Investigating in-sewer transformation products formed from synthetic cathinones and phenethylamines using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

Juliet Kinyua; Noelia Negreira; Ann-Kathrin McCall; Tim Boogaerts; Christoph Ort; Adrian Covaci; Alexander L N van Nuijs

doi:10.1016/j.scitotenv.2018.03.253

Investigating in-sewer transformation products formed from synthetic cathinones and phenethylamines using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

Sci Total Environ. 2018 Sep 1:634:331-340. doi: 10.1016/j.scitotenv.2018.03.253. Epub 2018 Apr 6.

Authors

Juliet Kinyua¹, Noelia Negreira², Ann-Kathrin McCall³, Tim Boogaerts², Christoph Ort³, Adrian Covaci², Alexander L N van Nuijs²

Affiliations

¹ Toxicological Center, Department of Pharmaceutical Sciences, Campus Drie Eiken, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium. Electronic address: juliet.kinyua@outlook.com.
² Toxicological Center, Department of Pharmaceutical Sciences, Campus Drie Eiken, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium.
³ Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600, Dübendorf, Switzerland.

PMID: 29627557
DOI: 10.1016/j.scitotenv.2018.03.253

Abstract

Recent studies have demonstrated the role of biofilms on the stability of drug residues in wastewater. These factors are pertinent in wastewater-based epidemiology (WBE) when estimating community-level drug use. However, there is scarce information on the biotransformation of drug residues in the presence of biofilms and the potential use of transformation products (TPs) as biomarkers in WBE. The purpose of this work was to investigate the formation of TPs in sewage reactors in the presence of biofilm mimicking conditions during in-sewer transport. Synthetic cathinones (methylenedioxypyrovalerone, methylone, mephedrone) and phenethylamines (4-methoxy-methamphetamine and 4-methoxyamphetamine) were incubated in individual reactors over a 24h period. Analysis of parent species and TPs was carried out using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QToFMS). Identification of TPs was done using suspect and non-target workflows. In total, 18 TPs were detected and identified with reduction of β-keto group, demethylenation, demethylation, and hydroxylation reactions observed for the synthetic cathinones. For the phenethylamines, N- and O-demethylation reactions were identified. Overall, the experiments showed varying stability for the parent species in wastewater in the presence of biofilms. The newly identified isomeric forms of TPs particularly for methylone and mephedrone can be used as potential target biomarkers for WBE studies due to their specificity and detectability within a 24h residence time.

Keywords: Biofilm; Biomarkers; LC-QToFMS; New psychoactive substances; Stability; Wastewater-based epidemiology.