Photocatalytic degradation of drugs in water mediated by acetylated riboflavin and visible light: A mechanistic study

J Photochem Photobiol B. 2021 Aug:221:112250. doi: 10.1016/j.jphotobiol.2021.112250. Epub 2021 Jun 29.

Abstract

There is a current concern, among the scientific community, on the pollutants classified as "persistent organic pollutants (POPs)". Pharmaceuticals and personal care products (PPCPs) belong to this family of contaminants; therefore, it is necessary to find more efficient techniques able to achieve their removal from the environment. This study focuses on two different pharmaceuticals: carbamazepine and atenolol, chosen for their widespread use and their different chemical and medical properties. In this work, an organic dye, acetylated riboflavin, has been used in combination with visible light to achieve the photodegradation of these two POPs in <2 h. Moreover, photophysical experiments demonstrated the involvement of the singlet and triplet excited states of acetylated riboflavin and the generated singlet oxygen in the removal of these drugs. Besides, a detailed UFLC-MS-MS analysis of the photoproducts confirmed the oxidation of the drugs. Finally, a plausible mechanism has been postulated.

Keywords: Electron transfer; Organic dye; Photodegradation products; Singlet oxygen; Visible light.

MeSH terms

  • Acetylation
  • Atenolol / chemistry
  • Carbamazepine / chemistry*
  • Catalysis
  • Kinetics
  • Light*
  • Photolysis / drug effects
  • Photolysis / radiation effects*
  • Riboflavin / chemistry*
  • Singlet Oxygen / chemistry
  • Water Pollutants, Chemical / chemistry*
  • Water Pollutants, Chemical / metabolism

Substances

  • Water Pollutants, Chemical
  • Singlet Oxygen
  • Carbamazepine
  • Atenolol
  • Riboflavin