Residual persistence of chlorpyrifos, imidacloprid and acephate in brinjal fruit

Residual persistence of chlorpyriphos , imidachloprid and acephate was investigated by adopting HPTLC with acetylcholine esterase inhibition method. These insecticides were sprayed on the brinjal crop during May, 2004 and residues on brinjal fruit were assessed 3 hours, 3 days and 7 days after application. The residues of the aforesaid insecticides on the three sampling periods (max-min) ranged from 0.075-0.039, 0.030-0.015 and 0.067-0.040 ppm, respectively. The quantity of insecticide residues was negligible in the brinjal fruit. This leads to conclusion that it is safe to recommend brinjal fruit for human consumption after three days of spraying the above said insecticides.