Spectrophotometric and Thin Layer Chromatographic Methods for Determination of Residues of Fenvalerate, Cypermethrin and Deltamethrin in Cereals

Spectrophotometric and thin layer chromatographic methods for the determination of residues of fenvalerate, cypermethrin and deltamethrin in cereals have been developed. The method is based on the reaction of synthetic pyrethroids with sodium hydroxide with the liberation of cyanide ion. The cyanide is converted into cyanogen bromide which forms colour with benzidine-pyridine chromogenic reagent. The method has been successfully applied for the analysis of synthetic pyrethroids in cereals. Recoveries of synthetic pyrethroids in wheat and rice grains are in the range of 80 to 95%.