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Validation of Measurement Procedures that Include Sampling (1st Ed)

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Published: Wednesday, 18 December 2024 01:45

A supplement to:
“The Fitness for Purpose of Analytical Methods”
“Measurement Uncertainty arising from Sampling”

Vampis converge txt outGuidance is given on how to validate a measuring procedure that includes the primary sampling (VaMPIS). It is a supplement to existing Eurachem guidance on “The Fitness for Purpose of Analytical Methods” and “Measurement Uncertainty arising from Sampling”. The overall aim is to extend the concept of ‘validation of a measurement procedure’ beyond the validation of the analytical method (or procedure) alone, in order to include the primary sampling (and physical sample preparation) within the validation process.

Ideally, VaMPIS can be applied to validate the whole measurement procedure simultaneously. Alternatively, VaMPIS can be applied sequentially by using an analytical procedure that has already been validated for this purpose in isolation, but then extending it to include the sampling step.

The key characteristic that enables validation of both the sampling and the analytical procedures is the measurement uncertainty, when supported by the performance characteristics that apply to the analytical procedure, which are already described in the Fitness for Purpose guide.

Two worked examples are provided to demonstrate how VaMPIS can be applied to both ex situ analysis in a laboratory of an extracted sample, and also to in situ analysis made ‘in the field’, without extracting a physical sample. Guidance is also given on the management and QC issues that are needed in order to integrate the sampling and the analytical steps, which have previously usually not had a unified and coordinated approach to data quality.

Availability

This supplementary guidance is available in the following languages:

Citation

This publication should be cited* as:
M. H. Ramsey, P. D. Rostron, F. C. Raposo (eds.) Eurachem/EUROLAB/CITAC/Nordtest/AMC Guide: "Validation of Measurement Procedures that Include Sampling", Eurachem (2024).  Available from http://www.eurachem.org"

*Subject to journal requirements

Translations

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Accreditation for Microbiological Laboratories (2023)

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Published: Tuesday, 23 May 2023 15:51
Microbiology plate. Original image from CDC via unsplash.com

Contents

This Eurachem Guide has been produced by an ad hoc Eurachem Working Group. This third edition of Accreditation for Microbiological Laboratories is a revision of the second edition published in 2013. The first edition from 2002 was produced by a joint EA/Eurachem Working Group.

The aim of this guide is to provide microbiological laboratories with guidance on how to fulfil the requirements of ISO/IEC 17025. The content, however, should also be of use to organisations seeking accreditation or certification against the requirements of standards such as ISO 15189, GLP (Good Laboratory Practice), GMP (Good Manufacturing Practice), and GCP (Good Clinical Practice)). Specific national regulations may override the guidance given in this document. The Guide will also provide useful information for laboratories that wish to establish a quality management system but are not seeking formal recognition.

The principal changes in the third edition are:

  • update on recent trends in microbiology, e.g. PCR (polymerase chain reaction) techniques for the detection of microorganisms;
  • addition of a list of abbreviations and symbols;
  • addition of a section on risk-based thinking;
  • updated sections on method verification and validation to reflect current ISO standards;
  • references to the use of a decision rule;
  • updated Annex A on terminology relevant to microbiology;
  • new Annex C on reporting confidence intervals;
  • new Annex D on estimation of uncertainty from sampling;
  • the order of sections in adherence with ISO/IEC 17025:2017.

 

Availability

This third edition is currently available in English and can be downloaded at no cost from the link below:

Download the guide in English [pdf, 272 kB] (2023-05-23)+

+ Date of publication on this site

Translations

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Citation

This guidance should be cited* as:

“B Magnusson and K C Tsimillis (eds.) Accreditation for Microbiological Laboratories (3rd ed. 2023). ISBN 978-91-519-6581-9. Available from www.eurachem.org.”

*Subject to journal requirements

Previous versions

The second edition of this Guide can be found in the publication archive on this website.

