 – All rights reserved iii

---------------------- Page: 4 ----------------------
ISO/TS 7013:2023(E)
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 documentsdocument 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 drawnISO draws attention to the possibility that some of the elementsimplementation of
this document may beinvolve the subjectuse of (a) patent(s). ISO takes no position concerning the
evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of
publication of this document, ISO had not received notice of (a) patent(s) which may be required to
implement this document. However, implementers are cautioned that this may not represent the latest
information, which may be obtained from the patent database available at www.iso.org/patents. 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 ).
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 2023 – All rights reserved

---------------------- Page: 5 ----------------------
ISO/TS 7013:2023(E)
Introduction
The final validation step during standardization of an analytical method is the evaluation of
performance through an interlaboratory trial to demonstrate that a new method is fit for purpose.
This document is intended to assist project leaders or organizers of persons organizing interlaboratory
trials within ISO/TC 147/SC 2 in designingto design and organizingorganize international
interlaboratory comparisons for the validation of standard analyticalnew standardized physical,
chemical and biochemical methods for water analysis.
© ISO 2023 – All rights reserved v

---------------------- Page: 6 ----------------------
TECHNICAL SPECIFICATION ISO/TS 7013:2023(E)

Water quality — Guidance document on — Requirements and
recommendations for designing an interlaboratory trial for
validation of analytical methods
1 Scope
This document specifies some detailsrequirements and recommendations for the special casedesign
and execution of designing and performing an interlaboratory comparison for validation of new
standardized analytical methods in the field of water analysis, e.g. the number of participating
laboratories, and time schedules. ItThis document is based on ISO 5725-1 and ISO 5725-2.
[ 3]
2
NOTE The scope of other standards in the field of interlaboratory comparison, such as ISO/IEC 17043 and
[1]
ISO 13528 , is proficiency testing of analytical laboratories and not interlaboratory comparison for the validation
of analytical methods.
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 5725-1, Accuracy (trueness and precision) of measurement methods and results — Part 1: General
principles and definitions
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic
method for the determination of repeatability and reproducibility of a standard measurement method
ISO/TS 13530:2009, Water quality — Guidance on analytical quality control for chemical and
physicochemical water analysis
43 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5725-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
54 Principle
A representative number of laboratories analyse within the sample stability period the same sample
material prepared and distributed by the organizer of the interlaboratory trial. The results are used to
calculate the performance data of the standardized method (see Annex Clause A.3).
© ISO 2023 – All rights reserved 1

---------------------- Page: 7 ----------------------
ISO/TS 7013:2023(E)
65 Preconditions
6.15.1 General
The prerequisite for the performance of the interlaboratory trial is that the method development and
the validation of the individual steps of the whole measurement process according to ISO/TS 13530
have been completed. Generally, this is the case when a DIS proposal has been developed based on an
approved CD.
NOTE 1: Validation of analytical methods is also described in References [3 [4] and [45].
As the aim of this kind of interlaboratory comparison is the evaluation of the performance data of an
analytical method, no technical alterations of the given protocol of the draft standardstandardized
analytical method are allowed to the participants of the interlaboratory trial.
NOTE 2 This is in contrast to proficiency testing interlaboratory comparisons, where the participating
laboratories use different analytical methods for the determination of the same parameter.
All registered participants of an interlaboratory trial should get all samples. Only in exceptional cases
they could be entitled to select samples in advance, because it is important to receive as many test
results as possible. It is highly recommended that all samples are tested by the participants and results
of all parameters be submitted to the organizer of the interlaboratory trial to ensure a maximum
number of individual test results after outlier rejection within the evaluation.
If there are several options within the draft standard, e.g.standardized analytical method, for example,
for extraction or detection, separate performance data are evaluated for each option and for the
undifferentiated data set. The decision to merge data sets is taken by experts of the working group in
charge of the development of the standardinterlaboratory trial after examination of the influence of the
chosen option on the final measurement result. It is the result of the evaluation of the fitness for
purpose of the tested standard.
6.25.2 Special preconditions for validation of non-crucial method modificationsoptions
in analytical methods for organic analytes
This subclause is not applicable to operationally defined analytical methods.
Non-crucial method modificationsoptions mean, only modificationsalternatives or variants of single
analytical steps, as extraction options or the change to direct injection using a highly developed
apparatus instead of a specified enrichment technique are considered non-crucial. But, changing the
analytical principle like switching from GC-MS to LC-MS is considered crucial and not the scope of this
subclause. The alternatives or modificationsoptions in this sense are not independent methods.
The working groupexperts in charge of the standard of the development of the standardized analytical
method defines whether a modificationan option is crucial or non-crucial, based on experiments and/or
experience.
In general, a method modificationoption has to be as well described as a normative method. All
necessary references to the method in the main part of the standard and vice versa shall be given. Pre-
normative validation work has to be performed as well as for the main method. Results according to the
alternativealternatives or modificationoptions shall be equivalent.
All authorized modificationsoptions of one single analytical step have toshall be mentioned in the main
document. If so, itrequired, they can be described in detail in an informative or normative annex. It has
to be clear that all the modificationsoptions are equivalent and maycan be used.
A documented evaluation of any non-crucial modifiedalternative step of a method is needed. This has to
be provided by the experts of the responsible working group before carrying out the interlaboratory
trial.
2 © ISO 2023 – All rights reserved

