Unravelling psychoactive substances and their metabolites and transformation products: High-Resolution Mass Spectrometry approaches for comprehensive target and suspect screening in wastewater.

ABSTRACT

Untangling the consumption rates of psychiatric drugs and their metabolites/ transformation products-(TPs) through wastewater gains attention lately. However, the potential environmental impact caused by their release remains ambiguous. As it follows, the monitoring of this class of pharmaceuticals as well as the evaluation of their potential toxicity is a matter of high concern. In the light of the above, here, wastewater samples, were collected in a 1-year and a half sampling campaign (2020-2021) and were further subjected to solid phase extraction. A Q Exactive Focus Orbitrap mass analyzer was employed for the analysis of the samples. For the data curation, except of the monitoring of targets, a comprehensive suspect screening workflow was developed and slightly optimized based on a lab made HRMS database for the investigation of legally or illegally prescribed psychiatric drugs and their relevant metabolites/TPs in influents and effluents. Carbamazepine and amisulpride were quantified at the highest mean concentrations 243 and 225 ng/L respectively, in influents. In effluents, the highest mean concentrations were calculated for carbamazepine (180 ng/L) and venlafaxine (117 ng/L). The implementation of suspect screening approach enhanced the comprehensiveness of analysis by detecting 29 compounds not included in the target list. O-Desmethylvenlafaxine was the predominant metabolite in influents presenting a mean concentration equal to 87 ng/L while the same pattern was also noticed in effluents where the mean concentration was up to 91 ng/L. From the group of suspect compounds for which no analytical standards were available, the predominant compounds with detection frequency 100 % were norephedrine and codeine in influents while in effluents, oxazepam was detected in 81 % of the analyzed samples. Finally, in silico and mathematical tools were employed for the assessment of the risk posed to environmental systems. Most of the detected compounds present high risk in all trophic levels.