 

 

 

 

Assessment of performance and uncertainty in qualitative chemical analysis

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Published: Wednesday, 10 November 2021 22:54

Introduction

Mass spectrometric identification of pesticide in lettuceMany decisions with socio-economic or individual impact depend on qualitative analysis, including decisions related to food safety, clinical diagnosis, and forensic evidence, are based primarily on qualitative, rather than quantitative, chemical analysis. Qualitative analysis is analysis that returns a classification rather than a numerical value, such as the identity of a chemical substance, the type of plastic of a microparticle, the potential source of an oil spill, the presence of a banned sports doping substance, or the presence of accelerant in fire debris. Sometimes, such classifications rely solely on qualitative tests; others may use measurement results (such as line frequencies in a spectrum) to reach a conclusion.

Qualitative analysis, like quantitative analysis, needs to be demonstrably reliable. Part of the purpose of the guide is accordingly to show how the performance of a qualitative analysis procedure can be quantified to ensure its fitness for purpose. Practical difficulties and limitations in reliable quantification of low false result rates are discussed, and recommendations are made for checking the validity of these analyses. Brief recommendations are also made for ensuring that any measurements undertaken in the course of a qualitative analysis are reliable.

Although laboratories accredited following the ISO/IEC 17025 standard are not currently required to express qualitative analysis results with uncertainty, the guide provides some metrics that can be used to convey the level of confidence in conclusions from qualitative analysis. In addition, the guide provides suggestions for reporting results with an indication of confidence if desired. 

This guide does not make recommendations on whether or not laboratories should routinely report information on the confidence, or uncertainty, associated with qualitative analysis results. Nevertheless, an understanding of performance, or of the uncertainty associated with a qualitative analysis result, can help laboratories to better advise customers; it can also help to identify quality improvements or determine (for example) whether additional confirmatory tests might be needed.

This Eurachem/CITAC guide accordingly aims to provide some tools to help improve the quality of qualitative analysis and of their interpretation, to make sure that interests dependent on these analyses are well protected.

Content of the guide

This guide includes information on 

  • The nature and relevance of qualitative analysis.
  • Different types of qualitative analysis - for example, those that depend on qualitative tests alone, and others that use quantitative information to come to a conclusion.
  • Experimental and other strategies for estimating false response rates, which are fundamental to establishing reliability.
  • Expressions of confidence in qualitative analysis.
  • Reporting qualitative analysis results.
  • Examples showing how false response rates and other metrics can be determined.
  • The statistical basis for some important measures of confidence in a qualitative result.

 

Availability

The guide may be downloaded from this website at no cost.

* First published 2021-11-11. Publication dates above are dates of file publication on this website.

Translation

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Citation

This guidance should be cited* as
"R Bettencourt da Silva and S L R Ellison (eds.) Eurachem/CITAC Guide: Assessment of performance and uncertainty in qualitative chemical analysis. First Edition, Eurachem (2021). ISBN 978-0-948926-39-6.
Available from www.eurachem.org."

*Subject to journal requirements.

Previous editions

There are no earlier editions of this Guide.

Use of uncertainty information in compliance assessment. (2nd ed. 2021)

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Published: Thursday, 29 April 2021 14:17

Content

Stringent and relaxed acceptance 230x200In order to decide whether a result indicates compliance or non-compliance with a specification, it is necessary to take into account the measurement uncertainty associated with the result. This guide provides guidance on how uncertainty may be taken into account in deciding compliance with a limit.

The guide is applicable to decisions on compliance with regulatory or manufacturing limits where a decision is made on the basis of a decision rule, together with a measurement value and the associated measurement uncertainty.

The guide includes a discussion and general recommendations, including the use of "guard bands" to improve the probability of correct acceptance or correct rejection. This is followed by more detailed guidance on establishing rules for interpretation and by several examples.

This second edition has been amended to take into account the developments in other international guides and Standards, including ILAC G8, "Guidelines on Decision Rules and Statements of Conformity" and JCGM 106, "Evaluation of measurement data – The role of measurement uncertainty in conformity assessment".

