Analysis of llicit and illicit drugs in waste, surface and lake water samples using large volume direct injection high performance liquid chromatography – Electrospray tandem mass spectrometry (HPLC–MS/MS)

Llicit and illicit drugs represent a recent group of emerging contaminants and have been found in the aquatic environment. A HPLC–MS/MS method was developed using direct injection (DI) of larger volumes and a polar endcapped reversed-phase (RP) column to measure drug components in water samples belonging to the cocaine group, opiates, amphetamine-like stimulants and metabolites thereof. After validation, including sensitivity, linearity, recovery, precision and matrix effect studies, most drugs could be detected with limits of quantitation (LOQ) of 20 ng L−1 in wastewater (WW) and 0.2 ng L−1 in surface water. The major substances found in influents and effluents were cocaine (COC), benzoylecgonine (BE), morphine (MO), methadone (MD) and its main metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) with concentrations up to 2 μg L−1, followed by codeine (COD) and the amphetamines which ranged between 20 and 400 ng L−1. Except for MO, COD and EDDP levels were generally lower in the effluents. River and lake water contained trace amounts of mainly BE, MD and EDDP from the high pg L−1 to the low ng L−1 level. Monitoring COC and BE levels over 11 consecutive days in influents and effluents suggests a consumption preference on week-end days. Finally, measuring an influent after a major music event revealed that sewage treatment plants (STPs) are exposed, for a limited period of time, to high concentration peaks of COC and BE as well as amphetamine-like stimulants such as ecstasy (MDMA).