Study On Residue And Degradation Dynamics Of Difenoconazole In Litchi And Soil

A fast and reasonable analysis method for determination of difenoconazole in litchi and soil by GC was established. The limit of detection was 2.0×10-11g, and the limit of quantification was 0.02 mg/kg in litchi, litchi pulp and soil. When concentration of difenoeonazole ranges from 0.02 mg/kg to 2.0 mg/kg, the average recovery was 87.35%-93.38% in litchi,84.80%-90.84% in litchi pulp and 85.90%-92.91% in soil sample. The dissipation dynamics of difenoconazole 10% water dispersible granule in litchi and soil was studied and analyzed in this article. Results showed that the dissipation dynamics of fungicides was accorded with first order reaction kinetics equation in litchi and soil. The half-life of difenoeonazole in litchi and soil was 10.78 d and 11.71 d in Haikou city. In Nanning city, the half-life of difenoeonazole in litchi was 8.61 d, the half-life of difenoeonazole in soil was 13.54 d. The final residue experiment of difenoeonazole in litchi and soil indicated that the recommended concentration used in asparagus was safe. The correlation between residue of difenoeonazole and the applying concentration and degree was markedly positive.