LC/TQ mass spectrometry analysis for estimation of residual behavior and dissipation kinetics of isocycloseram and its metabolite's in/on tomato (Solanum lycopersicum)

Isocycloseram is a new isoxazoline group pesticide with novel mode of action and very effective against various insect and mite species. The study was undertaken to determine the residual behavior of isocycloseram in/on tomato fruit and soil using liquid chromatography-tandem mass spectrometry. The limit of quantification and limit of detection were workout to be 0.01 and 0.003 μg/g, respectively for isocycloseram and the metabolites. The recovery of isocycloseram and metabolites were 94–105 % in tomato matrix and in soil matrix recovery was 93–101 % with < 20 % relative standard deviation. After applications of 60 and 75 g a.i./ha, the total initial residues of isocycloseram (including metabolites) on tomato fruits were 0.411 and 0.670 µg/g that dissipated to half in 3.13 and 3.46 days at respective doses. The hazard quotient computed for the insecticide was below one thus indicating its safety for humans. •This is the first study to determine dissipation of isocycloseram on tomato.•The method showed satisfactory recovery and high sensitivity.•A pre-harvest period of 4 days recommended for tomato consumption.•Consumption of tomato fruit was toxicologically safe at detected concentrations.