Major changes in this second edition are:

  • the idea of an acceptance limit is introduced;
  • decision rules that provide for conditional or inconclusive results are introduced (sometimes called “non-binary” decision rules);
  • use of the lognormal distribution is introduced for some asymmetric cases;
  • an Annex has been added to introduce the ideas of "global" and "specific" risks.

Availability

The guide may be downloaded from this website at no cost.

* Publication dates are dates of publication on this website.

Translation

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Note: The First edition of this guide is available in English, Farsi and Portuguese.

Citation

This guidance should be cited* as
"A. Williams and B. Magnusson (eds.) Eurachem/CITAC Guide: Use of uncertainty information in compliance assessment (2nd ed. 2021). ISBN 978-0-948926-38-9.  Available from www.eurachem.org."

*Subject to journal requirements.

Previous editions

Earlier editions of this guide are available in the publication archive on this website.

Blanks in method validation

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Published: Monday, 15 July 2019 23:07

A Supplement to the Eurachem Guide "The Fitness for Purpose of
Analytical Methods"

Contents

Cover of 'blanks' supplementBlanks are an important tool and are used in the determination of most performance characteristics during a validation process. They are also often included in each analytical run during routine use of the measurement procedure. There are many different types of blanks and the analyst must consider which blanks to include during preparation of the validation plan.

The aim of this supplement is to describe the different types of blanks which may be used during method validation and to provide guidance for situations where it may be difficult to obtain a suitable blank matrix. It is intended to be used in conjunction with "The Fitness for Purpose of Analytical Methods - A Laboratory Guide to Method Validation and Related Topics (3rd ed.)"

Availability

This supplementary guidance is available in the following languages:

Citation

This publication should be cited* as:
"H. Cantwell (ed.) Blanks in Method Validation - Supplement to Eurachem Guide The Fitness for Purpose of Analytical Methods, (2nd ed. 2025). Available from http://www.eurachem.org"

*Subject to journal requirements

Translations

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

The previous edition of this supplement is available in a number of translations. Please see previous editions here.

 

Previous Editions

The first edition of this supplement, and its translations, is available here.

Planning and Reporting Method Validation Studies

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Published: Monday, 15 July 2019 23:07

A Supplement to the Eurachem Guide "The Fitness for Purpose of
Analytical Methods"

Contents

Cover of method validation 'Planning' supplementPlanning is an essential stage in the validation process. Before starting any experimental work, the aim should be to have a clear plan for the entire validation study. This should cover the performance characteristics that will be studied, the target value for each performance characteristic, the materials that will be analysed, the level of replication and order of the experiments, any statistical analysis that will be used, and how the method will be judged as being fit for purpose.

This supplement provides guidance on the planning and reporting of validation studies. The document is structured in the form of a template which can be used to assist with planning the evaluation of the chosen performance characteristics. The template is structured such that once the experimental work has been completed, the document can be easily converted into a validation report. The supplement also contains a checklist to assist with validation planning.

This supplement is intended to be used in conjunction with "The Fitness for Purpose of Analytical Methods - A Laboratory Guide to Method Validation and Related Topics (3rd ed.)

Availability

This supplementary guidance is available in the following languages:

 

Citation

This publication should be cited* as:
“V. Barwick (ed.), Planning and Reporting Method Validation Studies – Supplement to Eurachem Guide on the Fitness for Purpose of Analytical Methods (2nd ed. 2025). Available from http://www.eurachem.org"

*Subject to journal requirements

Translations

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

The previous edition of this supplement is available in a number of translations, see previous editions below.

 

Previous Editions

The first edition of this supplement, and its translations, is available here.

Guide to Quality in Analytical Chemistry - 3rd edition (2016)

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Published: Wednesday, 25 January 2017 00:00

Content

QAC 2016 cover 180hThe aim of this guide is to provide laboratories with guidance on best practice for the analytical operations they carry out. The guidance covers both qualitative and quantitative analysis carried out on a routine or non-routine basis. A separate guide covers research and development work (Quality Assurance for Research and Development and Non-routine Analysis,1998 ).

