Residue and dissipation kinetics of novel nematicide fluopyram in rice assessed by QuEChERS-liquid chromatography-tandem mass spectrometry.

Abstract

Supervised field trial was conducted to study the dissipation pattern of fluopyram in rice plant after application of fluopyram 400g/L SC(Velum Prime) as soil drenching at the time of sowing in nursery bed at X (500g a.i. ha-1) and 1.25X (625.2g a.i. ha-1) doses. Samples of rice plant were collected on 0, 1, 3, 7, 10, 15, and 20days after transplanting. QuEChERS-based extraction method was validated and adopted to determine the residues of fluopyram in rice seedlings, whole rice grains (with husk), polished rice grain, husk, straw, and soil using LC-MS/MS (liquid chromatography-tandem mass spectrometry).The initial deposit of fluopyram in rice plant recorded were 0.27 and 0.41mgkg-1in X and 1.25X doses, respectively. Fluopyram residues dissipated following first-order kinetics with half-life of 2.53 and 2.57days at X and 1.25X doses, respectively. Residues were detected in seedlings up to 15days after transplanting and were at below LOQ in whole rice grains (with husk), polished rice grain, husk, straw, and soil collected at harvest. Monitoring study revealed that application of novel nematicide fluopyram for the management of nematodes in rice does not pose any risks to consumers.