METHODS OF SAMPLING AND ANALYSIS FOR PESTICIDE RESIDUES[19] (Agenda item 10)

(a) REVISION OF RECOMMENDED METHODS OF SAMPLING FOR THE DETERMINATION OF PESTICIDE RESIDUES
(b) LIST OF RECOMMENDED METHODS OF ANALYSIS
(c) MRLS SET AT OR ABOUT THE LIMIT OF DETERMINATION

(a) REVISION OF RECOMMENDED METHODS OF SAMPLING FOR THE DETERMINATION OF PESTICIDE RESIDUES[20]

88. The Committee noted the general principles contained in the document and the newly added sections on preparation of the analytical sample and on preparation and storage of the analytical portion. However, it pointed out that some of the currently recommended methods, such as those for eggs, processed cheese, herbs and spices, and poultry offal, were inappropriate and that the document needed some textual changes. The Committee decided to return the revised methods of sampling to Step 3 for redrafting[21] and circulation for government comments well before the next session. It was noted that the sampling of costly products, such as saffron, should be given special consideration.

(b) LIST OF RECOMMENDED METHODS OF ANALYSIS

89. The Committee was informed by the Chairman of the ad hoc Working Group, Dr. van Zoonen (The Netherlands) that a revised list for methods of analysis had been elaborated for the 194 compounds presently listed in the Codex system. For seven compounds (cycloxidim (179), ethofenprox (184), clethodim (187), teflubenzuron (190), fenarimol (192), fenproximate (193) and haloxyfop (194)) not even a tentative method could be listed due to lack of information on these compounds in open literature. A revised version of the list would be circulated for comments. There was discussion on the status of the methods cited and the criteria for inclusion in the list. Government comments were requested on the criteria and whether the methods could be considered as “recommended” by Codex.

(c) MRLS SET AT OR ABOUT THE LIMIT OF DETERMINATION

90. The Committee once again endorsed the definition of limit of determination (LOD)[22] as well as the concept that MRLs set at or about the LOD should be set at levels that can be achieved routinely with an acceptable level of confidence, in any normally equipped regulatory laboratory. The following MRLs were evaluated using the above statements[23]:

- Methidathion (051): no changes were proposed;

- Disulfoton (074): MRLs indicated with (*) were amended from 0.01 to 0.02 mg/kg; and

- Abamectin (177), no consensus could be reached, and comments were requested to assess whether an LOD of 0.01 mg/kg was realistic.