CEN/TS 16800:2015

SLOVENSKI STANDARD
01-februar-2016
Smernica za validacijo fizikalno-kemijskih analiznih metod
Guideline for the validation of physico-chemical analytical methods
Anleitung zur Validierung physikalisch-chemischer Analysenverfahren
Lignes directrices pour la validation des méthodes d'analyse physico-chimiques
Ta slovenski standard je istoveten z: CEN/TS 16800:2015
ICS:
13.060.50 3UHLVNDYDYRGHQDNHPLþQH Examination of water for
VQRYL chemical substances
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TS 16800
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
December 2015
TECHNISCHE SPEZIFIKATION
ICS 13.060.50
English Version
Guideline for the validation of physico-chemical analytical
methods
Lignes directrices pour la validation des méthodes Anleitung zur Validierung physikalisch-chemischer
d'analyse physico-chimiques Analysenverfahren
This Technical Specification (CEN/TS) was approved by CEN on 14 March 2015 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 16800:2015 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Concept . 13
4.1 The concept of two validation levels . 13
4.2 First level - Validation 1 (V1) . 13
4.3 Second level - Validation 2 (V2) . 13
4.4 Method validation using a modular approach . 13
4.4.1 Validation modules . 13
4.4.2 Module A: Test method definition, documentation and general requirements . 13
4.4.3 Module B: Applicability domain and pre-validation . 14
4.4.4 Module C: Intra-laboratory performance . 14
4.4.5 Module D: Inter-laboratory performance . 14
4.5 Method classification . 15
5 Documentation of the validation process . 16
6 Validation 1 (V1): Intra-Laboratory Validation . 17
6.1 General . 17
6.2 Module A: Test method definition, documentation and general requirements . 17
6.3 Module B: Applicability domain and pre-validation . 18
6.4 Module C: Intra-laboratory performance . 18
6.4.1 General . 18
6.4.2 Bias . 18
6.4.3 Precision . 19
6.4.4 Calibration data and function . 20
6.4.5 Limits and application range . 21
6.4.6 Selectivity . 22
6.4.7 Robustness. 23
6.4.8 Measurement uncertainty . 23
7 Validation 2 (V2): Inter-Laboratory Validation . 23
7.1 General . 23
7.2 Method definition and description . 24
7.3 Module C: Intra-laboratory performance . 24
7.4 Module D: Inter-laboratory performance . 24
7.4.1 General . 24
7.4.2 General set-up of the inter-laboratory study . 25
7.4.3 The inter-laboratory study . 26
7.4.4 Statistical analysis and calculation of the results . 27
7.4.5 Evaluation of the fitness for purpose . 28
7.5 Documentation, publication and standardization . 31
Annex A (normative) Module A: Test method definition, documentation and general
requirements . 32
Annex B (normative) Module B: Applicability domain and pre-validation . 34
Annex C (normative) Module C: Intra-laboratory performance . 35
Annex D (normative) Module D: Requirements for an inter-laboratory validation study . 37
Annex E (informative) Structure and content of the documentation for a validation study
(V2) . 39
Annex F (informative) Robustness testing by systematic variation of influencing factors . 44
Bibliography . 46

European foreword
This document (CEN/TS 16800:2015) has been prepared by Technical Committee CEN/TC 230 “Water
analysis”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
Environmental monitoring of chemical substances is increasingly carried out within a European
framework, and there is concern about the comparability of data at the European level. In particular
methods used for the monitoring of substances with recent interest have often not been properly
validated either in-house (i.e. within a single laboratory) or at the international level.
These issues may be addressed by adopting a harmonized approach towards method development and
validation. The main objective of this document is to provide a common European approach to the
validation of chemical methods for the respective monitoring of chemical substances in a broad range of
matrices. Although the development of this approach was triggered by the needs for monitoring of
emerging pollutants, it is of general nature and can be applied to the measurement of a wide range of
substances in a variety of matrices.
