[Influence of the coexistence of Zn2+ on the enantioselective toxicity of metolachlor to Scenedesmus obliquus].
To evaluate the enantioselective toxicity of chiral pesticide coexisting with heavy metal, the enantioselective toxicity of Rac-, S-metolachlor alone and coexisting with Zn2+ on Scenedesmus obliquus was studied by using standard toxic testing method. The results showed that the trend of the enantioselective toxicity of Rac- and S-metolachlor coexisting with Zn2+ was similar to that of Rac- and S-metolachlor alone. The growth inhibition rate of Scenedesmus obliquus was decreased by the coexistence of Zn2+ with high concentrations of metolachlor. The inhibition rates with 0.30 mg x L(-1) Rac- and S-metolachlor alone at 24 h were 49.61% and 59.73%, and in the coexistence of Zn2+ the values were 38.41% and 42.52%, respectively. The enantioselective toxicity of Rac- and S-metolachlor was expanded and the toxicity of S-metolachlor increased greater than that of Rac-metolachlor. The coexistence of Zn2+ showed partial increase in toxicity of metolachlor in low concentrations, while there was antagonistic effect in high content of metolachlor. The trend of Chlorophyll content of Scenedesmus obliquus at 96 h was in accordance with the growth inhibition.
Xiao-Na
XN
Hu
Shu-Xian
SX
Zhang
Cai-Dong
CD
Chen
Hui-Jun
HJ
Liu
D000081:Acetamides / Q000633:toxicity*; D002734:Chlorophyll / Q000032:analysis; D006540:Herbicides / Q000633:toxicity*; D044444:Scenedesmus / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity; D015032:Zinc / Q000737:chemistry*
D000081:Acetamides; D006540:Herbicides; D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D015032:Zinc; C051786:metolachlor