Application of LC-MS/MS methods and risk assessment for selected emerging contaminants and their transformation products in a sub-Adriatic river system

Abstract The present study investigates solid-phase extraction (SPE) followed by LC-MS/MS for the analysis of contaminants of emerging concern (CECs) and transformation products (TPs) in the Slovenian-Italian Vipava river system (part of the Adriatic Sea catchment). The adapted method enabled quantitative analysis of 13 various CECs and qualitative analysis of 2 UV filters. SPE recoveries ranged from 17 to 116%, LODs from 0.11 to 5.9 ng L −1 , and overall %RSDs were below 20%. A separate LC-MS/MS method enabled analysis of 42 suspect TPs. Total-ion current LC-MS chromatograms (chemical fingerprints) for river water extracts were also recorded to observe changes along the river course. Ten CECs were frequently detected, and two rosuvastatin TPs, ROS349 and ROS481, were both identified by LC-MS/MS and confirmed with LC-QTOF. Caffeine was the most frequently detected analyte, with average concentrations around 100 ng L −1 , and was even detected in spring water from karst aquifers. Most other CECs were present at higher concentrations near wastewater treatment plants (WWTPs) and landfills. The influence of these two facilities was also observed through chemical fingerprinting. Acesulfame and tris(2-ethylhexyl) phosphate occasionally exceeded 100 ng L −1 . The latter, along with diflufenican (maximum 67 ng L −1 ), resulted in elevated environmental risk quotients. Avobenzone and octocrylene showed higher abundance near WWTPs. Telmisartan and rosuvastatin were quantified at concentrations below 73 and 18 ng L −1 , respectively. Overall, this study expands knowledge of anthropogenic stress on the surface waters in the part of the sub-Adriatic region.