A tracer methodology has been developed and standardised for the safe and effective use of six organophosphate insecticides viz. phorate, dimethoate, methyl parathion, fenitrothion, formothion and chlorpyrifos. The proposed method is based on the adsorption of these insecticides on bentonite clay surface using carrier free 32P. The analysis has been accomplished by measuring the radioactivity at equilibrium in suspension of bentonite clay and tagged insecticide in an organic medium viz. acetonitrile.
Adsorption, bentonite, organophosphate insecticides, radioassay, formulation analysis
