Illicit drugs of emerging concern in surface and wastewater

Abstract

A monitoring program was undertaken in Valencia in Spain to determine the fate of emerging illicit drugs in three contrasting wastewater plants utilizing different wastewater treatment technologies. The impact of treated wastewater effluent on the quality of receiving waters was also assessed. Samples were collected at 25 sites through the Turia River Basin and wastewater samples were collected from the influent of three wastewater treatment plants (WWTPs) in Valencia. The 8 emerging illicit drugs selected for this study were ?-pyrrolidinopropiophenone, ?- pyrrolidino-pentiophenone, 4¿-methyl- ?-pyrrolidinohexanophenone, 4¿-methyl- ?- pyrro-lidinobutiophenone, belong to pyrrolidinophenone group, Mephedrone, Dibutylone, 4-Methoxyphencyclidine and Bufotenine. Illicit drugs were extracted from 250 ml of water by solid phase extraction (SPE) and determined by liquid chromatography triple quadruple mass spectrometry (LC-QqQMS/MS) using an electrospray ionization source (ESI) in positive ionization mode. The method detection limits ranged from 0.01 to 1.54 ng L-1 and the recoveries from 57 to 127 % with relative standard deviations ¿ 20 %. The feasibility of this method was demonstrated by analyzing spiked water samples. Their application to determine new illicit drugs in the influent of the selected WWTP shows the presence of bufotenine in all samples (at concentrations up to 325 ng L-1) and 4¿-methyl- ?- pyrro-lidinobutiophenone in 24 % (at concentration up to 240 ng L-1). Also, bufotenine was detected at 7 sampling points of the Turia River Basin at concentrations ranging from 4 to 67 ng L-1 and 4¿-methyl-?- pyrro-lidinobutiophenone was detected only in one point at 38 ng L-1 for BUF. The others illicit drugs analyzed were not detected neither in the influent of WWTPs nor in Turia River Basin. To our knowledge, it is the first time that these drugs were detected and monitored in River Basins. This study also highlights the need of future research regarding these drug¿s transformation pathways and their ecotoxicological effects.