Occurrence of drugs of abuse and benzodiazepines in river waters from the Madrid Region (Central Spain)

Abstract

This work investigates, for the first time, the occurrence of 10 drugs of abuse, six metabolites, and three benzodiazepines in surface waters from the Jarama and Manzanares Rivers in the Madrid Region, the most densely populated area in Spain and one of the most densely populated in Europe. The results of this study have shown the presence of 14 out of the 19 compounds analyzed at concentrations ranging from 1.45 to 1020 ng L(-1). The most ubiquitous compounds, found in 100% of the samples, were the cocaine metabolite benzoylecgonine (BE), the amphetamine-like compound ephedrine (EPH), the opioids morphine (MOR), methadone (METH), and the METH metabolite 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and the three investigated benzodiazepines alprazolam (ALP), diazepam (DIA) and lorazepam (LOR). Meanwhile, the largest concentrations observed corresponded to EPH (up to 1020 ng L(-1)), BE (823 ng L(-1)), EDDP (151 ng L(-1)), and LOR (167 ng L(-1)). The only not detected compounds were heroin (HER) and its metabolite 6-acetylmorphine (6ACM), lysergic acid diethylamide (LSD) and its metabolite 2-oxo-3-hydroxy-LSD (OH-LSD), and Δ(9)-tetrahydrocannabinol (THC). Overall, the levels measured are comparatively higher than those previously reported in Europe. Comparison of the results obtained for samples collected on different days (Thursday and Sunday) did not show meaningful differences between weekdays and weekends. The lack of (eco)toxicological data does not permit to predict or disregard potential adverse effects on wildlife. Risk assessment in humans would require further knowledge, not currently available, on exposure to these compounds through other routes like drinking water and/or food.

Keywords: 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol; 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine; 2-oxo-3-hydroxy-LSD; 3,4-methylenedioxymethamphetamine; 6-acetylmorphine; 6ACM; ALP; AM; ATS; BE; Benzodiazepines; CE; CO; DAs; DIA; Drugs of abuse; EDDP; EPH; EPs; HER; IDA; Jarama and Manzanares Rivers; LC; LOD; LOQ; LOR; LSD; Ldet; MA; MDMA; METH; MOR; MR; MS; Madrid Region; Madrid Region, MS/MS, tandem mass spectrometry; OH-LSD; RSP; SPE; SRM; STP; Spain; Surface water; THC; THC-COOH; UNODC; United Nations Office on Drugs and Crime; alprazolam; amphetamine; amphetamine-type stimulants; benzoylecgonine; cocaethylene; cocaine; diazepam; drugs of abuse; emerging pollutants; ephedrine; heroin; information-dependent acquisition; limit of detection; limit of determination; limit of quantification; liquid chromatography; lorazepam; lysergic acid diethylamide; mass spectrometry; methadone; methamphetamine; morphine; n.a.; n.c.; n.d.; not available; not confirmed; not detected; river sampling point; selected reaction monitoring; sewage treatment plant; solid phase extraction; Δ(9)-tetrahydrocannabinol.