A SPE-HPLC-MS/MS method for the simultaneous determination of pr ior itised pharmaceuticals and EDCs with high environmental risk potential in freshwater

This work describes the development,optimisation and validation of an analytical method for the rapid determination of 17 priority pharmaceutical compounds and endocrine disrupting chemicals(EDCs).Rather than studying compounds from the same therapeutic class,the analyses aimed to determine target compounds with the highest risk potential(with particular regard to Scotland),providing a tool for further monitoring in different water matrices.Prioritisation was based on a systematic environmental risk assessment approach,using consumption data;wastewater treatment removal efficiency;environmental occurrence;toxicological effects;and pre-existing regulatory indicators.This process highlighted 17 compounds across various therapeutic classes,which were then quantified,at environmentally relevant concentrations,by a single analytical methodology.Analytical determination was achieved using a single-step solid phase extraction(SPE)procedure followed by high-performance liquid chromatography with tandem mass spectrometry(HPLC-MS/MS).The fully optimised method performed well for the majority of target compounds,with recoveries>71%for 15 of 17 analytes.The limits of quantification for most target analytes(14 of 17)ranged from 0.07 ng/L to 1.88 ng/L in river waters.The utility of this method was then demonstrated using real water samples associated with a rural hospital/setting.Eight compounds were targeted and detected,with the highest levels found for the analgesic,paracetamol(at up to 105,910 ng/L in the hospital discharge).This method offers a robust tool to monitor high priority pharmaceutical and EDC levels in various aqueous sample matrices.

Mercury in alpine fish from four rivers in the Tibetan Plateau

As a global pollutant, high levels of mercury（Hg） have been found in remote ecosystem due to the long range atmospheric transport. In this study, a total of 60 fish samples were collected from four rivers across the Tibetan Plateau to study the accumulation of Hg in remote and high-altitude aquatic environment. The total Hg（THg） and methylmercury（MeHg） in fish muscles ranged from 11 to 2097 ng/g dry weight（dw）（average： 819 ng/g dw）and from 14 to 1960 ng/g dw（average： 756 ng/g dw）, respectively. Significantly positive linear relationships were observed between the THg（r = 0.591, p 〈 0.01, n = 36） and MeHg concentrations（r = 0.473, p 〈 0.01, n = 36） with the trophic level of fish from Lhasa River,suggesting trophic transfer and biomagnification of Hg in this aquatic ecosystem. Moreover,the THg levels in fish had significantly positive correlations with the length（r = 0.316,p 〈 0.05, n = 60） and weight（r = 0.271, p 〈 0.05, n = 60） of fish. The high levels of Hg were attributed to the slow growth and long lifespan of the fish under this sterile and cold environment. Risk assessment revealed that the consumption of Oxygymnocypris stewartii,Schizothorax macropogon, Schizothorax waltoni, Schizopygopsis younghusbandi and Schizothorax o＇connori would lead to a high exposure to Me Hg.