Photodegradation of antibiotics under simulated solar radiation: implications for their environmental fate

Sci Total Environ. 2014 Feb 1;470-471:299-310. doi: 10.1016/j.scitotenv.2013.09.057. Epub 2013 Oct 18.

Abstract

Roxithromycin, erythromycin, ciprofloxacin and sulfamethoxazole are frequently detected antibiotics in environmental waters. Direct and indirect photolysis of these problematic antibiotics were investigated in pure and natural waters (fresh and salt water) under irradiation of different light sources. Fundamental photolysis parameters such as molar absorption coefficient, quantum yield and first order rate constants are reported and discussed. The antibiotics are degraded fastest under ultraviolet 254 nm, followed by 350 nm and simulated solar radiation. The composition of the matrix (pH, dissolved organic content, chloride ion concentration) played a significant role in the observed photodegradation. Under simulated solar radiation, ciprofloxacin and sulfamethoxazole degrade relatively quickly with half-lives of 0.5 and 1.5h, respectively. However, roxithromycin and erythromycin, macrolides are persistent (half-life: 2.4-10 days) under solar simulation. The transformation products (15) of the targeted antibiotics produced under irradiation experiments were identified using high resolution mass spectrometry and degradation pathways were proposed.

Keywords: Antibiotics; High resolution mass spectrometry; Intermediates; Photodegradation; Photolysis products; Simulated solar radiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / analysis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / radiation effects*
  • Environmental Pollutants / analysis
  • Environmental Pollutants / chemistry
  • Environmental Pollutants / radiation effects*
  • Models, Chemical
  • Photolysis*
  • Sunlight

Substances

  • Anti-Bacterial Agents
  • Environmental Pollutants