Persistence and effects of processing on reduction of chlorantraniliprole residues on cowpea fruits.

A field trial was conducted to study the dissipation kinetics of chlorantraniliprole 18.5 % SC on cowpea fruits. The fruit samples drawn periodically were analyzed by liquid chromatography and tandem mass detection (LC-MS/MS). The initial residues of chlorantraniliprole in cowpea fruits were found to be 0.55 mg kg(-1) which dissipated rapidly, with a half-life of 1.31 days and a waiting period of 0.62 days following first order kinetics. Processing of the fruits with solutions commonly used in households reduced the insecticide residues on cowpea fruits harvested 2 h after spraying by 47.19 %-91.70 % and 44.56 %-91.25 % on fruits plucked on the third day.