Abstract:

Field trial and gas chromatography are carried out to study residual decline of myclobutanil in the litchi and soil in order to illustrate the declines and environmental assessment of myclobutanil. The pesticide was extracted using methanol from samples, cleaned by the column of florisil and determined by capillary column gas chromatography with ECD. The results in Guangdong and Guangxi showed that the decline of myclobutanil in litchi and soil followed the first-kinetic equation, and the half-lives were 2.2-2.5 days in litchi and 2.8-3.1 days in soil, respectively. The litchi was sprayed three times with 40% myclobutanil WP according to the recommended dosage 100 mg a.i./kg, the results revealed that the myclobutanil residues in litchi were all below the 2 mg/kg. It was recommended that the MRL of myclobutanil in litchi set at 2 mg/kg.