Metoprolol and metoprolol acid degradation in UV/H2O2 treated wastewaters: An integrated screening approach for the identification of hazardous transformation products

Highlights: • Development of an integrated screening methodology for detection of hazardous TPs. • Degradation and transformation of MTP and MTPA in UV/H₂O₂ experiments. • Tentative identification of 24 TPs from MTP and MTPA photo-oxidation. • Overview of the TPs generated in pure water, hospital and industrial wastewater. • Ecotoxicity of the compounds identified using in silico and in vitro experiments. -- Abstract: Advancements on analytical strategies to determine the chemicals present in treated wastewater are necessary to clearly link their occurrence with the ecotoxicity of such effluents. This study describes the development of an integrated screening approach to determine the highest number of pharmaceutical transformation products (TPs) in a single run. The identification of TPs was based on the comparison of detected features with literature sources, compound prediction tools, in-house libraries and reference standards using high-resolution mass spectrometry (HRMS). This integrated approach allowed a better estimation (in silico) of the ecotoxicological contribution of the individual TPs identified. As a proof of concept, this methodology was applied for identification of the TPs generated from metoprolol and its main human metabolite (metoprolol acid) in pure water, hospital wastewater and industrial wastewater treated by UV/H₂O₂. Twenty-four TPs with potential ecotoxicological implications were identified and their presence was pinpointed as a function of the treated wastewater. An integrated screening approach has been developed using four different screening methodologies in the same run. Additionally, the metabolite MTPA has been considered as a target pollutant in UV/H₂O₂ experiments.