This guidance takes into account the different requirements for the level of method maturity and
validation at different stages of the investigation or regulation of chemical substances.
In the case of a specific monitoring task, this protocol will guide the user through the following steps:
— classification of existing methods with respect to their status of validation, and the selection of the
appropriate validation approach;
— development of a method so as to extend its application; for example, if a method for determining a
required target compound in a particular matrix is available, but is not suitable for the same
compound in a different matrix of interest;
— the validation procedures to be carried out in order to effectively demonstrate the validation status
of a selected method according to the two approaches adopted.
Many (national and international) standards currently contain in their scope a statement like “this
method is applicable from a concentration level of xx µg/l or yy mg/kg dry matter”, without any
statement how this concentration level was established. When the limit of quantification (LOQ) is
evaluated using the procedure of this Technical Specification, there is a possibility that it does not meet
the lower limit of the claimed range.
1 Scope
This Technical Specification describes an approach for the validation of physico-chemical analytical
methods for environmental matrices.
The guidance in this document addresses two different validation approaches, in increasing order of
complexity. These are:
a) method development and validation at the level of single laboratories (intra-laboratory validation);
b) method validation at the level of several laboratories (between-laboratory or inter-laboratory
validation), with a focus on methods that are sufficiently mature and robust to be applied not only
by a few expert laboratories but by laboratories operating at the routine level.
The concept of these two approaches is strictly hierarchical, i.e. a method shall fulfil all criteria of the
first level before it can enter the validation protocol of the second level.
This Technical Specification is applicable to the validation of a broad range of quantitative physico-
chemical analytical methods for the analysis of water (including surface water, groundwater, waste
water, and sediment). Analytical methods for other environmental matrices, like soil, sludge, waste, and
biota can be validated in the same way. It is intended either for analytical methods aiming at substances
that have recently become of interest or for test methods applying recently developed technologies.
The minimal requirements that are indispensable for the characterization of the fitness for purpose of
an analytical method are: selectivity, precision, bias and measurement uncertainty. The aim of
validation is to prove that these requirements are met.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 78-2, Chemistry — Layouts for standards — Part 2: Methods of chemical analysis
ISO 5725, Chemistry — Layouts for standards — Part 2: Methods of chemical analysis
ISO 11352:2012, Water quality — Estimation of measurement uncertainty based on validation and
quality control data
ISO 21748:2010, Guidance for the use of repeatability, reproducibility and trueness estimates in
measurement uncertainty estimation
ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and
associated terms (VIM)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC Guide 99:2007 (VIM) and
the following apply.
3.1
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
[SOURCE: ISO 3534-2:2006, definition 3.2.7]
3.2
accuracy
closeness of agreement between a test result and the accepted reference value
[SOURCE: ISO 3534-2:2006, definition 3.3.1]
Note 1 to entry: The term accuracy, when applied to a set of test results, involves a combination of random
components (usually expressed by a precision measure) and a common systematic error or bias component
(usually expressed by a measure for trueness).
Note 2 to entry: The technical term "accuracy" should not be confused with the term ‘trueness’ (see definition of
"trueness").
3.3
analyte
substance to be analysed (chemical species or physical parameter)
Note 1 to entry: The quantity of an analyte is the measurand (3.15).
3.4
bias
difference between the expectation of a test result or measurement result and a true value
Note 1 to entry: Bias is the total systematic error as contrasted to random error. There may be one or more
systematic error components contributing to the bias. A larger systematic difference from the accepted reference
value is reflected by a larger bias value.
Note 2 to entry: The bias of a measuring instrument is normally estimated by averaging the error of indication
over an appropriate number of repeated measurements. The error of indication is the: "indication of a measuring
instrument minus a true value of the corresponding input quantity".
Note 3 to entry: In practice, accepted reference value is substituted for the true value.
