Persistence of Indoxacarb on Cauliflower (Brassica oleracea var. botrytis. L.) and Its Risk Assessment

A rapid, simple and an efficient method for the determination of indoxacarb in cauliflower and soil samples was developed and validated using QuEChERS technique (Quick, Easy, Cheap, Effective, Rugged and Safe). Recoveries at four different spiking concentrations of 0.01, 0.05, 0.1 and 0.2 mg·kg ranged from 87% to 96% were achieved with good repeatability and RSD of 1% 6%. The average initial deposits of 0.23 and 0.45 mg·kg were observed after last application of indoxacarb @ 52.2 and 104.4 g. a.i. ha at recommended and double the recommended dosages, respectively. The residues in cauliflower dissipated below its LOQ of 0.01 mg·kg after 7 days and its half-life periods were observed to be 1.12 and 1.31 days, respectively, at single and double the dosages. Keeping in view 80 g consumption of cauliflower curds per day for a 55 kg person, theoretical maximum residue contribution (TMRC) of indoxacarb when calculated from maximum residues observed on 0 day samples at recommended and double the recommended dosages, respectively, were found to be 20.8 and 36.8 μg in comparison to its acceptable daily intake (ADI) of 550 μg, which is quite safe.