异丙甲草胺及其S型对映体对蚯蚓的急性毒性差异

采用OECD标准滤纸接触法、人工土壤法及自然土壤法研究了异丙甲草胺及其S型对映体对蚯蚓的急性致死作用及手性差异.结果表明,3种方法相比较,滤纸染毒法结果置信区间最大,可靠性较差.自然土壤中Rac-异丙甲草胺及S-异丙甲草胺对蚯蚓的急性毒性大于人工土壤;根据毒性分级,Rac-异丙甲草胺及其S型对映体均属于低毒级农药;3种试验方法所得的Rac-异丙甲草胺及S-异丙甲草胺对蚯蚓的LC50差别不大,表明这2种农药对蚯蚓急性毒性的手性差异较小.

Acute toxicity difference of metolachlor and its S-isomer on earthworms

The acute lethal effect of metolachlor and its S-isomer on earthworms with the chiral difference was analyzed by using the methods of standard OECD filter paper test, artificial soil test and natural soil test. The confidence interval of filter paper toxicity test was the widest and therefore the method was not so reliable. The acute toxicity of Rac- metolachlor and S-isomer on earthworms in the natural soil test was larger than that in the artificial soil test. According to the classification criteria of the toxic chemicals, Rac-metolachlor and S-isomer should belonged to the low poisonous pesticides. There were little differences in LC50 of Rac-metolachlor and S-isomer on earthworms, which showed that the chiral difference of the two pesticides on the acute toxicity of earthworms was insignificant.