Phototransformation study of the antidepressant paroxetine in surface waters

Abstract In this work, the photochemistry of antidepressant paroxetine (PXT) and its photochemical fate in surface waters were investigated. The direct photolysis quantum yield, as well second-order rate constants reactions between PXT photochemically produced reactive intermediates (i.e., HO•, 3CDOM* 1O2) assessed with steady-state irradiation experiments, while reaction constant CO3•? was known from literature. Using these results, pseudo-first order photodegradation half-life time) modelled a surface-water scenario by varying chemical composition water depth. Nine transformation products identified, formed upon indirect photolysis, pathway proposed that is initiated photohydrolysis to 4-(4-fluorophenyl)-3-(hydroxymethyl)piperidine. results showed reacts HO• radicals approaching diffusion-controlled kinetics, yield ?PXT = (4.03 ± 0.25) × 10?2. Direct together would be main pathways for waters. Reaction particularly important low amounts dissolved organic matter (DOM), high pH inorganic carbon, which are instance typical Slovenia. Finally, little because it significantly inhibited presence antioxidant compounds, reduce partially oxidized back parent PXT.