The extensive use of pharmaceuticals became a worldwide environmental issue. Most of these compounds are not
completely removed in wastewater treatment plants and, as a result, they are found in surface and ground water.
In this report the behavior of two drugs, Thioridazine and BG1188 were investigated after their exposure in aqueous
solutions to laser radiation. The degradation processes were monitored using spectroscopic techniques (Absorption
Spectroscopy, Laser Induced Fluorescence, NMR Spectroscopy) and chromatographic methods (HPLC-MS).
The Thioridazine 5x10-2 M solution was irradiated up to 11 min and, respectively, BG1188 10-3 M solution was irradiated up to 30 min, both with 355 nm Nd:YAG pulsed laser beam, with 30 mJ average pulse energy on the sample.
The exposure of Thioridazine solution to laser radiation leads to the appearance of new VIS/NIR absorption peaks, while
the 1H NMR spectrum of 11 min irradiated Thioridazine 5x10-2 M solution indicates modifications both in aliphatic and in aromatic protons regions. The HPLC-MS measurements highlight a change of Thioridazine in two metabolites:
Mesoridazine in the first instance and Sulphoridazine finally. The behavior of the irradiated BG1188 10-3 M solution according to the evolution of the absorption and laser inducedfluorescence spectra highlights a photodecomposition of the initial solution and the appearance of new photoproducts. All the investigated solutions exhibit the photodegradation of the initial compounds, which allows us to consider that the exposure of solutions containing pharmaceutical products to laser beams may constitute a possible mean to remove these kinds of pollutants from different wastewater sources.