Kinetics, mechanisms and toxicity of the degradation of imidaclothiz in soil and water

文献类型： 外文期刊

第一作者： Ma, Chang

作者： Ma, Chang;Liu, Xingang;Wu, Xiaohu;Dong, Fengshou;Xu, Jun;Zheng, Yongquan

作者机构：

关键词： Imidaclothiz; Degradation; Metabolite identification; Quantum chemistry; Ecotoxicity

期刊名称：JOURNAL OF HAZARDOUS MATERIALS （ 影响因子：10.588； 五年影响因子：10.129 ）

ISSN： 0304-3894

年卷期： 2021 年 403 卷

页码：

收录情况： SCI

摘要： Hydrolysis and photolysis are important degradation pathways of pesticides while their degradation in soil is a principal metabolic pathway. These processes might generate toxic chemicals and pose threats to the environment. As a member of the controversial neonicotinoid pesticides, the environmental fate and toxicity of imidaclothiz and its potential metabolites have remained ambiguous. Laboratory experiments were conducted to study the degradation kinetics, mechanisms and toxicity of imidaclothiz in aqueous solutions (pH = 4, 7, 9 buffer solutions and ultra-pure water) and soil (black soil, red soil and fluvo-aquic soil) under different conditions (25 degrees C and 50 degrees C). The results showed that imidaclothiz was fairly stable in water and soil under natural conditions. Based on the mass accuracy of the parent chemical and conserved fragment ions, ten candidate degradation products were filtered out using UHPLC-QTOF-MS and the UNIFI system. Then, two of the candidates were synthesized, analysed, and compared with standards to confirm. The microscopic mechanisms of three degradation reactions (imidaclothiz degraded to M216, M216 degraded to M217 and M216 degraded to M198) were elucidated using theoretical calculations. The toxicity data from experiments and the ECOSAR prediction showed that imidaclothiz had low toxicity to Daphnia magna and Danio rerio and had high toxicity to Apis mellifera, with 50% of the degradation products in this study exhibiting higher toxicities to aquatic organisms than the parent chemical.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序