Analysis of emerging illicit drugs in wastewaters by liquid chromatography tandem mass spectrometry.

Abstract

A total of 24 new psychoactive substances were officially notified for the first time in the EU in 2009 through the EWS (Early Warning System), up from 41 in 2010, 49 in 2011 and 73 in 2012 [1]. Illicit drugs are continuously discharged into wastewaters due to human excretion after consumption, occasional direct disposal or clandestine laboratory wastes into sewage systems [2]. Therefore, the analysis of wastewater has the potential to be used as a tool to detect the use of emerging illicit drug in societies. The main objective of this study was to optimize and validate an analytical procedure based on solid phase extraction (SPE) and liquid chromatography triple quadruple mass spectrometry (LC-QqQ-MS/MS), for the simultaneous analysis of 9 emerging illicit drugs and to apply the validated procedure to influent wastewater samples collected from the wastewater treatment plants (WWTPs) in Valencia. The 9 emerging illicit drugs selected were - pyrrolidinopropiophenone (PVP), - pyrrolidinopentiophenone (PPP), 4¿-methyl- -pyrrolidinohexanophenone (MPHP), 4¿-methyl- - pyrrolidinobutiophenone (MPBP), belong to pyrrolidinophenone group, Mephedrone (4MMC), Dibutylone (bk-MMBDB), -Butyrolactone (GBL), 4-Methoxyphencyclidine (4-MeO-PCP) and Bufotenine (BUF). Illicit drugs were extracted from 250 ml of water by SPE using Strata-X cartridges as sorbent. The extract was evaporated to dryness and reconstituted with water-methanol (9:1). Illicit drugs were determined by LC-QqQ-MS/MS using an electrospray ionization source (ESI) in positive ionization mode. Specific MS parameters as ionization mode, collision energy and fragmentor voltage, were optimized for each compound. The fragmentation of the pseudomolecular ion of each compound was performed in multiple reaction monitoring (MRM). The method detection limits ranged from 0.01 to 1.54 ng l-1 and the recoveries from 70 to 120 %, which are appropriate values to identify their presence in wastewater.