毒死蜱在大白菜上的消解动态研究

Research on Degradation Dynamics of Chlorpyrifos in Chinese Cabbage

采用气相色谱法测定不同施药浓度毒死蜱在大白菜中的消解规律。结果表明：毒死蜱在白菜中的半衰期为3．2～3．6 d，在正常喷施浓度下，施药后15天毒死蜱在大白菜中的残留量仍超过我国最高限量标准0．1 mg/kg。用40％毒死蜱乳油防治大白菜害虫，由于地理位置、栽培方式、气候条件、施药浓度、施药次数的不同，安全间隔期差别也较大。

The degradation law of chlorpyrifos at different concentrations in Chinese cabbage was deter -mined by gas chromatography .The results showed that the half -life of chlorpyrifos in Chinese cabbage was 3.2~3.6 days.Under the normal spraying concentration , its residual quantity in Chinese cabbage was still more than 0.1 mg/kg of the highest standard in China after spraying for 15 days.With 40% chlorpyrifos EC against cabbage pests , the safety interval showed larger differences due to different geography location , plant-ing pattern, climate condition, spraying concentration, spraying times.