---------------------- Page: 8 ----------------------
ISO/TS 7013:2023(E)
The results of the method modificationsoptions/alternatives of the interlaboratory trial are pooled. No
separate evaluation of the results of the different modificationsoptions will be performed. The question,
which of the modificationsoptions was applied by a laboratory, is merely additional information for
documentation of the interlaboratory trial. The experts of the responsible working groupsfor the
interlaboratory trial have to evaluate the results and document their decision.
76 Design and organization
7.16.1 Requirements for participation and call for participants
The number of participants has an influence on the reliability of the statistically calculated performance
data. A minimum of 24 outlier-free data obtained from a minimum of 8eight laboratories are
mandatory. In this, it is therefore desirable to ensure that the number of laboratories registered for
participation in the interlaboratory trial is not less than 12.
Participation in this kind of interlaboratory trials is voluntary. To achieve reliable performance data,
only experienced laboratories which are able to analyse all provided test samples applying the
analytical procedures described in the corresponding draft standard shouldstandardized analytical
methodshou
...

TECHNICAL ISO/TS
SPECIFICATION 7013
First edition
Water quality — Guidance and
requirements for designing an
interlaboratory trial for validation of
analytical methods
PROOF/ÉPREUVE
Reference number
ISO/TS 7013:2023(E)
© ISO 2023

---------------------- Page: 1 ----------------------
ISO/TS 7013:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
PROOF/ÉPREUVE © ISO 2023 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/TS 7013:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Preconditions . 1
5.1 General . 1
5.2 Special preconditions for validation of non-crucial method options in analytical
methods for organic analytes. 2
6 Design and organization . 2
6.1 Requirements for participation and call for participants. 2
6.2 Samples . 3
6.3 Information to be distributed with the samples . 4
6.4 Statistical evaluation . 4
7 Assessment . .4
8 Documentation and reporting . 5
Annex A (informative) Checklist, timetable and reporting the performance data .6
Annex X (informative) Performance data . 8
Bibliography . 9
iii
© ISO 2023 – All rights reserved PROOF/ÉPREUVE

---------------------- Page: 3 ----------------------
ISO/TS 7013:2023(E)
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
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
PROOF/ÉPREUVE © ISO 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/TS 7013:2023(E)
Introduction
The final validation step during standardization of an analytical method is the evaluation of
performance through an interlaboratory trial to demonstrate that a new method is fit for purpose.
This document is intended to assist persons organizing interlaboratory trials to design and organize
international interlaboratory comparisons for the validation of new standardized physical, chemical
and biochemical methods for water analysis.
v
© ISO 2023 – All rights reserved PROOF/ÉPREUVE