This third edition is a revision of the CITAC/Eurachem Guide published in 2002. The 2002 edition was developed from CITAC Guide 1 (which in turn was based on the Eurachem/WELAC Guide). The third edition reflects changes that were introduced with the publication of the 2005 version of ISO/IEC 17025. The terminology has also been updated to take account of ISO/IEC 17000:2004, ISO 9000:2015 and the 3rd edition of the International Vocabulary of Metrology – Basic and general concepts and associated terms (JCGM 200:2012 – VIM).

The Guide focuses on the requirements of ISO/IEC 17025, however the content should also be of use to organisations seeking accreditation or certification against the requirements of standards such as ISO 15189 or ISO 9001, or compliance with the Principles of Good Laboratory Practice

Availability

You may download the guide from this website at no cost (pdf, 960 kB).

Translations

Versions are currently available in

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Publication date

This third edition was approved for publication in December 2016 and first published on this website on 25 January 2017.

Citation

This publication should be cited* as:

“V. Barwick (Ed), Eurachem/CITAC Guide: Guide to Quality in Analytical Chemistry: An Aid to Accreditation (3rd ed. 2016). ISBN 978-0-948926-32-7. Available from www.eurachem.org.”

*Subject to journal requirements

Setting and Using Target Uncertainty in Chemical Measurement

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Published: Monday, 28 September 2015 03:54

Contents

The Eurachem/CITAC Measurement uncertainty and traceability working group has prepared this Guide to as part of a sequence of guidelines that aims at promoting the production of measurement results that are traceable to an adequate reference and are reported with reliable and sufficiently low uncertainty for the intended use of the measurement. These features are essential for the adequate interpretation of the measurement result which is discussed in the Eurachem/CITAC guide, ‘Use of uncertainty information in compliance assessment’.

This document discusses how to set a maximum admissible uncertainty, defined in the third edition of the International Vocabulary of Metrology as the “target uncertainty”, to check whether measurement quality quantified by the measurement uncertainty is fit for the intended purpose.

Target MU 178pxThis guideline is applicable to analytical fields where the target uncertainty is not set by the regulator or the client, or where a minimum difference of the studied parameter in the same or different items must be detected in R&D work. This guide discusses how to set the target uncertainty for process development and for applied or fundamental research using information about the smallest difference or system trend that must be distinguished in a reliable way.

This guideline can also be useful for authorities and stakeholders that feel the need to define or upgrade criteria for measurements quality. The setting of target values for the so called conventional performance characteristics (precision, trueness, etc.) can miss the control of important uncertainty components included in sound uncertainty evaluations.

The document fills a gap in the current list of guidance for measurements in chemistry and can contribute to ensuring measurements play their role in the management of socio-economic interests and in the technological and scientific developments of society.

Availability

You may download the Guide from this website at no cost. 

NB: See also "Comments and errata" below.

Translations

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Recommended citation

This publication should be cited* as: “R. Bettencourt da Silva, A. Williams (Eds), Eurachem/CITAC Guide: Setting and Using Target Uncertainty in Chemical Measurement, (1st ed. 2015). ISBN: 978-989-98723-7-0. Available from www.eurachem.org.”
*Subject to journal requirements

Approval and publication

This guide was approved for publication** by the Eurachem GA in May 2015 and first published on this website on 2015-09-28.
**Subject to minor comments

Comments and errata

Since publication of the Guide in 2015, a number of minor typographical issues have been identified. Although not sufficient to justify revision and re-issue of the complete Guide and translations, the Measurement Uncertainty and Traceability WG have prepared a list of comments and corrections for reader information. These are likely to be implemented in future editions.

