Dissipation dynamics and residue analysis of pydiflumetofen and difenoconazole in tobacco
[Aims]This study aims to determine the dissipation dynamics and residues of pydiflumetofen· difenoconazole 200 g/L suspension concentrate on tobacco.[Methods]Based on field trial data,a high performance liquid chromatography tandem mass spectrometry method was established for the simultaneous determination of pydiflumetofen and difenoconazole on tobacco.[Results]After applying pydiflumetofen·difenoconazole 200 g/L suspension concentrate twice,the original residual amount of pydiflumetofen for fresh tobacco leaves and dried tobacco leaves was 2.2 and 6.2 mg/kg,respectively;the dissipation rate was 51.7％-70％on day 14 after application,and the half-life was 6-9 d.The original residual amount of difenoconazole for fresh tobacco leaves and dry tobacco leaves was 3.1 and 14 mg/kg,respectively;the dissipation rate was 58.1％-83.6％on day 14 after application,and the half-life was 4-9 d.Dissipation of pydiflumetofen and difenoconazole in tobacco was in accordance with the first-order kinetics equation,therefor it was easy to degrade.On day 14 after application of pydiflumetofen·difenoconazole 200 g/L suspension concentrate,the maximum residue was 0.52 and 0.55 mg/kg in fresh tobacco leaves,1.68 and 2.24 mg/kg in dry tobacco leaves,respectively.[Conclusions]The results of this study provide data support for the safe use of pydiflumetofen and difenoconazole on tobacco and the establishment of maximum residue limits in China.
NETL
NSTL
万方数据
维普