---------------------- Page: 5 ----------------------
TECHNICAL SPECIFICATION ISO/TS 7013:2023(E)
Water quality — Guidance and requirements for designing
an interlaboratory trial for validation of analytical
methods
1 Scope
This document specifies requirements and recommendations for the design and execution of an
interlaboratory comparison for validation of new standardized analytical methods in the field of water
analysis, e.g. the number of participating laboratories and time schedules. This document is based on
ISO 5725-1 and ISO 5725-2.
[3]
NOTE The scope of other standards in the field of interlaboratory comparison, such as ISO/IEC 17043
[1]
and ISO 13528 , is proficiency testing of analytical laboratories and not interlaboratory comparison for the
validation of analytical methods.
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 5725-1, Accuracy (trueness and precision) of measurement methods and results — Part 1: General
principles and definitions
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5725-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
A representative number of laboratories analyse within the sample stability period the same sample
material prepared and distributed by the organizer of the interlaboratory trial. The results are used to
calculate the performance data of the standardized method (see Clause A.3).
5 Preconditions
5.1 General
The prerequisite for the performance of the interlaboratory trial is that the method development and
the validation of the individual steps of the whole measurement process according to ISO/TS 13530
have been completed.
NOTE 1 Validation of analytical methods is also described in References [4] and [5].
1
© ISO 2023 – All rights reserved PROOF/ÉPREUVE

---------------------- Page: 6 ----------------------
ISO/TS 7013:2023(E)
As the aim of this kind of interlaboratory comparison is the evaluation of the performance data of an
analytical method, no technical alterations of the given protocol of the standardized analytical method
are allowed to the participants of the interlaboratory trial.
NOTE 2 This is in contrast to proficiency testing interlaboratory comparisons, where the participating
laboratories use different analytical methods for the determination of the same parameter.
All registered participants of an interlaboratory trial should get all samples. Only in exceptional cases
they could be entitled to select samples in advance, because it is important to receive as many test
results as possible. It is highly recommended that all samples are tested by the participants and results
of all parameters be submitted to the organizer of the interlaboratory trial to ensure a maximum
number of individual test results after outlier rejection within the evaluation.
If there are several options within the standardized analytical method, for example, for extraction or
detection, separate performance data are evaluated for each option and for the undifferentiated data
set. The decision to merge data sets is taken by experts of the interlaboratory trial after examination of
the influence of the chosen option on the final measurement result. It is the result of the evaluation of
the fitness for purpose of the tested standard.
5.2 Special preconditions for validation of non-crucial method options in analytical
methods for organic analytes
This subclause is not applicable to operationally defined analytical methods.
Non-crucial method options mean, only alternatives or variants of single analytical steps, as extraction
options or the change to direct injection using a highly developed apparatus instead of a specified
enrichment technique are considered non-crucial. But, changing the analytical principle like switching
from GC-MS to LC-MS is considered crucial and not the scope of this subclause. The alternatives or
options in this sense are not independent methods.
The experts in charge of the of the development of the standardized analytical method defines whether
an option is crucial or non-crucial, based on experiments and/or experience.
In general, a method option has to be as well described as a normative method. All necessary references
to the method in the main part of the standard and vice versa shall be given. Pre-normative validation
work has to be performed as well as for the main method. Results according to the alternatives or
options shall be equivalent.
All authorized options of one single analytical step shall be mentioned in the main document. If required,
they can be described in detail in an annex. It has to be clear that all the options are equivalent and can
be used.
A documented evaluation of any alternative step of a method is needed. This has to be provided by the
experts of the responsible working group before carrying out the interlaboratory trial.
The results of the method options/alternatives of the interlaboratory trial are pooled. No separate
evaluation of the results of the different options will be performed. The question, which of the options
was applied by a laboratory, is merely additional information for documentation of the interlaboratory
trial. The experts responsible for the interlaboratory trial have to evaluate the results and document
their decision.
6 Design and organization
6.1 Requirements for participation and call for participants
The number of participants has an influence on the reliability of the statistically calculated performance
data. A minimum of 24 outlier-free data obtained from a
...