ECOTOXICITY OF EAN AND DOPED EAN IONIC LIQUIDS

The ecotoxicity of a nitrate-based Ionic Liquid (IL) and saturated mixtures with four nitrate salts was tested in this work, towards the bioluminescent bacteria Vibrio fischeri, using the Microtox^® standard toxicity test [1]. 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 [2].

Results of EC₅₀ for pure EAN at 15 minutes are in relatively good concordance with Montalbán et al. [3]. 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 on the ecotoxicity of EAN, specially for the IL doped with Al(NO₃)₃ which present values associated to highly toxic compounds, even comparable with benzene or atrazine [2].