Characterization of phenazone transformation products on light‐activated TiO₂ surface by high‐resolution mass spectrometry

Abstract

The paper examines the transformation of phenazone (2,3-dimethyl-1-phenyl-3-pyrazolin-5-one), a widely used analgesic and antipyretic drug, under simulated solar irradiation in pure water, using titanium dioxide, and in river water. High-resolution mass spectrometry was employed to monitor the evolution of photoinduced processes. Initially, laboratory experiments were performed to simulate drug-transformation pathways in aqueous solution, using TiO(2) as photocatalyst. Thirteen main phenazone transformation products were detected, and full analysis of their MS and MS(n) spectra identified the diverse isobaric species. All these transformation products were themselves easily degraded, and no compounds were recognized to remain until 1h of irradiation. From these findings, a tentative degradation pathway is proposed to account for the photoinduced transformation of phenazone in natural waters. These simulation experiments were verified in the field, seeking phenazone in River Po water samples.

Water Analysis: Emerging Contaminants and Current Issues

“…Calza et al reported the conversion of carbamazepine and clarithromycin in purified water using heterogeneous photocatalysis with TiO 2 . 96 For carbamazepine, 28 TPs were identified via MS fragmentation using LC/LTQ-Orbitrap-MS, formed by mono-, di-, trihydroxylation, oxidation, and ring contractions, leading to derivatives of 9-N-aminocarbonylacridine-9-carboxaldehydes. Similar reactions (hydroxylations, oxidations) and the cleavage of the sugar moiety cladinose led to the formation of 29 TPs when the macrolide antibiotic clarithromycin was present.…”

“…Calza et al reported the conversion of carbamazepine and clarithromycin in purified water using heterogeneous photocatalysis with TiO 2 . For carbamazepine, 28 TPs were identified via MS fragmentation using LC/LTQ-Orbitrap-MS, formed by mono-, di-, trihydroxylation, oxidation, and ring contractions, leading to derivatives of 9- N -aminocarbonylacridine-9-carboxaldehydes.…”

Identification of the unknown transformation products derived from clarithromycin and carbamazepine using liquid chromatography/high‐resolution mass spectrometry

“…[23][24][25][26] Mass spectrometry (MS) is the most selective technique to identify unknown compounds and, using electrospray ionization (ESI)-MS, it is possible to obtain structurally significant fragment ions. [27][28][29][30] Degradation products were characterized by multiple stage mass spectrometry (MS n ), using a high-resolution ion trap (LTQ-Orbitrap), acquiring spectra at a resolving power of 30 000, in order to confirm the elemental composition, together with high-resolution MS n detection, which provides diagnostic identification and characterization of metabolites.…”

Hydroxyl radical induced oxidation of theophylline in water: a kinetic and mechanistic study

“…Hydroxyl radicals ( • OH) are the key species responsible for the oxidative destruction of environmental pollutants in many Advanced Oxidation Processes (AOPs) such as TiO 2 photocatalysis, H 2 O 2 /UV photolysis, sonolysis, γ-radiolysis etc., [1][2][3][4][5][6][7] and many biological processes including DNA damage, mutation and ageing. [8][9][10][11][12][13][14][15][16] The • OH induced destruction of emerging organic pollutants has been widely experimented [1][2][3][4]7,17,18 since the presence of pharmaceutically active compounds in the aquatic environment became an emerging environmental issue. [19][20][21][22] Pulse radiolysis studies reveal that • OH reacts with a large number of organic molecules with a nearly diffusion controlled rate.…”

“…[19][20][21][22] Pulse radiolysis studies reveal that • OH reacts with a large number of organic molecules with a nearly diffusion controlled rate. 5,6,12,15,23,24 Furthermore, the ability to achieve complete mineralization 2,6 makes techniques of these kinds acceptable and environmentally friendly.…”