Persistence and dissipation of neonicotinoid insecticides on chilli fruits

A field trial was conducted to study the dissipation of neonicotinoid insecticides, imidacloprid and acetamiprid, on chilli fruits for the estimation of its half-life and waiting period. The samples of chilli fruits drawn at 0, 1, 3, 5, 7, 15, 21 days after spraying were quantified on gas liquid chromatography equipped with Ni-63 electron capture detector for acetamiprid and high performance liquid chromatography for imidacloprid. The residues of imidacloprid persisted up to seven days, whereas the acetamiprid persisted up to fifteen days of spraying. From the dissipation data, the half-life values of acetamiprid and imidacloprid were 2.27 and 2.08 days, respectively. A waiting period of 7.18 and 11.26 days were calculated for acetamiprid and imidacloprid in chilli.