Dissipation and residue of fenpropidin in wheat and soil under field conditions.

The residue levels and dissipation rate of fenpropidin in wheat and soil were investigated by LC-MS/MS and GC-MS, respectively. The dissipation rates of fenpropidin were described using first-order kinetics and its half-life ranged from 3.1 to 3.3 days in wheat plants and 13.4-16.5 days in soils. During harvest time, the terminal residues of fenpropidin in wheat were below the EUs maximum residue limit (MRL, 0.5 mg kg(-1)) when collected 20 days after the final application, which suggested that the use of this fungicide was safe for humans. The residues persistence varied between two geographically separated experimental sites, indicating that it might be influenced by climate, soil properties and growth dilution factor. These results would be helpful in setting MRL guidance of fenpropidin in wheat in China.