秋葵中甲氨基阿维菌素苯甲酸盐残留及消解动态

Residue and degradation dynamics of emamectin benzoate in okra

中文关键词:  甲氨基阿维菌素苯甲酸盐  秋葵  残留消解  安全间隔期  

英文关键词:emamectin benzoate  okra  residues digestion  safety interval

中文摘要:

      目的 建立高效液相色谱-串联质谱法测定秋葵中甲氨基阿维菌素苯甲酸盐残留量的分析方法, 并研究其在秋葵中的消解动态规律和最终残留。方法 样品采用乙腈进行提取, N-丙基乙二胺(n-propyl ethylenediamine, PSA)净化, 以0.05%甲酸水-甲醇作为流动相梯度洗脱分离, 在选择反应检测扫描(selective reaction monitoring, SRM)模式下扫描定性, 标准曲线外标法定量, 分析了河北、贵州的消解动态和最终残留样品。结果 在浓度为0.001~1.00 mg/kg的添加水平下, 秋葵中的甲氨基阿维菌素苯甲酸盐的回收率为104.7%~107.5%, 变异系数为0.73%~1.26%, 检出限(limit of detection, LOD)为1.0×10?12 g, 定量限(limit of quantification, LOQ)为0.001 mg/kg。2018年在河北、贵州两地进行的消解动态试验表明, 甲氨基阿维菌素苯甲酸盐在秋葵上的半衰期分别为13.3、8.3 d, 最终残留试验结果显示不同收获期秋葵中甲氨基阿维菌素苯甲酸盐最高残留量为0.010 mg/kg。结论 甲氨基阿维菌素苯甲酸盐用于防治秋葵中斜纹夜蛾等害虫, 推荐使用3.4%甲维盐微乳剂, 施药剂量3.0 g a.i./hm2, 最多施药2次, 安全间隔期3 d, 收获期的秋葵食用安全。

英文摘要:

      Objective To establish a method for the determination of emamectin benzoate in okra by high performance liquid chromatography-tandem mass spectrometry, and study the degradation dynamics and final residue of emamectin benzoate in okra. Methods The samples were extracted with acetonitrile, purified by n-propyl ethylenediamine, using 0.05% formic acid water-methanol as the mobile phase for gradient elution separation, the samples were identified by scanning in selective reaction monitoring (selective reaction monitoring, SRM) mode and quantified by standard curve external standard method. The degradation dynamics and final residual field samples in Hebei and Guizhou were analyzed. Results At the added level of 0.001?1.00 mg/kg, the recoveries of emamectin benzoate in okra were 104.7%?107.5%, the coefficient of variation was 0.73%?1.26%, the limit of detection (LOD) of emamectin benzoate was 1.0×10?12 g and the limit of quantification (LOQ) was 0.001 mg/kg. The digestion dynamic tests in Hebei and Guizhou in 2018 showed that the half-life of emamectin benzoate in okra were 13.3 days and 8.3 days. In the final residual test, the largest residues of emamectin benzoate in okra in different harvest periods was 0.010 mg/kg. Conclusion Emamectin benzoate is used to control Spodoptera litura and other pests in okra. It is recommended to use 3.4% emamectin benzoate microemulsion with an application dosage of 3.0 g ai/hm2. with a maximum application time of 2 times and a safe interval of 3 days. The okra is safe to eat in harvest .