Residue behaviour of profenofos and triazophos in okra (Abelmoschus esculentus) and their decontamination using culinary processes

Abstract

The persistence pattern and risk assessment of profenofos and triazophos in okra (Abelmoschus esculentus (L.) Moench) and cropped soil were studied in the present study. The insecticides were applied twice at 10 days interval @ 500 and 1000 g a.i./ha. Residues were quantified at 0, 1, 3, 5, 7, 10, 15 and 20 days of second application using GC equipped with Flame Photometric Detector (FPD). The average initial deposits of triazophos (1.838 mg/kg) in okra fruits were higher than profenofos (1.418 mg/kg) at the recommended application rates. Both the insecticides followed a first order kinetics with half-lives of 1.6 and 1.4 days, respectively on okra fruits. The initial deposits of 0.483 and 0.500 mg/kg, for respective insecticides, disappeared to BDL on 5th and 7th day in okra cropped soil. Microwave oven cooking proved more promising than other household processing in dislodging the residues of test insecticides from okra fruits. On the basis of this study, waiting periods of 7.6 and 7.4 days were suggested for consumption of okra sprayed with profenofos and triazophos, respectively.