Collaborative testing, pesticide

Miscellaneous pesticides/insecticides Spinach Collaborative testing of methodology [130]... 

Recently there has been progress towards a universal acceptance of collaboratively tested methods and collaborative trial results and methods, no matter by whom these trials are organised. This has been aided by the publication of the IUPAC/ISO/AOAC Harmonisation Protocol on Collaborative Studies.14 That Protocol was developed under the auspices of the International Union of Pure and Applied Chemists (IUPAC) aided by representatives from the major organisations interested in conducting collaborative studies. In particular, from the food sector, the AO AC International, the International Organisation for Standardisation (ISO), the International Dairy Federation (IDF), the Collaborative International Analytical Council for Pesticides (CIPAC), the Nordic Analytical Committee (NMKL), the Codex Committee on Methods of... 

The Committee expressed concern at the fact that different chemical and physicochemical test methods are recommended by WHO and FAO. The FAO specifications give references to official and collaboratively tested methods adopted by the Collaborative International Pesticide Analytical Council (CIPAC) or by AO AC International (AOAC) and published by these organizations but do not provide full texts of the methods. In WHO specifications published up to 1997, the chemical and physicochemical methods are described in full, with the specifications, or under the heading WHO test methods in the same document. In some new Interim Specifications... 

Collaborative testing procedures should be developed for plant-based pesticides. In this context it was noted that FAO is already processing a request for a specification for a plant-based pesticide. 

The development of specifications cannot be effectively accomplished without proper analytical methodology. This also includes physical tests to ensure suitability as well as chemical analyses. Recognition of this need has led to international cooperation and coordination of effort. In this respect the Collaborative International Pesticides Analytical... 

Brown (1970) mentioned the blue test and commented that it can be considered a useful indicator of the biological activity of PBO, since the allied cam-pounds, believed to have synergistic properties, contribute to the colorimetric response of the commercial product- In 1971, the Collaborative International Pesticides Analytical Council (CIPACJ also adopted the colorimetric test as its official method for PBO analysis. 

Calibration data (e.g., linearity or sensitivity) are not discussed in detail between laboratories, but a typical calibration starts with 50% of the lowest fortification level and requires at least three additional calibration levels. Another point of calibration is the use of appropriate standards. In 1999 a collaborative study tested the effect of matrix residues in final extracts on the GC response of several pesticides.Five sample extracts (prepared for all participants in one laboratory using the German multi-residue procedure) and pure ethyl acetate were fortified with several pesticides. The GC response of all pesticides in all extracts was determined and compared with the response in the pure solvent. In total, 20 laboratories using 47 GC instruments... 

We consider all these field tests still to be preliminary. They will have to be repeated on a larger scale and in different locations and countries before a complete picture can be gained. The work on Spodoptera exigua in Holland was done in collaboration with W.J. Nooijen of the Delft group and C. van der Kraan and S. Voermanof the Institute for Pesticide Research in Wageningen. 

These activities have enabled WHOPES to plan for the expansion of the Scheme to include the testing and evaluation of a greater variety of pesticides. In recent years, WHOPES has also vigorously promoted the use of WHO specifications for public health pesticides in accordance with the International Code of Conduct on Distribution and Use of Pesticides. Examples of such efforts include the development and wide distribution of guidelines for the purchase of pesticides for public health use, provision of access to WHO specifications for pesticides and their test methods on the Internet, and an increase in the number of WHO collaborating centres for quality control of pesticides (currently three). 

Reference 9 describes a collaborate survey of over 28 laboratories testing the new Tentative Standard Method for Chlorinated Hydrocarbon Pesticides in distilled water. This method calls for two successive extractions utilizing a hexane, semi-automatic extraction as described by Kawa-hara et al, 10) and modified by Schaefer et al, (11) Three different chlorinated hydrocarbon pesticide mixtures were tested only three of eighteen pesticides analyzed showed a total error of less than 50%. This calculation of the total error was based upon Table 100 (3) which described the accuracy and precision of the new method (9). 

Current work Is aimed at developing prototype antibody kits for use by the grain Industry. Considerable stability testing and collaborative trialling Is, however, required before this can be done. Assay validation of pesticide ELISAs has also been reviewed elsewhere(20. While quantitative ELISA kits... 

An estimated 450 scientific experts at the Army Gas Protection Laboratory Heeresgasschutzlaboratorium) in Berlin-Spandau, officially tasked with chemical defence, synthesized thousands of chemical compounds to see whether any of them could be developed into warfare agents, performed tests on animals and humans, established collaborative networks and secret contracts with private companies, including IG Farben, conducted extensive htera-mre reviews, and secured the support of the State Patent Office, yet up until the mid 1930s no major advances had been made. In the end, the discovery of the first major new warfare agent since the First World War was largely unrelated to the allocation of government resources or to the provision of military expertise it resulted from research into new synthetic pesticides. 

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