氯虫苯甲酰胺和高效氯氟氰菊酯在豇豆和土壤中的残留行为

建立了采用分散固相萃取法进行样品前处理，分别用液相色谱-质谱联用和气相色谱检测14%氯虫苯甲酰胺·高效氯氟氰菊酯微囊悬浮剂中2种有效成分在豇豆和土壤中的残留量及消解动态的方法。结果表明:豇豆和土壤中分别添加0.005～1 mg/kg 4个水平的氯虫苯甲酰胺和高效氯氟氰菊酯，其平均回收率为80%～105%，相对标准偏差为0.70%～9.5%。北京和海南2地氯虫苯甲酰胺和高效氯氟氰菊酯在豇豆中的半衰期为4～6 d，土壤中的为10～24 d。成熟时采收，豇豆中氯虫苯甲酰胺和高效氯氟氰菊酯的残留量均低于0.2 mg/kg。推荐14%氯虫苯甲酰胺·高效氯氟氰菊酯微囊悬浮剂在豇豆上的使用剂量为有效成分45 g/hm2，使用方式为喷雾，施药次数不超过3次，施药间隔期为7 d，安全间隔期为5 d。

Residual behavior of chlorantraniliprole and lambda-cyhalothrin in cowpea and soil

The residue and dissipation dynamic of chlorantraniliprole and lambda-cyhalothrin in cowpea and soil were investigated. A dispersive solid phase extraction method was established for the pretreatment, while LC-MS/MS and GC-ECD chromatography were employed for the analysis. The result has shown that the recovery rate ranges from 80% to 105% and the variation coefficient ranges from 0.70% to 9.5%, when chlorantraniliprole and lambda-cyhalothrin are added to the cowpea and soil at the concentration ranging from 0.005 to 1 mg/kg (four concentrations). The half-lives of chlorantraniliprole and lambda-cyhalothrin in cowpea at Beijing and Hainan are 4-6 days; The half-lives of chlorantraniliprole and lambda-cyhalothrin in soil in the above mentioned two regions are 10-24 days. The residues in stems of cowpea were lower than 0.2 mg/kg at the harvest time. We recommend Good Agricultural Practices of chlorantraniliprole and lambda-cyhalothrin 14% aqueous capsule suspension (CS) used in cowpea are as follows:maximum using dose is 45 g a. i/hm², spray at growth phase and no more than 3 times, applying pesticide interval is 7 days, and preharveat interval is 5 days.