The Fitness for Purpose of Analytical Methods (2025)

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Published: Thursday, 16 October 2014 00:00

Full title

The Fitness for Purpose of Analytical Methods: A Laboratory Guide to Method Validation and Related Topics: Third edition (2025)

Quick links:

Introduction

Frontcover Validation Guide 90

This guide was first issued in 1998 and the second edition published in 2014. Over the years it has been one of the most popular of the Eurachem guides. Since the release of the first edition, however, there have been many changes in terminology, working practices, reference documents and requirements. This third edition, produced by the Eurachem Method Validation Working Group, forms a thorough revision of the 2014 edition.

This third edition includes a section on sampling and sample handling as ISO/IEC 17025:2017 introduced a focus on sampling associated with the testing or calibration being carried out by the laboratory and further guidance on assessing the calibration function has been included. The Guide is also now supported by a number of supplementary guidance documents – please see the section on supplementary guidance below.

Contents

This third edition includes guidance on:

  • The importance of fitness for purpose;
  • The concept of method validation and verification;
  • How a method validation or verification study should be performed and how much should be done;
  • Sampling and sample handling in relation to method validation;
  • A thorough explanation of the various validation parameters (performance characteristics) and related topics;
  • Follow-up on the validation study (reporting, use of performance data in Internal Quality Control);
  • Documentation of analytical methods.

 

Annexes also describe the statistical basis of detection limits and analysis of variance for precision studies, and add a check list to aid users in selecting and determining the validity of a test kit.

In preparing this guidance, the Working Group has aimed at the right balance between giving a solid theoretical background for method validation studies and providing practical guidelines on how to plan, perform and evaluate such studies in the laboratories.

The approach is generic in the sense that the Guide does not focus on particular fields of application (food, environment, pharmaceuticals etc.). However, the guide includes references to a number of specific guides in fields where different practices have been developed and become common.

The guide also includes a full bibliography. Further literature references on method validation can be found in the section "Validation of analytical methods" in the Reading list on this website.

Availability

You can download the Guide here at no cost:

The second edition of this Guide is available in a number of translations. For details see previous editions below.

Citation

This publication should be cited* as:
"H. Cantwell (ed.) Eurachem Guide: The Fitness for Purpose of Analytical Methods – A Laboratory Guide to Method Validation and Related Topics, (3rd ed. 2025). Available from http://www.eurachem.org"

*Subject to journal requirements

Supplementary guidance

The supplementary guidance below gives additional guidance on method validation topics:

  • Planning and reporting method validation studies. This supplement is in the form of a template which can be used to assist with planning the evaluation of the chosen performance characteristics
  • Blanks in method validation. This short supplement describes the different types of blanks which may be used during method validation and provides guidance for situations where it may be difficult to obtain a suitable blank matrix.

Translations

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.

Previous version

The 2014 edition of this guide can be found here for reference.

 

Quality Assurance for Research and Development and Non-routine Analysis (1998)

Details
Published: Saturday, 10 July 2010 22:16

Contents

This guide, produced by a joint Eurachem/CITAC working party representing industrial, academic, and governmental interests, promotes and describes the concepts of quality assurance in the non-routine environment. The guide promotes a nested approach to quality assurance, dealing with it at a general organisational level, a technical level and a project specific level. It is intended to promote the use of QA as an effective tool for establishing and maintaining quality in R&D and non-routine operations. It does not seek to set criteria for accreditation of R&D although there is a section describing various methods for third party assessment of quality systems. The guidance may form the basis on which accreditation criteria can be set in the future. The guidance is intended to complement the existing CITAC guide (CG1) which describes QA in the routine environment. It is primarily directed towards analytical chemistry establishments but is, in principle, applicable to other sectors. An extensive bibliography is included.

Availability

The English language version (edition 1.0 1998) is available from the UK National Measurement System Chemical and Biological Metrology programme.

Download the guide from this website (new window) (pdf, 203 kB).

Translations

A German language version can be downloaded from the Eurachem/DE website documents page. (Opens new Browser window).

Translation into other languages is permitted for members of Eurachem. Other offers of translation should be directed to the Eurachem Secretariat for permission. The Eurachem policy on maintenance and development of Eurachem guidance, available on the Policies page, gives further information on translation.