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Persistence of alprazolam in river water according to forced and non‐forced degradation assays: adsorption to sediment and long‐term degradation products
Author(s) -
Jiménez Juan J.,
Sánchez María I.,
Muñoz Beatriz E.,
Pardo Rafael
Publication year - 2017
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.2148
Subject(s) - alprazolam , chemistry , degradation (telecommunications) , environmental chemistry , forced degradation , surface water , sediment , contamination , chromatography , mass spectrometry , environmental science , environmental engineering , geology , psychology , telecommunications , anxiety , paleontology , ecology , ammonium formate , psychiatry , computer science , biology
Alprazolam is a pharmaceutical compound that it is detected in surface waters. Some degradation studies in aqueous solutions and pharmaceutical products are available, but there is no reliable information about its stability in river water. Here, assays have been conducted under forced biological, photochemical, and thermal conditions, and under non‐forced conditions, to estimate the fate of alprazolam in river water and know its degradation products. The forced assays indicated that the biological and photochemical degradation of alprazolam was negligible; heating at 70°C for a long time barely affected it. The degradation of alprazolam in river water at 100 μg/L was about 5% after 36 weeks, keeping the water under a natural day‐night cycle at room temperature and limiting partially the exposure to sunlight as happens inside a body of water; no change in concentration was observed when the monitoring was performed at 2 μg/L. The results suggest the persistence of alprazolam in surface water and a possible accumulation over time. Residues were monitored by ultra‐pressure liquid chromatography/quadrupole time‐of‐flight/mass spectrometry after solid‐phase extraction; nine degradation products were found and the structures for most of them were proposed from the molecular formulae and fragmentation observed in high‐resolution tandem mass spectra. (5‐chloro‐2‐(3‐methyl‐4H‐1,2,4‐triazol‐4‐yl)phenyl)(phenyl)methanol was the main long‐term transformation product in conditions that simulate those in a mass of water. The degradation rate in presence of sediment was equally very low under non‐forced conditions; adsorption coefficients of alprazolam and major degradation products were calculated. Copyright © 2016 John Wiley & Sons, Ltd.