Suspect screening and quantitative analysis of 165 contaminants of emerging concern in water, sediments, and biota using LC-MS/MS: Ecotoxicological and human health risk assessment.

This study aimed to implement a targeted multiple reaction monitoring (MRM) screening strategy using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for the initial detection of 165 compounds of emerging concern (CECs) in water, sediment, and fish samples. Following the screening, confirmatory and quantitative analyses were conducted using analytical standards for the detected compounds. Qualitative results were confirmed using high-resolution mass spectrometry (HRMS) for those CECs without available standards. Ecotoxicological and human health risk assessments were performed for the quantified CECs. The analysis identified 35 suspect CECs (12 quantified with analytical standards), including parent compounds and metabolites of anti-inflammatories, antibiotics, antidepressants, sedatives, stimulants, and illicit drugs. High concentrations of these CECs were particularly evident near a Wastewater Treatment Plant (WWTP), where notable levels of compounds such as caffeine (4.02-15.03 ng L^-1), ciprofloxacin (6.05 ng L^-1), clindamycin (6.04-7.01 ng L^-1), and diclofenac (1.36-2.20 ng L^-1) were detected. Sediment samples exhibited the highest incidence of CECs, with caffeine reaching the highest concentration (55.89 μg kg^-1). Ciprofloxacin (2.94 to 4.18 μg kg^-1) was the sole CEC detected in biota samples. The ecotoxicological risk assessment indicated that the concentrations of all detected compounds posed significant ecotoxicity risks to the aquatic environment. In particular, caffeine and diclofenac presented considerable acute and chronic toxic risks to aquatic organisms, including algae, crustaceans, and fish. The Hazard Index (HI) values (3.65^-7 to 8.06^-8) suggest that ingesting ciprofloxacin at the concentrations found in fish does not represent a significant risk to human health. However, due to the reported risks to estuarine biota, it is crucial to continuously monitor the accumulation of these compounds in food widely consumed by the local population to assess potential impacts on human health.