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Volume :31 Issue : 1 2004
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Performance in interlaboratory analytical quality assurance studies on pesticide residues in spiked food samples
Auther : ALI S. AL-OMAIR*, NISAR AHMED,
Central Analytical Laboratory, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat, 13109, Kuwait. Tel: 00965-4813293 Fax: 00965-4815197 Email:aomair@kisr.edu.kw
ABSTRACT
Analysis of pesticide residues in a large number of foods related to total diet study required stringent quality controls. In addition to routine quality controls, our lab participated in two interlaboratory analytical quality assurance studies on pesticides residues in spiked samples of rice flour and orange powder. Analyses were made by gas chromatography with electron capture detector, Hall detector and flame photometric detectors for the selected chlorinated and phosphorylated compounds. Sample preparation, extraction, clean up, fractionation and analysis were carried out according to the procedure described in the US-Food & Drug Administration’s, ‘Pesticides Analytical Manual’, with a few modifications suitable to our analytical facilities. The results show that our values were close to the overall total mean values obtained by 50-70 participating laboratories. The performance of our laboratory was found satisfactory on the basis of Z-score values which were less than ±2 for most of pesticides analyzed in the two spiked samples.
Keywords: Food; interlaboratory; pesticides; quality controls; residues