Wide-Scope Determination of Pharmaceuticals and Pesticides in Water Samples: Qualitative and Confirmatory Screening Method Using LC-qTOF-MS

Aquatic system contamination is a subject of concern due to the high number of contaminants with the potential to be hazardous for plant and animal species, including humans. A large number of analytical methods have been developed to evaluate the extension of water resource pollution, most of them focused on target residue analysis. Screening methods for potential target and non-target compounds are a potential alternative and could be used for a comprehensive evaluation of samples composition. Liquid chromatography coupled to time of flight mass spectrometry (LC-qTOF-MS/MS) was developed to provide full-spectrum data and high mass resolution with appropriate selectivity and sensitivity for monitoring of 300 pharmaceuticals and pesticides in environmental water samples. The validation was based on anti-doping analysis validation protocols, using three different concentration levels (0.01, 0.1, and 1.0 μg L⁻¹). Confirmation analysis was achieved using two fragment ions monitoring for each analyte. Samples were extracted by solid-phase extraction and analyzed by LC-qTOF-MS/MS. The final method was able to detect 170 chemicals in wastewater treatment plant effluent and 198 chemicals in surface water. The advantage of using post-acquisition data processing provided by a qTOF-MS/MS system allowed for non-target analysis for an illicit drug metabolite determination. The method was successfully applied to real samples of wastewater and surface water.