Detection of halogenated pharmaceuticals and their transformation products in freshwater ecosystem by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) using suspect screening approach

Abstract

The ongoing release of contaminants of emerging concern (CECs) into the aquatic environment as result of anthropogenic activities has attracted attention of the international scientific community because of their widespread occurrence, environmental recalcitrance and their possible effects in biota. Pharmaceuticals are one of the groups defined as CECs which nature may also have unintended effects on animals and microorganisms in the environment, with highlight to the organohalogenated compounds. After their ingestion, pharmaceuticals reach the environment through discharges of wastewater treatment plants (WWTP). The environmental persistence of organohalogenated compounds was already proved by many studies of pesticides, flame retardants and polymers, but not for halogenated pharmaceuticals. Once in the aquatic environment they can undergo transformation through biotic and abiotic processes. Photolysis is one of the major elimination/transformation processes of pharmaceuticals in rivers. If the pharmaceutical is transformed, it can be rarely mineralized or be transformed to a transformation product (TP). Owing the expected low concentrations for these TPs, very sensitive and selective techniques for their separation and identification are need, as liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The present project aims to study the photodegradability of halogenated pharmaceuticals and their detection, as well as their TPs, in treated effluents and river water/sediment samples, through LC-HRMS using suspect screening approach