Residue and Degradation Behavior of Difenoconazole in Cucumber and Its Soil

In order to research the ecological environment safety of difenoconazole after using in cucumber field,and guide the scientific and rational use of difenoconazole and its preparations,the remnant allowance examination method of the difenoconazole in cucumber and soil was studied and established by adding recovery experiment with GC technique,and the residue and degradation dynamics of difenoconazole in cucumber and soil was studied after 10% difenoconazole WG was used in cucumber field by this method.The results showed that: ①The residue of difenoconazole in cucumber and soil could be extracted by acetone,extracted with dichloromethane,and then purified by a florisil column,finally detected with GC-ECD.And the limit of detection with this method was 1.0×10-11g.The lowest detectable concentrations in cucumber and soil were 0.05 mg/kg.②When the added concentration ranged from 0.05 to 1.00 mg/kg,the recoveries changed from 89.22% to 99.80%,with the variation coefficients between 1.04% and 5.41%.The result suggested that the residue determination method of difenoconazole could meet the requirement of pesticide residues technical specifications.③After use of 10% difenoconazole WG in cucumber field,the degradation half life of difenoconazole in cucumber and soil was 6.46~9.94 d.It showed that difenoconazole degraded easily in cucumber field.