[SOURCE: ISO 3534-2:2006, definition 3.3.2]
3.5
blank
sample or test scheme without the analyte known to produce the measured signal
Note 1 to entry: Use of various types of blanks enable assessment of which proportion of the measured signal is
attributable to the measurand and which proportion to other causes. Various types of blank are available (see
definition of reagent blank and blank sample).
3.6
calibration
operation that, under specified conditions, in a first step, establishes a relation between the quantity
values with measurement uncertainties provided by measurement standards and corresponding
indications with associated measurement uncertainties and, in a second step, uses this information to
establish a relation for obtaining a measurement result from an indication
Note 1 to entry: A calibration may be expressed by a statement, calibration function, calibration diagram,
calibration curve, or calibration table. In some cases, it may consist of an additive or multiplicative correction of
the indication with associated measurement uncertainty.
Note 2 to entry: Calibration should not be confused with adjustment of a measuring system, often mistakenly
called “self-calibration”, nor with verification of calibration.
[SOURCE: ISO/IEC Guide 99:2007, definition 2.39]
3.7
certified reference material
CRM
reference material, accompanied by documentation issued by an authoritative body and providing one
or more specified property values with associated uncertainties and traceabilities, using valid
procedures
[SOURCE: ISO/IEC Guide 99:2007, definition 5.14]
3.8
fitness for purpose
degree to which data produced by a measurement process enables a user to make technically and
administratively correct decisions for a stated purpose
3.9
intermediate precision
precision under intermediate precision conditions
[SOURCE: ISO 3534-2:2006, definition 3.3.15]
3.10
intermediate precision conditions
conditions where test results or measurement results are obtained with the same method, on identical
test/measurement items in the same test or measurement facility, under some different operating
conditions
Note 1 to entry: There are four elements to the operating condition: time, calibration, operator and equipment.
[SOURCE: ISO 3534-2:2006, definition 3.3.16 and ISO 11352:2012, definition 3.10]
3.11
limit of detection
measured quantity value, obtained by a given measurement procedure, for which the probability of
falsely claiming the absence of a component in a material is β, given a probability α of falsely claiming
its presence
Note 1 to entry: IUPAC recommends default values for α and β equal to 0,05.
Note 2 to entry: The abbreviation LOD is sometimes used.
Note 3 to entry: The term “sensitivity” is discouraged for ‘detection limit’.
[SOURCE: ISO/IEC Guide 99:2007, definition 4.18]
Note 4 to entry: The LOD is the lowest concentration of measurand in a sample that can be detected, but not
necessarily quantitated under the stated conditions of the test.
3.12
limit of quantitation
lowest concentration of a measurand that can be determined with acceptable precision under the stated
conditions of the test
3.13
reporting limit
specific concentration at or above the limit of quantification that is reported to the client with a certain
degree of confidence
Note 1 to entry: The reporting limit is often defined on a project-specific basis. If the reporting limit is set below
the limit of quantification by the client, method modification is required.
[SOURCE: ISO/TS 13530:2009, 4.4.7]
3.14
linearity
ability of the method to obtain test results proportional to the concentration of measurand
Note 1 to entry: The linear range is by inference the range of measurand concentrations over which the method
gives test results proportional to the concentration of the measurand.
[SOURCE: EURACHEM Guide]
3.15
measurand
quantity intended to be measured
Note 1 to entry: The specification of a measurand requires knowledge of the kind of quantity, description of the
state of the phenomenon, body, or substance carrying the quantity, including any relevant component, and the
chemical entities involved.
Note 2 to entry: In chemistry, “analyte”, or the name of a substance or compound, are terms sometimes used for
“measurand”. This usage is erroneous because these terms do not refer to quantities.
[SOURCE: ISO/IEC Guide 99:2007, definition 2.3]
3.16
measurement
process of experimentally obtaining one or more quantity values that can reasonably be attributed to a
quantity
[SOURCE: ISO/IEC Guide 99:2007, definition 2.1]
3.17
measurement uncertainty
non-negative parameter characterizing the dispersion of the quantity values being attributed to a
measurand, based on the information used
[SOURCE: ISO/IEC Guide 99:2007, definition 2.26].
