霸螨灵在棉花和土壤中的残留降解动态

Degradation Dynamics of Fenpyroximate Residue in Cotton Field

于2006和2007年在济南和杭州2地进行田间试验,采用液液萃取和高效液相色谱检测方法,研究了霸螨灵在棉叶、棉籽和土壤中的残留降解动态。试验结果表明：本方法中霸螨灵的最低检出浓度为0.01 mg.kg^-1（以S/N=3计）,霸螨灵添加浓度为0.10、0.50、1.00 mg.kg^-1时,其在棉叶、棉籽和土壤中的添加回收率为72.5%-103.1%;霸螨灵在济南和杭州2地的消解趋势基本一致,在棉叶中的半衰期为3.8-4.3 d,在土壤中的半衰期为8.8-9.6 d;霸螨灵在棉籽中的最终残留量均〈0.01 mg.kg^-1,在土壤中的最终残留量〈0.01-0.98 mg.kg^-1。建议我国将霸螨灵在棉籽中的MRL（最高残留限量）值定为0.1 mg.kg^-1。

Field experiments were carried out in Jinan and Hangzhou and laboratory analysis performed to determine dynamics of fenpyroximate residue in cotton leaves, cotton seeds and soil, using liquid extraction method and HPLC method. Results show that the lowest detectable limit of the method was 0.01mg.kg^-1 （ S/N= 3 ）. When the pesticide was applied at a rate of 0.10,0. 50,1. 00 mg.kg^-1 ,its recovery rate varied in the range of 72.5% -103.1%. Degradation of fenpy- roximate in cotton fields in Jinan and Hangzhou demonstrated a similar trend. The half-life of fenpyroximate in cotton leaves was in the range from 3.8 to 4.3 days,and in soil from 8.8 to 9.6 days. The final residue of fenpyroximate was 〈0.01 mg.kg^-1 in cotton seeds,and 〈0.01 to 0.98mg.kg^-1 in soil. It is,therefore, suggested that the MRL （ maximum residue level） of fenpyroximate in cotton seeds be set at 0.1mg.kg^-1.