Photodegradation fate of different dissociation species of antidepressant paroxetine and the effects of metal ion Mg2+: Theoretical basis for direct and indirect photolysis

被引：1

作者：

Lu Y. ^{[1
]}

Wang S. ^{[1
]}

Shen Y. ^{[1
]}

Hao C. ^{[2
]}

机构：

[1] School of Environmental Science and Engineering, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Scie

[2] State Key Laboratory of Fine Chemicals, Dalian University of Technology, Liaoning, Dalian

来源：

Chemosphere | 2023年 / 335卷

基金：

中国国家自然科学基金;

关键词：

Density functional theory; Hydroxyl radical; Mg[!sup]2+[!/sup; Paroxetine; Photodegradation; Singlet oxygen;

D O I：

10.1016/j.chemosphere.2023.139070

中图分类号：

学科分类号：

摘要：

Paroxetine (abbreviated as PXT) has been widely used as one of the standard antidepressants for the treatment of depression. PXT has been detected in the aqueous environment. However, the photodegradation mechanism of PXT remains unclear. The present study aimed to use density functional theory and time-dependent density functional theory to study the photodegradation process of two dissociated forms of PXT in water. The main mechanisms include direct and indirect photodegradation via reaction with ·OH and 1O2 and photodegradation mediated by the metal ion Mg2+. Based on the calculations, PXT and PXT-Mg2+ complexes in water are photodegraded mainly indirectly and directly. It was found that PXT and PXT-Mg2+ complexes were photodegraded by H-abstraction, OH-addition and F-substitution. The main reaction of PXT indirect photolysis is OH-addition reaction, while the main reaction of PXT0-Mg2+ complex is H-abstraction. All the reaction pathways of H-abstraction, OH-addition and F-substitution are exothermic. PXT0 reacts more readily with ·OH or 1O2 in water than PXT+. However, the higher activation energy of PXT with 1O2 indicates that the 1O2 reaction plays a minor role in the photodegradation pathway. The direct photolysis process of PXT includes ether bond cleavage, defluorination, and dioxolane ring-opening reaction. In the PXT-Mg2+ complex, the direct photolysis process occurs via a dioxolane ring opening. Additionally, Mg2+ in water has a dual effect on the direct and indirect photolysis of PXT. In other words, Mg2+ can inhibit or promote their photolytic reactions. Overall, PXT in natural water mainly undergo direct and indirect photolysis reactions with ·OH. The main products include direct photodegradation products, hydroxyl addition products and F-substitution products. These findings provide critical information for predicting the environmental behavior and transformation of antidepressants. © 2023

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