RECOMMENDATIONS FOR METHODS OF ANALYSIS AND SAMPLING (Agenda Item 7)

(A) Draft Revised Recommended Methods of Sampling for the Determination of Pesticide Residues for Compliance with MRLs
(B) Review of the Criteria for Selection of Methods of Analysis and In-House Validation of Methods of Analysis for Pesticide Residues

123. The Chairperson of the ad hoc Working Group on Methods of Analysis and Sampling, Dr P. van Zoonen, presented the report of the Group.

(A) Draft Revised Recommended Methods of Sampling for the Determination of Pesticide Residues for Compliance with MRLs[27]

124. The Committee recalled that it had advanced the Draft Revised Recommended Methods of Sampling[28]to Step 8 at its last Session and referred the text to the CCRVDF and CCMAS. The comments of these Committees and those from International Dairy Federation were referred to the Working Group (see para. 6). The Committee considered the Draft Revised Methods of Sampling at Step 7.

125. The Working Group considered all comments submitted to the Committee and recommended the incorporation of many of them, mostly of editorial nature. For those comments not recommended for incorporation, the reasons for non-incorporation were provided in the report of the Working Group. The Working Group also recommended the inclusion of some worked examples as an Annex to the Guidelines.

126. Based on the comments made at the Session, the Committee agreed to the following:

To accept changes suggested by the Working Group;
To add the term “for pesticides” at the end of Section 1 Objective to further clarify that the Methods of Sampling applied only to pesticide residues;
To replace the wording in Section 2.1 with the second sentence of the definition of Codex MRL contained in the Procedural Manual to highlight that, by ensuring that GAP was followed, consumer protection would be ensured;
To insert the term “should be recorded and” in Section 3.8 after the term “mixing” in the third sentence; and
To separate the schematic in Annex II into two: one for poultry and meat and another for other commodities.

127. The Committee agreed to advance the Draft Revised Recommended Methods of Sampling for the Determination of Pesticide Residues for Compliance with MRLs to Step 8 for adoption by the Commission at its 23rd Session. The agreed text is attached to this report as Appendix III.

(B) Review of the Criteria for Selection of Methods of Analysis and In-House Validation of Methods of Analysis for Pesticide Residues[29]

128. The Committee was informed by the Chairperson of the Working Group of Methods of Analysis and Sampling that the list of methods of analysis had been developed over a long period of time. Criteria to select methods exist but no such criteria exist for their deletion. Based on a number of responses to a request to identify commonly used methods in government laboratories or other laboratories involved in the determination of MRL compliance and whether these methods met the Codex and CCPR criteria[30], and on discussions within the Working Group, the Committee agreed to the following process:

i. A set of performance and validation criteria should be established to serve as a basis for judging the suitability of analytical methods for Codex purposes. These criteria would be included in Volume 2 of the Codex Alimentarius with reference to the “List of Methods in Use”.
ii. The Working Group should prepare a “List of Methods in Use” which were known to meet the established performance criteria. The detailed description of methods, together with tests demonstrating their performance, would be included in the data base recommended by the FAO/IAEA Training and Reference Centre for Food and Pesticide Control (TRC) to facilitate practical implementation of method validation. The data base would be accessible on the Home Page of the TRC and regularly updated and expanded. The “List of Methods in Use” would be reconsidered at regular intervals and the old methods automatically deleted unless evidence is received on their continued use.
iii. Until the validation criteria were established, the current list of recommended methods would not be revised or expanded.

129. The Committee was informed that the Working Group had discussed in-house validation in detail due to accreditation requirements. It noted that the Joint FAO/IAEA Expert Consultation on Validation of Analytical Methods for Food Control[31]had concluded that in-house validation was acceptable as a way of validation of methods. The Committee agreed with the proposals of the Working Group that: (1) comments should be sought through a circular letter on performance criteria of analytical methods for pesticide residue determination (Summer 1999); and (2) the Delegation of the Netherlands would collect detailed information on extraction efficiency and stability of residues in storage and in solution which were critical to in-house method validation. Based on comments provided in response to the above actions, the Netherlands would prepare a paper for consideration by this Committee at its next Session.

130. The Representative of FAI/IAEA informed the Committee of its activities including an International Workshop on Method Validation to be held in Budapest from 4 to 6 November 1999 under the auspices of FAO, IAEA, AOAC International and IUPAC. The FAO/IAEA TRC had initiated the elaboration of a Practical Approach to Validation of Multi-residue Methods with a view towards providing it to the relevant Codex Committees for consideration and subsequent adoption by the Codex Alimentarius Commission. The Representative invited participants of the CCPR to take part in the elaboration of the Practical Approach by contacting Dr Ambrus of FAO/IAEA.

131. Recognizing the need for harmonization, Committee agreed that once a new paper became available on in-house method validation, it should be sent to the CCMAS and CCRVDF to ensure consistency within Codex.

132. The Committee agreed that a working group should convene at its next Session under the chairship of Dr van Zoonen.

[27] CX/PR 99/2 and CX/PR 99/2-Add.1, CRD 5 (Report of the ad hoc Working Group on Methods of Analysis and Sampling).
[28] ALINORM 99/24, Appendix II.
[29] CX/PR 99/9, CX/PR 99/19, CRD 5.
[30] CL 1998/30-PR.
[31] Validation of Analytical Methods for Food Control, Report of a Joint FAO/IAEA Expert Consultation, Vienna, Austria 2-4 December 1997, Food and Nutrition Paper 68, FAO.