65) The Committee recalled that the last session had agreed to consider the next draft of the IUPAC Harmonized Guidelines for the In-House Validation of Methods of Analysis when it became available. It had also agreed that the Delegation of the Netherlands would prepare a discussion paper on the characteristics of in-house validated methods for consideration by the next session.
66) The Committee agreed that it was preferable to use the term “single-laboratory validation” instead of “in-house validation” as proposed by the Delegation of the Czech Republic.
67) The Delegation of the Netherlands recalled that this question was essentially relevant for the determination of residues of pesticides and veterinary drugs, as relatively few collaboratively tested methods were available, and proposed the following recommendations for consideration by the Committee: to recognize the use of single laboratory validation for Codex purposes; to adopt criteria for in-house validated methods for Codex purposes; and to adopt the guidelines prepared by FAO/IAEA/AOAC for this purpose.
68) The Delegation of the United Kingdom indicated that the IUPAC Guidelines provided guidance on in-house validation but that it should not generally replace collaborative testing, and pointed out that two separate issues should be considered by the Committee: in-house validation, and the use of proficiency testing. The Delegation also drew the attention of the Committee to the examples presented in Annexes II and III as reflecting the practical experience of the United Kingdom in this area.
IUPAC Guidelines
69) The Committee noted that the Guidelines were not yet published in their final form by IUPAC, and therefore it was not possible to propose their adoption by reference at the present session.
70) The Observer from AOAC indicated that AOAC did not harmonize yet with the approach of the IUPAC Guidelines as they did no provide practical guidance on how to proceed with single laboratory validation. This view was supported by some delegations. The Delegation of the United Kingdom pointed out that the IUPAC Guidelines were intended as an overarching document rather than a detailed manual for food laboratories, and invited governments and international organizations to provide their comments to IUPAC.
71) The Delegation of Ireland informed the Committee that the EURACHEM Guide “Fitness for purpose of analytical methods. A Laboratory Guide to method validation and related topics” could provide useful guidance for food laboratories on single-laboratory validation. The Committee noted that NMKL had also established a procedure on in-house method validation and that NMKL had recently published guidelines on how to use certified reference materials: NMKL Procedure No. 9 (2001) Evaluation of Results Derived from the Analysis of Certified Reference Materials.
72) The Delegation of the United States proposed to reword the end of the second paragraph in section 4.4 Method and Laboratory Effects to the effect that ”the Horwitz function deviates at concentrations lower than about 120 ppb”.
Requirements for single-laboratory validation
73) The Committee had an exchange of views on the criteria proposed in the working document (page 2).
74) The Delegation of Germany, supported by other delegations and observers, expressed the view that the use of single-laboratory validation should not be restricted to multi-residue methods and that this recommendation should be revised (paragraph 8a). Some delegations pointed out that this problem was more general as laboratories had to develop new methods to detect substances which posed a hazard to health for food control purposes, such as dioxins or contaminants in contact material.
75) The Delegation of Germany also pointed out that the recommendations might be in contradiction with the criteria approach already approved by the Committee, especially as in the future certain methods might be presented only as criteria. The Committee agreed that these points should be addressed further in the revision of the “Requirements” section.
Relationship with the CCPR and CCRVDF
76) The Representative of FAO/IAEA informed the Committee that the lectures presented at the AOAC/FAO/IAEA/IUPAC International Workshop on Principles and Practices of Method Validation (4-6 November 1999) had been published in scientific literature[14], including the Guidelines for Single Laboratory Validation of Analytical Methods for Trace-Level Concentrations of Organic Chemicals, which were subsequently finalized by the FAO/IAEA/AOAC Consultation (8-11November 1999).
77) The Representative drew the attention of the Committee to the need for a harmonized approach to single/laboratory validation in the areas of veterinary drug residues and pesticide residues and stressed the importance of the work of FAO/IAEA in this area. The Delegation of the Netherlands proposed to forward the Guidelines to the CCPR and CCRVDF.
78) The Delegation of Sweden recalled that under part (g) of its terms of reference the Committee could make general recommendations to other committees on procedures and protocols, such as the IUPAC Guidelines, even when those committees were responsible for the development of their own methods.
79) The Secretariat confirmed that the CCMAS could address general recommendations on methodology to all other Committees, and that would apply to the IUPAC Guidelines. However it was not within its mandate to consider and make recommendations on a document covering exclusively chemical residues, such as the FAO/IAEA/AOAC Guidelines mentioned above.
80) The Secretariat also recalled that the usual practice for UN Agencies was to distribute the reports of expert consultations to Codex Committees when the recommendations put forward by these consultations required specific consideration by the Committees. This had been the case for example with the 1997 FAO/IAEA Consultation on Validation of Analytical Methods for Food Control[15] and was standard practice for FAO/WHO Consultations. According to the usual procedure, it was expected that the next sessions of the CCPR and the CCRVDF would have the opportunity to consider the reports of both the AOAC/FAO/IUPAC/IAEA Workshop and the FAO/IAEA/AOAC Consultation including the Guidelines, when distributed by FAO/IAEA.
81) The Committee was informed that the last session of the CCRVDF had noted the general results the AOAC/FAO/IUPAC/IAEA Workshop and the FAO/IAEA/AOAC Consultation[16], and the CCPR had noted the results of the FAO/IAEA/AOAC Consultation[17] but the relevant reports and guidelines had not been published at the time. The Committees had already agreed that they would take into account the relevant recommendations made in these meetings while developing criteria for the assessment of suitable analytical methods.
82) The Committee took note that the Workshop and the Consultation had made a number of recommendations concerning single-laboratory validation, including the Guidelines, and invited CCPR and CCRVDF to consider them further, in order to ensure a harmonized approach throughout Codex for single laboratory validation.
Further action
83) The Committee generally recognized that single-laboratory validation could be used for Codex purposes and agreed that the next session would consider the inclusion of a specific text in the Procedural Manual to that effect.
84) The Committee agreed that it would consider the published version of the IUPAC Harmonized Guidelines for the In-House Validation of Methods of Analysis at its next session, with a view to adopting them by reference. The Delegation of the Netherlands, with the assistance of interested countries, would revise the paper on Requirements for Single-Laboratory Validation in the light of the discussion held at the present session. In addition, the Delegation of the United Kingdom would prepare a paper on the validation of methods through the use of results from proficiency testing schemes as a separate issue.
