Multi-residue analysis of pharmaceuticals in wastewater by liquid chromatography–magnetic sector mass spectrometry: Method quality assessment and application in a Belgian case study

Through systematic research a novel analytical method using solid-phase extraction (SPE) and liquid chromatography magnetic sector mass spectrometry was developed for the measurement of 43 pharmaceuticals in wastewater. A thorough method validation quantified the contribution of both the extraction recovery and matrix effects in the overall method process efficiency, and a detailed uncertainty analysis was performed to elaborate a quality labelling strategy to be used in data interpretation. Compounds for which a precise (relative standard deviation <20%) process efficiency between 60% and 140% was determined, were labelled as ‘quantitative’ whereas the results for other compounds should be interpreted as ‘indicative’.Method application on influent and effluent samples of (i) a conventional active sludge system and (ii) a parallel membrane bioreactor/conventional active sludge wastewater treatment plant in Belgium revealed the occurrence of 22 pharmaceuticals. The anti-inflammatory drug diclofenac and the antidepressant venlafaxine were measured in the effluents at concentrations ranging from 0.5 to 1.8 μg L−1 and 0.2 to 0.5 μg L−1, respectively, which indicated to be of high potential environmental risk for the receiving river Dender, Belgium.