Residue and risk assessment of pyridaben in cabbage.

The dissipation and residue of pyridaben in cabbage under field conditions were investigated. A sensitive, simple, and fast method for determining pyridaben in cabbage was established by high-performance liquid chromatography tandem mass spectrometry. The average recoveries were in the range of 90.29-95.00% with relative standard deviations ranging from 1.72% to 6.39%. The field results showed that pyridaben dissipated rapidly in cabbage and had a half-life of 2.8-3.5 d. During harvest, the terminal residues of pyridaben were 0.01-0.80 mg/kg. Given that no maximum residue limit (MRL) has been set for pyridaben in cabbage, risk assessment was evaluated by using the risk quotient (RQ). Results indicated that the RQ value was significantly lower than RQ = 1. Thus, the effect of pyridaben in cabbage at the recommended dosage was negligible to humans. This study could provide guidance for the safe and reasonable use of pyridaben as a broad-spectrum acaricide and serve as a reference for the establishment of an MRL in China.