Speaker
Description
Per- and polyfluoroalkyl substances (PFAS) are among the most challenging contaminants of emerging concern due to their persistence, structural diversity, and complex toxicological profiles. Their widespread use has led to global occurrence in aquatic environments, while differences in physicochemical properties across the PFAS class complicate both monitoring and environmental interpretation. This lecture presents a stepwise framework for tracking PFAS in surface waters, beginning with high-resolution mass spectrometry (HRMS)-based suspect screening analysis to expand PFAS coverage beyond conventional target lists and capture known, emerging, and previously overlooked PFAS. Screening results are then linked to hazard- and exposure-based prioritisation, integrating QSAR-derived indicators of persistence, bioaccumulation, and toxicity with occurrence-related metrics such as detection frequency and concentration magnitude. This prioritisation step supports the identification of the most relevant PFAS for follow-up analysis. A subset of prioritised compounds was then selected for targeted (semi)quantification based on both prioritisation outcomes and the availability of analytical standards, enabling experimental confirmation and refinement of the assessment. The approach is illustrated through recent investigations¹ of urban-impacted river systems in Serbia, representing one of the first comprehensive PFAS assessments in this part of the Danube River Basin. Initial HRMS screening revealed additional PFAS beyond the conventional target list, including ultra-short-chain compounds i.e. trifluoroacetic acid (TFA), which has recently gained particular regulatory relevance in the EU and was often detected at higher levels than legacy PFAS. Overall, the lecture demonstrates how a workflow progressing from broad screening to prioritisation and targeted confirmation can strengthen PFAS monitoring and provide a more robust basis for environmental risk assessment and regulatory decision-making.