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

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 UFLCMS-MS analysis of the photoproducts confirmed the oxidation of the drugs. Finally, a plausible mechanism has been postulated.

Automated summary

This study focuses on the removal of pharmaceuticals belonging to the family of persistent organic pollutants (POPs) using a combination of acetylated riboflavin and visible light. The photodegradation process of carbamazepine and atenolol was achieved in less than 2 hours, with involvement of singlet and triplet excited states of acetylated riboflavin and singlet oxygen. Detailed chemical analysis confirmed the oxidation of the drugs, while a plausible mechanism was proposed.