Abstract
In the present work, an experimental study is presented aimed at assessing the chronic toxicity of three imidazole-based ionic liquids, i.e. imidazole (IM), 1-methylimidazole (1MIM), 1-ethyl-3-methyl-imidazolium chloride (1E3MIM), and 1-butyl-3-methyl-imidazolium chloride (1B3MIM), generally considered as environmentally friendly surrogates of traditional industrial solvents. In this study Daphnia magna was used as test organism due to its wide application in the ecotoxicological literature of ionic liquids, monitoring both the cumulative survival of exposed organisms, and their reproductive parameters. The intracellular oxidative stress of daphnids was also assessed through the determination of Reactive Oxygen Species (ROS) and Catalase activity (CAT). The chronic toxicity of their oxidized by-products (BPs), generated by advanced oxidation treatment with UV254/H2O2, was finally evaluated. Four generations of BPs were considered, each formed at reaction times higher than those required for the complete removal of the parent compounds. Results indicate that IM and 1MIM have a moderate chronic toxicity, which mainly affects reproductive parameters. On the contrary, 1E3MIM and 1B3MIM showed significantly higher chronic toxicity effects resulting in a significant increase in the mortality of exposed organisms compared to the controls. UV/H2O2 treatment of the compounds did not always reduce the observed effects, since the generated BPs have, in some cases, higher chronic toxicity than their corresponding parent compounds. Chronic toxic effects remained significant up to the fourth generation of BPs in the cases of 1E3MIM and 1B3MIM, whereas they were found to be negligible from the second generation of BPs in the case of IM and 1MIM. The results of oxidative stress measurements confirmed the previous findings, suggesting a potential risk for the aquatic ecosystem induced by the mentioned compounds and their BPs.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