3.18
outlier
member of a set of values which is inconsistent with the other members of that set
Note 1 to entry: ISO 5725-2 specifies the statistical tests and the significance level to be used to identify outliers
in trueness and precision experiments.
[SOURCE: ISO 5725-1:1994, definition 3.21]
3.19
precision
closeness of agreement between independent test results obtained under stipulated conditions
Note 1 to entry: Precision depends only on the distribution of random errors and does not relate to the true
value or the specified value.
Note 2 to entry: The measure of precision is usually expressed in terms of imprecision and computed as a
standard deviation of the test results. Less precision is reflected by a larger standard deviation.
[SOURCE: ISO 3534-2:2006, definition 3.3.4]
Note 3 to entry: „Independent test results“ means results obtained in a manner not influenced by any previous
result on the same or similar test object. Quantitative measures of precision depend critically on the stipulated
conditions. Repeatability and reproducibility conditions are particular sets of extreme conditions.
3.20
proficiency testing
evaluation of participant performance against pre-established criteria by means of interlaboratory
comparisons
[SOURCE: EN ISO/IEC 17043:2010, definition 3.7]
3.21
quality assurance
part of quality management focused on providing confidence that quality requirements will be fulfilled
[SOURCE: EN ISO 9000:2015, definition 3.3.6]
Note 1 to entry: A major part of quality assurance is quality control.
3.22
quality control
part of quality management focused on fulfilling quality requirements
[SOURCE: EN ISO 9000:2015, definition 3.3.7]
3.23
quantity
property of a phenomenon, body, or substance, where the property has a magnitude that can be
expressed as a number and a reference
[SOURCE: ISO/IEC Guide 99:2007, definition 1.1]
3.24
working range
interval, being experimentally established and statistically proved by the calibration of the method,
between the lowest and highest quantity possibly measured by the method
Note 1 to entry: The lowest possible limit of a working range is the limit of quantification of an analytical
method.
3.25
reagent blank
all reagents used during the analytical process (including solvents used for extraction or dissolution)
are analysed in isolation in order to check whether they contribute to the measurement signal
Note 1 to entry: The measurement signal arising from the measurand can then be corrected accordingly.
3.26
recovery
extent to which a known, added quantity of determinant in a sample can be measured by an analytical
system
Note 1 to entry: It is calculated from the difference between results obtained from spiked and unspiked aliquots
of sample, and is usually expressed as a percentage.
[SOURCE: ISO 6107-8:1993/Amd 1:2001-12]
3.27
reference material
RM
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 30:2015, definition 2.1.1, modified – Notes to entry have not been included.]
3.28
repeatability
precision under repeatability conditions, i.e. conditions where independent test results are obtained
with the same method on identical test items in the same laboratory by the same operator using the
same equipment within short intervals of time
[SOURCE: ISO 3534-2:2006, definition 3.3.5 and 3.3.6 , modified – These definitions were combined.]
3.29
reproducibility
precision under reproducibility conditions, i.e. conditions where test results are obtained with the same
method on identical test items in different laboratories with different operators using different
equipment
[SOURCE: ISO 3534-2:2006, definition 3.3.10 and 3.3.11, modified – These definitions were combined.]
3.30
residual
difference between the observed response and that predicted by a calibration function
3.31
robustness
measure of capacity of a procedure to remain unaffected by small, but deliberate variations in method
parameters and provides an indication of its reliability during normal usage
3.32
sample
totality of a homogeneous analysis material with an identical composition or quality (similar to term
batch)
[SOURCE: ISO/TS 20612:2007, definition 3.3]
3.33
blank sample
matrix with no measurand
Note 1 to entry: They are difficult to obtain but such materials are necessary to give a realistic estimate of
interferences that would be encountered in the analysis of test samples.
