毒死蜱在叶菜上的残留及降解动态分析

Analysis on residual dynamics of chlorpyrifos and its degradation in leafy vegetables

以芥菜为例,对露地条件下生产的叶菜类蔬菜中毒死蜱的残留及降解规律进行研究。结果表明,毒死蜱在芥菜中的降解速率在喷药后5 d内呈直线下降趋势,第5 d后降解趋于平稳;毒死蜱在芥菜中的残留量随着喷施浓度的增加而增加;以毒死蜱最高推荐浓度和低于最高推荐浓度3倍的药液量进行喷洒,在7 d安全间隔期及安全间隔期满2d后,毒死蜱在芥菜中的残留量均高于国家标准。因此,建议对毒死蜱的推荐使用浓度、施用次数、安全间隔期等做进一步的试验研究,以确保蔬菜的食用安全。

The present experiment has been conducted to find out the dynamics of chlorpyrifos residue and its degra- dation by planting mustard （leafy vegetable） in exposed soil. The results indicated that the chlorpyrifos residue in mustard leaf decreased linearly after five days of spray, and tended to be steady after that. The residues increased with the increase in chlorpyrifos concentration sprayed on mustard leaf. After spraying 500× and 1500× diluted ehlorpyrifos, the final chlorpyrifos residues, assayed during 7 d safe interval period and 2 d later, were higher than the national standard （0.1 mg/kg）. Therefore, for food safety purposes, further studies should be taken to work out recommended concentration, spray times and safe interval period for chlorpyrifos application.