The ecotoxicity of a nitrate-based ionic liquid (IL) and saturated mixtures with four nitrate salts towards the bioluminescent bacteria Vibrio fischeri, were tested in this work, using the Microtox® standard toxicity test. The selected IL was Ethylammonium Nitrate (EAN) and the nitrate salts were Lithium Nitrate (LiNO3), Calcium Nitrate (Ca(NO3)2), Magnesium Nitrate (Mg(NO3)2), and Aluminum Nitrate (Al(NO3)3). The effective concentration (EC50) of these mixtures was determined over three standard periods of time, namely 5, 15, and 30 min. Results of EC50 for pure EAN at 15 min are in relatively good concordance with the literature. To the best of our knowledge, no ecotoxicity studies have been performed for doped EAN. Similar results have been found for pure EAN and for EAN doped with LiNO3 and Mg(NO3)2, whose values indicated low toxicity. Nevertheless, the addition of Ca(NO3)2 and Al(NO3)3 cause an increase in the ecotoxicity of EAN, especially for the IL doped with Al(NO3)3, which present values associated to highly toxic compounds, comparable even with benzene or atrazine.
Unusual ion transport behaviour of ethylammonium nitrate mixed with lithium nitrate
