土壤和番茄中氯虫苯甲酰胺的残留检测与消解动态研究

研究和建立了氯虫苯甲酰胺在土壤和番茄中的液相色谱检测方法,并采用田间试验方法研究了氯虫苯甲酰胺在土壤和番茄中的残留消解动态规律。结果表明,采用甲醇溶液浸泡提取,减压浓缩后用二氯甲烷萃取,浓缩后用二氯甲烷定容,液相色谱仪带二极管阵列检测器（DAD）测定,外标法定量。在0.05～0.5mg·kg-1添加水平范围内,土壤和番茄中氯虫苯甲酰胺的添加平均回收率为91.43%～100.91%,变异系数为3.53%～9.71%;土壤和番茄中氯虫苯甲酰胺的最小检出量均为1.0×10-7g,最低检出质量分数为0.005mg·kg-1。田间残留试验表明,氯虫苯甲酰胺在土壤和番茄中残留消解动态规律符合方程Ct=C0e-kt;150g·L-1高效氯氟氰菊酯·氯虫苯甲酰胺微囊悬浮-悬浮剂在土壤和番茄中的消解半衰期分别为6.55～11.49d和3.82～10.70d。最终残留试验研究表明,在番茄上手动喷雾施药150g·L-1高效氯氟氰菊酯·氯虫苯甲酰胺微囊悬浮-悬浮剂,按推荐剂量和1.5倍推荐剂量施药,兑水喷雾处理2～3次,施药间隔为7d,最后一次施药距采收间隔7d时,氯虫苯甲酰胺在番茄中最高残留量均小于0.3mg·kg-1。参照欧盟等规定的氯虫苯甲酰胺在番茄中最大残留限量标准,按照推荐剂量和1.5倍推荐剂量施药2～3次,距最后一次施药7d时,氯虫苯甲酰胺在番茄上残留是安全的。

Residue Determination and Degradation of Chlorantraniliprole in Soil and Tomato

An analytical method of liquid chromatography（HPLC）was established for determining chlorantraniliprole residue in soil and tomato,and the residue and degradation of chlorantraniliprole in tomato and soil were investigated.Chlorantraniliprole residue was extracted by methanol,then extracted by dichloromethane,and determined by HPLC equipped with a DAD detector.The experimental results showed that the average recoveries of chlorantraniliprole stood with a range of 91.43%～100.91% at three spiking levels from 0.1 mg·kg-1 to 1.0 mg· kg-1 with their relative standard deviations of 3.53%～9.71% in tomato and soil.Limit of detection was 1.0×10-7 g and the lowest concentrations detected were 0.005 mg·kg-1 in soil and tomato.An control and contrast trial experiments in Tianjin municipal,Shandong Province and Zhejiang Province were done.The degradation of chlorantraniliprole in tomato and soil could be described with equation：Ct=C0e-kt.The halflife of chlorantraniliprole turned to be 6.55～11.49 d in soil 3.82～10.70 d in tomato,respectively.The pesticide of chlorantraniliprole was applied as foliage spray according to the recommended dosage and the 1.5 times recommended dosage for twice and three times at an interval of 7 d.The final residue of chlorantraniliprole was low than 0.3 mg·kg-1 in tomato.According to the results,we recommend that 150 g·L-1 lambda-cyhalothrin chlorantraniliprole WP were applied as foliage spray for twice and three times at 1.5 times recommended dosage for tomato with a safe interval of 7 days from harvest.