3.34
selectivity
ability of a method to determine accurately and specifically the measurand of interest in the presence of
other components in a sample matrix under the stated conditions of the test
3.35
sensitivity
change in the response of a measurand divided by the corresponding change in the stimulus
3.36
traceability
property of a measurement result whereby the result can be related to a reference through a
documented unbroken chain of calibrations, each contributing to the measurement uncertainty
[SOURCE: ISO/IEC Guide 99:2007, definition 2.41]
3.37
trueness
closeness of agreement between the average value obtained from a large series of test results and an
accepted reference value
Note 1 to entry: In the present document, trueness will be expressed in terms of bias.
Note 2 to entry: Trueness should not be confused with the term ‘accuracy’ (see definition of "accuracy").
3.38
validation
verification, where the specified requirements are adequate for an intended use
[SOURCE: ISO/IEC Guide 99:2007, definition 2.45]
Note 1 to entry: This process is used to asses that a method is fit for its intended purpose. It includes:
— establishing the performance characteristics, advantages and limitations of a method and the identification of
the influences which may change these characteristics, and the extent of such changes;
— a comprehensive evaluation of the outcome of this process with respect to the fitness for purpose of the
method.
4 Concept
4.1 The concept of two validation levels
The requirements for methods used for monitoring of chemical measurands depend on:
— the extent of the intended or requested monitoring activity; and
— the potential of the available methods that may be used for monitoring a specific substance (group).
In some cases, fully developed methods used by routine laboratories may already exist. More
frequently, in the case of new substances or newly developing methods there will be a lack of
information on the extent to which the methods have been fully developed and validated. In order to
cover most eventualities, two distinct (and hierarchical) levels of method validation are described in
this document.
4.2 First level - Validation 1 (V1)
Validation 1 addresses method development (new development or extension of an existing method
application to new matrices) and method validation at the intra-laboratory level. The endpoint of
Validation 1 is a method with a complete internal validation for the intended purpose at the level of a
single laboratory. The endpoint of Validation 1 is identical with the starting point of Validation 2.
4.3 Second level - Validation 2 (V2)
Validation 2 addresses method validation at the inter-laboratory level. The main issue is to demonstrate
that the method possesses sufficient inter-laboratory performance and is applicable for use at the level
of routine laboratories. This also comprises the development and control of key aspects of method
documentation and method usability.
NOTE If a method has successfully passed the Validation 2 procedures, it is usually suitable for
standardization at the European level.
4.4 Method validation using a modular approach
4.4.1 Validation modules
The goal of any validation activity is to demonstrate the applicability of an analytical method to the
intended purpose. Any analytical method ideally provides reliable and comparable data when carried
out on similar samples, independent from external modifications of operating conditions, e.g. different
laboratories or operators. This fitness-for-purpose shall be demonstrated through experimental, well-
documented evidences. This comprises a set of general principles and criteria that are applicable to
physico-chemical test methods. These principles and criteria are organized in four modules (A to D).
This Technical Specification follows a hierarchical approach with respect to the two validation levels.
This means that for second level validation (V2) all requirements and criteria of the first level validation
(V1) shall be fulfilled.
4.4.2 Module A: Test method definition, documentation and general requirements
The aim of Module A is to check before starting experimental investigation, that the laboratory has
extensively taken into account all requirements for performance of the intended method. This step is
essentially documental.
It is essential that an unambiguous definition of the method, the intended scope of application, its
scientific basis, its purpose and a statement about the need for the test method, and criteria for
acceptable method performance be documented. This should also include, if known, a description of the
relationship (mechanistic or empirical) between the measurand and the response in the investigated
system, e.g. electronic signal. Furthermore, a detailed documented protocol for the method should be
available. This should include a description of all materials and reagents, a description of what is to be
measured, and how this is to be carried out.
The criteria to be fulfilled in Module A at validation level V1 and at level V2 are different. They are
presented in Table 1. A detailed description and structure for Module A is given in Annex A.
