Photodegradation of fluoroquinolone antibiotic gatifloxacin in aqueous solutions

Abstract

Fluoroquinolone antibiotics (FQs) are frequently detected as emerging pollutants in aqueous environments. In this study, kinetics, influencing factors and mechanisms on the photodegradation of gatifloxacin, a representative FQ, were investigated. The photodegradation follows the pseudo-first-order kinetics. Gatifloxacin photodegrades with a quantum yield of (5.94 ± 0.95) × 10 −3 in pure water and undergoes direct photolysis as well as self-sensitized photodegradation. The FQ photodegrades slower in freshwater and seawater than in pure water, which is attributed to the integrative effects of pH and the aqueous dissolved matter (e.g., humic acids and NO 3 − ) on the photodegradation. A toxicity test using Vibrio fischeri revealed the formation of hazardous photoproducts. gatifloxacin, photodegradation, influencing factors, reactive oxygen speciesCitation: Ge L K, Chen J W, Zhang S Y, et al. Photodegradation of fluoroquinolone antibiotic gatifloxacin in aqueous solutions.

Diclofenac photodegradation under simulated sunlight: Effect of different forms of nitrogen and Kinetics

“…The degradation process has been referred to as the self-sensitized photooxidation of pollutants [25][26][27]. It is therefore possible that the photodegradation of DCF includes a self-sensitization photooxidation process via •OH, 1 O 2 and O 2 •− under simulated sunlight.…”

Photodegradation of Fleroxacin Injection: II. Kinetics and Toxicological Evaluation

“…In most researches on photo-decomposition of drugs, samples were always confined to diluted solutions (16,17). Most of the degradation processes followed first-order reaction relationship (18), while few (as abeprazole methanolic solutions, 0.8 mg/ mL) showed zero-order kinetics (14).…”

Photosensitizing Mechanism and Identification of Levofloxacin Photoproducts at Ambient UV Radiation

“…Due to the complexity of biological system, it is difficult to demonstrate clearly the specific role of ROS in the manifestation of phototoxicity in in vivo studies. Drug induced phototoxicity is associated with the formation of toxic photoproducts or the generation of short‐lived intermediates, increased levels of ROS within the skin and may induced skin diseases (41), earlier study of a photosensitive drug under sunlight revealed direct photolysis as well as self‐sensitized photolysis via ˙OH and 1 O 2 (42). Our results demonstrate that LVFX generates 1 O 2 under UV‐R/sunlight exposure which is responsible for photodegradation and photoproducts formation.…”