Identifying the Degradation Products of Dexamethasone for COVID‐19 Treatment in Mexico City's Wastewater: Theory and Experiments

Abstract

AbstractQuantum chemistry calculations were performed to elucidate the reaction sites and degradation routes of dexamethasone. Flow Injection Analysis Electrospray Fourier‐Transform Ion Cyclotron Resonance Mass Spectrometry (FIA‐ESI‐FTCIR‐MS) was used to identify dexamethasone and its byproducts in Mexico City's wastewater, guided by results from ab‐initio calculations on the bond energy analysis and thus propose possible degradation routes. Products of hydroxylation/reduction, decarbonylation/formylation and defluorination reactions were identified. The results of this study contribute to the identification of the degradation products of drugs commonly used in the treatment of COVID‐19 in urban areas. Through wastewater analysis and computationally assisted Mass‐Spectrometry techniques, an alternative approach is presented to identify byproducts in complex matrices when analytical standards are unavailable or in case of limited understanding on the stability of the degradation byproducts in aqueous medium.