Method validation, residue dissipation and dietary risk assessment of tetraniliprole, BCS-CQ63359, spirotetramat and its metabolites in or on tomato using LC-MS/MS.

A method for estimation of residues of spirotetramat, tetraniliprole and their metabolites in tomato was validated using QuEChERs extraction with acetonitrile followed by estimation with liquid chromatography-tandem mass spectrometry with coefficient of determination (R²) ≥ 0.99. The untreated samples of tomato and soil fortified with tetraniliprole, spirotetramat and their metabolites at three levels of 0.01, 0.05 and 0.1 µg g^-1, gave a recovery in the range of 72-91% with relative standard deviation, RSD ≤ 8.0%. Combination product (Tetraniliprole 120 g L^-1 + Spirotetramat 240 g L^-1 SC) was applied thrice at 375 and 469 g a. i. ha^-1 dosages at 7 d interval in tomato, from fruit setting stage. Half-life of total tetraniliprole at lower and higher doses was 5.65 and 7.46 d, while that for spirotetramat in tomato were 2.16 and 2.17 d. The waiting periods calculated were 4.72 and 11.97 d for total tetraniliprole and 1.11 and 1.24 d for spirotetramat in tomato. The risk assessment of the residues revealed that the combination product applied at lower and higher doses in tomato did not pose any risk to humans, even when consumed on the same day of application and hence can be safely recommended for management of pest complex in tomato under Indian conditions.