Development of an analytical method for emerging contaminants including the pharmaceuticals recently selected as key performance indicators of the quaternary treatment of urban wastewater

Abstract

The revised European Directive concerning Urban Wastewater Treatment introduced the quaternary treatment for micropollutants. This directive lists 13 substances used as indicators of the performance of quaternary treatment, including pharmaceuticals such as antihypertensives and antidepressants, as well as some benzotriazoles. This article describes the development of an analytical method to determine these analytes and tire-related contaminants in wastewater and environmental samples. The method involves solid-phase extraction (SPE) followed by liquid chromatography coupled to tandem mass spectrometry (MS/MS) and high-resolution mass spectrometry (QTOF-HRMS). An experimental design is carried out to evaluate the influence of four factors affecting the extraction. Further studies were performed to achieve higher enrichment and thus lower detection limits. The method is validated in terms of analytical figures, and the matrix effect is assessed in water samples of different origins, demonstrating suitability. Real samples were analyzed showing the presence of some of the target compounds in natural waters (sea and river). In the wastewater samples, almost all the substances included in the directive, such as diclofenac, irbesartan or benzotriazole, were detected at levels up to 3 μg L−1. This method will help to assess the risks that the discharge of the targeted contaminants in urban wastewater poses for the environment and public health.