Residue Degradation of Fluopyram and its Metabolites during Tobacco Planting and Processing

To investigate the residue degradation of fluopyram and its metabolite AE C656948-Benzamide during tobacco planting and processing, the QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (QuEChERS-UPLC-MS/MS) method was adopted to detect the residues of fluopyram and its metabolite in tobacco leaves. At addition levels of 0.05-10 mg/kg, the results showed that the average recoveries of fluopyram in fresh leaves and cured leaves were 86%-94% and 81%-95%, AE C656948-Benzamide were 85%-91% and 83%-89%, with relative standard deviations (RSD) less than 10%. The quantitative limits for fluopyram and AE C656948-Benzamide in fresh leaves and cured leaves were both 0.05 mg/kg. The degradation rate of fluopyram was more than 50% in the first 3 days, but it was slow after then. During curing the degradation rate of fluopyram residue was 58.1% and the degradation rate of AE C656948-Benzamide residue was 52.9%. The processing factors (Pf) were in the range of 0.42-0.47. The degradation rate of fluopyram was 1.8% and AE C656948-benzamide was not degraded within 360 days during aging. The Pf varied in the range of 0.99-1.54. In conclusion, fluopyram and AE C656948 benzamide degrade significantly during tobacco planting and baking, but rarely during aging.