Multi-residue Determination of Synthetic Pyrethroids and Organophosphorus Pesticides in Whole Wheat Flour using Gas Chromatography

摘要

Wheat grain in the form of flour and its processed products have become and essential part of human diet. The consumption of wheat flour and its products is increasing everyday throughout the world. As a result of increasing demand in Pakistan, cultivation and production of wheat crop has increased tremendously. However, the system still in primitive and is facing many pre and post harvest problems that requiring to be addressed. There are two principal sources of pesticides contamination in stored commodities, pesticide residues resulting from field spraying and the residues accumulated as a result of pesticides' admixture with grain or fabric treatment during storage. Cereal grain are treated with degradable pesticides, including organophosphates,carbamates, synthetic py-rethroids and insect growth regulators in storage premises as well as prior to shipment to other countries to prevent insect infestation. In this regard, residual efficacy of some pesticides in stored wheat studied by Arthur (1992). Noble et al. (1982) studied the stability of pyrethroids. A large number of pesticides are in common use as grain protec-tants. This usage has been comprehensively reviewed by Snelson (1987). The identification and quantification of pesticide residues in flour as well as in its products is important because small quantity of pesticides or their metabolites may persist in flour after processing or refining even in baked or cooked products (Skerritt et al. 1996). Therefore it is necessary to monitorflour for pesticides residues.