4.4.3 Module B: Applicability domain and pre-validation
Experimental investigation starts with Module B.
Test methods may be developed, optimized and validated for measuring a substance or an operationally
defined parameter within a specified scope. This scope may include restrictions on the sampled media,
the matrix, the concentration range of the measurand, and other limits of the scope of application. The
suitability of the method drafted according to Module A is investigated on the whole scope in module B.
It implies that, when an extension of the scope of a validated test method is to be investigated, Module B
shall entirely be carried out on the additional parts of the new scope. The criteria to be fulfilled in
Module B at validation level V1 and at level V2 are identical. They are presented in Table 1. A detailed
description and structure for Module B is given in Annex B.
4.4.4 Module C: Intra-laboratory performance
The basic performance characteristics of the test method within one laboratory should be determined
in order to evaluate its reliability, relevance and limitations. These performance characteristics may
include (among others) parameters such as precision, bias, selectivity and traceability.
Module C is related to validation level V1. A detailed description and structure for Module C is given in
Annex C.
4.4.5 Module D: Inter-laboratory performance
Module D is related to validation level V2. Validation level V1 shall be completed before entering
validation level V2 investigations.
In order to be applicable for large-scale European-wide purpose, a test method for pollutants shall show
sufficient inter-laboratory performance at the level of routine laboratories. Therefore it is essential that
a test method has a high degree of robustness and usability. Furthermore, the completeness and clarity
of the method description (protocol) are more important than when a method is to be tested within a
single laboratory. The protocol shall be accompanied by detailed control procedures and should not be
open to misinterpretation.
The principal tool used to evaluate the inter-laboratory performance of a method is an inter-laboratory
comparison involving the analysis of identical test items across all participating laboratories. These
inter-laboratory studies are usually designed with the aim of sorting the effects of inter- and intra-
laboratory variation on the measures used to characterize and evaluate the performance characteristics
of the test method. Appropriated tools and procedures to establish the value of measures for inter-
laboratory performance criteria can be found in ISO 5725-2, ISO 5725-5 and ISO 13528. Validation
studies carried out as a part of European standardization activities are examples of this level of
validation.
A detailed description and structure for Module D is given in 7.4 and Annex D.
4.5 Method classification
In order to select the appropriate validation protocol, potential candidate methods shall be classified
according to their level of maturity and validation. This may be considered as an abridged version of a
retrospective validation study. Guidance on method classification with respect to the two validation
levels is given in this section. However, this should only be used to provide a quick and approximate
estimate of the maturity and validation status of the method.
If a classified method has been subject to the appropriate validation protocol, detailed work on either
retrospective or prospective validation studies may reveal some inadequacies within the method. In
this case it may be necessary to investigate certain modules of the lower validation level. This process
may eventually lead to a downgrading of the method by a validation level.
Table 1 provides guidance on how to classify existing methods with respect to the two levels of
validation. As a result of the classification, the user should be directed to the appropriate validation
protocol. The validation modules shall be used to identify the criteria that shall be fulfilled at the
endpoint of each validation protocol. If a method fails to fulfil one or more mandatory criteria assigned
to the modules of the respective validation level, the method should be placed in the lower level of
validation maturity. In Table 1, a ’+’ indicates that the respective criterion shall be fulfilled by the
candidate method in order to be considered as validated at the respective level, and ‘(+)’ means that the
fulfilment of this criterion is not mandatory, but is, at least, highly recommended.
