Mechanism and kinetics of photochemical transformation of ketoprofen and its degradation intermediates

0498896 - ÚFCH JH 2019 RIV NL eng J - Journal Article
Hykrdová, Lenka - Bajt, O. - Jirkovský, Jaromír
Mechanism and kinetics of photochemical transformation of ketoprofen and its degradation intermediates.
Journal of Hazardous Materials. Roč. 353, JUL 2018 (2018), s. 70-79. ISSN 0304-3894. E-ISSN 1873-3336
Institutional support: RVO:61388955
Keywords : waste-water treatment * nonsteroidal antiinflammatory drugs * endocrine disrupting compounds * sewage-treatment plants * aqueous-solution * benzophenone chromophore * pharmaceutical residues
OECD category: Physical chemistry
Impact factor: 7.650, year: 2018

Ketoprofen, 2-(3-benzoylphenyl)-propionic acid, a widely used non-steroidal anti-inflammatory drug, is considered as an important water pollutant. Kinetics and mechanism of its photolytic transformation in aqueous solutions was studied experimentally and partial reaction steps were modelled by means of quantum chemistry methods. While the rate of ketoprofen photolysis was not significantly affected by its acid-base equilibrium, a marked influence of pH on the subsequent degradation reactions was observed. At pH 1.3, two oxygenated primary products were identified, that underwent fast photolysis. Deprotonated form of ketoprofen was transformed preferentially to ethylbenzophenone and further degradation proceeded substantially slower. Oxygen participated on photolytic processes both as a reactant and the triplet state quencher. The active involvement of water molecules in the reaction mechanism was investigated by comparative experiments in acetonitrile. The phototransformation mechanism proposed based on the experimental data corresponded well with the theoretical results.
Permanent Link: http://hdl.handle.net/11104/0291183