4种农药对水中咪鲜胺光降解的影响

Effects of Four Pesticides on Photo-Degradation of Prochloraz in Water

利用气相色谱仪建立了水中咪鲜胺残留量的分析检测方法,在此基础上研究了4种常用农药(三唑磷、氯氰菊酯、碘甲磺隆钠盐和抗蚜威)对水中咪鲜胺光化学降解的影响。结果表明:①水中的咪鲜胺可用石油醚∶丙酮(9∶1,V/V)混合液提取,提取液经浓缩后用正己烷定容,GC-ECD(Ni63)检测;当添加浓度为0.027、0.054、0.108、0.216mg·L-1时,添加回收率为89.77%￣102.65%,变异系数为3.82%￣4.85%,最小检出量为1.08×10-11g,最小检出浓度为0.0027mg·L-1。②三唑磷、氯氰菊酯、碘甲磺隆钠盐能抑制水中咪鲜胺的光化学降解,抑制作用的大小顺序为:碘甲磺隆钠盐垌氯氰菊酯>三唑磷,而且抑制作用的强弱还与这3种农药在水中的浓度成正相关。③抗蚜威能加速水中咪鲜胺的光化学降解,说明抗蚜威具有光敏化作用,而且光敏化作用的大小与水中抗蚜威的浓度成正相关。试验结果说明不同种类的农药对咪鲜胺的光化学降解有不同的效应,因此,在评价咪鲜胺的生态环境行为与效应时,不仅要了解咪鲜胺自身的特点与性质,还应充分考虑实际环境中共存农药等物质的影响。

An analytical method for residue of prochloraz fungicide in water was established by gas chromatography. Applying this method, the respective effect of four pesticides-triazophos, cypermethrin, pirimicarb, iodosulfuron-methyl-sodium on photodegradation of proehloraz was studied under the illumination of high-pressure mercury lamp. The result that： ①the residue of proehloraz in water was extracted with petroleum ether and acetone （9：1,V/V）. After being concentrated by evaporation, the extract fixed volume to 5.0 mL, and was detected by gas chromatography with electron capture detection. Recoveries from untreated control samples fortified with prochloraz at levels of 0.027, 0.054, 0.108 and 0.216 mg. L^-1 ranged from 89.77% to 102.65%, and the coefficient of variation was from 3.82% to 4.85%. The lowest detectable quantity was 1.08×10^-11g, and the limit of detection was 0.027 mg·L^-1 ②Triazophos, cypermethrin, iodosuffuron-methyl-sodium can inhibit the photo-degradation of prochloraz in water.The inhibition of those three pesticides was found to be in an order： Iodosuffuron-methyl-sodium〉cypermethrin〉triazophos, and the inhibition intensity was in positive correlation with its concentration in water. ③ Pirimicarb can accelerate the photo-degradation of prochloraz in water, and display a photosensitive effect on the photo-degradation of prochloraz. In the meantime, this photosensitive effect has a positive correlation with the concentration of pirimicarb in water. It may be concluded that the different pesticide had respective effect on the photo-degradation of prochloraz in water. Therefore, when assessing the environmental behavior and effect of prochloraz, it is also vital to consider the influence of co-existing pesticides.