Table 1 — Method classification - requirements for the two validation levels
Criteria for the type of test method to be classified Required at validation level
V1 V2
Module A – Test method definition and documentation
Definition of need + +
Purpose
Development of knowledge + +
Regulatory purpose (+)
Scientific basis
Defined mechanism/effect + +
Scientific proof of relationship between a measured signal + +
or effect and the measurand in the investigated system
Documentation (Protocol)
with sufficient information for a researcher with special + +
expertise to use the method
with detailed information sufficient for a trained analyst +
according to ISO 78-2 (standard-like) +
with detailed control procedures and performance criteria +
a
statistics available (record of survey of performance +
characteristics)
Dissemination
Grey literature + +
Peer-reviewed publication (+)
Criteria for the type of test method to be classified Required at validation level
V1 V2
National, European or International Standard (+)
Module B – Applicability domain
Applicability
to the measurand + +
to the matrix of interest + +
to the environmental compartment of interest + +
Modules C and D – Intra- and Interlaboratory Performance
Matching the performance characteristics required (e.g. from the
regulator or other ‘ordering’ party)
shown by one laboratory only + +
shown by inter-laboratory study +
+ indicates that the respective criterion shall be fulfilled by the candidate method in order to be considered as validated at the
respective level
(+) means that the fulfilment of this criterion is not mandatory, but is, at least, highly recommended
a
In the early stages of the implementation of a newly developed method, the laboratory has not enough data to conduct
statistical evaluation. Nevertheless, the laboratory should start collecting data to be able to have enough for V2 level validation.
5 Documentation of the validation process
All validation steps shall be documented. In order to facilitate this process and to ensure a common
documentation format, templates for documentation (in the form of tables) are presented in the
respective validation protocols (see Annex A to Annex D). A harmonized set of documentation
templates ensures that the documentation of the validation process is comprehensible and traceable.
Such templates also enable a quick evaluation of the validation status of the method or the identification
of gaps that need to be bridged.
Four different templates shall be used for documentation of the validation process. These templates
correspond to the four validation modules A, B, C and D which are defined and described in Annexes A
to D. Therefore, the extent of documentation and the number of templates to be completed depends on
the level of validation a method has passed (see Table 2).
Table 2 — Method documentation - requirements for each validation level
Documentation required Method validated at level
V1 V2
Module A (Template Table A.1) + +
Module B (Template Table B.1) + +
Module C (Template Table C.1) + +
Module D (Template Table D.1)  +
Module A and Module B shall contain general information on the method (e.g. its definition, and its
applicability domain), whereas Module C and Module D correspond to the specific validation tasks
carried out at the level of V1 and V2, respectively. The documentation templates (at least those
corresponding to modules C and D) may therefore also be used as a preview of the validation tasks
which shall be carried out at the respective validation level.
The documentation of the method validation process may not be confused with the method description,
although some of the information in the two types of documents may be similar or even identical.
Information from Module A (Table A.1) and Module B (Table B.1) can be used to compile the
information for the method description. At the V1 level, the information given in modules A and B,
together with an appropriate reference to the (scientific) literature, may be sufficient as method
description, but at the higher level the requirements for the description of the method increase.
Therefore, a more comprehensive set of criteria for the method description has been compiled for the
V2 level, and should be followed in the preparation of the method description.
If a method enters a higher validation level, the information in modules A and B may need to be
updated, because more information has been or needs to be gathered on specific requirements or
abilities of the method, or requirements for the method and its performance characteristics may
change. Therefore, a method successfully validated up to the V2 level will usually be accompanied by a
set of modules recording the history of the validation process of this particular method.
6 Validation 1 (V1): Intra-Laboratory Validation
6.1 General
The Validation V1 protocol covers the scenario where for a given (group of) measurand(s) a method is
available but
— is either not applicable to the matrices or compartments of interest (pre-validation), or
— its suitability for the intended purpose with respect to certain performance criteria has not been
sufficiently tested and proven.
Protocol V1 describes guidance for the intra-laboratory validation of methods, parameters and criteria
that are needed to establish a chemical method at the intra-laboratory level.
The key performance parameters that require attention during the intra-laboratory validation vary
according to the measurement requirement and method. Nevertheless, commonly important
parameters are listed in 6.4.1. These are based on the earlier described validation Module A (test
method definition, documentation and general requirements), Module B (applicability domain and pre-
validation), and Module C (intra-laboratory performance).
Module A focuses on the requirements of the method a
...