Dissipation and residues of picoxystrobin in peanut and field soil by QuEChERS and HPLC-MS/MS.

The dissipation and final residues of picoxystrobin in peanut and soil were determined by a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The dissipation and final residue of picoxystrobin at three different provinces (Hebei, Hubei, and Shandong) in China were studied. The fortification experiments at three different spiking levels of 0.01, 0.05, and 0.5 mg kg(-1) in all matrices (soil, peanut seedling, shell, stalk, and kernels) were conducted, and the recoveries were 79-114% with relative standard deviations of 3-12 (n = 5). The dissipation half-lives of picoxystrobin were 1.5-8.6 days in soil, and 2.1-2.8 days in seedlings. The final residues of picoxystrobin in supervised field trials were 0.05-6.82 mg kg(-1) in stalk, ≤0.381 mg kg(-1) in soil, ≤0.069 mg kg(-1) in shells, and ≤0.005 mg kg(-1) in peanut kernels. Considering the final residue levels and the maximum residue limits (MRLs), the pre-harvest interval of 14 days was recommended for the safe use of picoxystrobin in peanut crop.