Photodegradation of Mefenamic Acid in Aqueous Media: Kinetics, Toxicity and Photolysis Products.
The present study investigated the photolytic behavior and photodegradation products of mefenamic acid (MEF) under ultraviolet-C irradiation. The results demonstrated that the photodegradation of MEF followed pseudo-first-order kinetics and the direct photolysis quantum yield of mefenamic acid was observed to be 2.63 ± 0.28 × 10⁻³. Photodegradation of MEF included degradation by direct photolysis and by self-sensitization that the contribution rates of self-sensitized photodegradation were 5.70, 11.25 and 18.96 % for ·OH, ¹O₂ and O·₂⁻ , respectively. Primary transformation products of MEF were identified using ultra performance liquid chromatography and quadrupole time-of-flight mass spectrometer (UPLC-Q-TOF-MS). The identified transformation products suggested three possible pathways of MEF photodegradation: dehydrogenation, hydroxylation, and ketonized reactions. Toxicity of phototransformation products were evaluated using the Microtox test, which revealed that photodegradation likely provides a critical pathway for MEF toxicity reduction in drinking water and wastewater treatment facilities.
Ping
P
Chen
Feng Liang
FL
Wang
Kun
K
Yao
Jing Shuai
JS
Ma
Fu Hua
FH
Li
Wen Ying
WY
Lv
Guo Guang
GG
Liu
D007700:Kinetics; D013058:Mass Spectrometry; D008528:Mefenamic Acid / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D010782:Photolysis; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects
D014874:Water Pollutants, Chemical; D014867:Water; D008528:Mefenamic Acid