当前位置: X-MOL 学术J. Hazard. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Kinetics, mechanisms and toxicity of the degradation of imidaclothiz in soil and water
Journal of Hazardous Materials ( IF 12.2 ) Pub Date : 2020-09-19 , DOI: 10.1016/j.jhazmat.2020.124033
Chang Ma , Xingang Liu , Xiaohu Wu , Fengshou Dong , Jun Xu , Yongquan Zheng

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 ℃ and 50 ℃). 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.



中文翻译:

Imidaclothiz在土壤和水中降解的动力学,机理和毒性

水解和光解是农药的重要降解途径,而农药在土壤中的降解是主要的代谢途径。这些过程可能会产生有毒化学物质,并对环境构成威胁。作为有争议的新烟碱类农药的一员,依米达布尼兹及其潜在代谢产物的环境命运和毒性仍然不明确。进行了室内实验,研究了在不同条件下,水溶液(pH = 4,7,9缓冲溶液和超纯水)和土壤(黑土,红土和潮土)中咪达木霉的降解动力学,机理和毒性。条件(25℃和50℃)。结果表明,imidaclothiz在自然条件下在水和土壤中相当稳定。根据母化学物质和保守碎片离子的质量精度,使用UHPLC-QTOF-MS和UNIFI系统过滤掉十种候选降解产物。然后,将其中的两个候选者进行合成,分析并与标准进行比较以进行确认。使用理论计算阐明了三个降解反应的微观机理(imidaclothiz降解为M216,M216降解为M217和M216降解为M198)。实验和ECOSAR预测的毒性数据表明,imidaclothiz对大型蚤(Daphnia magna)和Danio rerio的毒性较低,而对Daphnia mario和Danio rerio的毒性较高。使用理论计算阐明了降解为M217的M216和降解为M198的M216。实验和ECOSAR预测的毒性数据表明,imidaclothiz对大型蚤(Daphnia magna)和Danio rerio具有低毒性,而对Daphnia magna和Danio rerio具有低毒性。使用理论计算阐明了降解为M217的M216和降解为M198的M216。实验和ECOSAR预测的毒性数据表明,imidaclothiz对大型蚤(Daphnia magna)和Danio rerio的毒性较低,而对Daphnia mario和Danio rerio的毒性较高。蜜蜂(Apis mellifera),在这项研究中,降解产物的50%比母体化学品对水生生物具有更高的毒性。

更新日期:2020-09-20
down
wechat
bug