Study of the toxicity of five quaternary ammonium ionic liquids to aquatic organisms

摘要

The study aimed to test the toxicity of five quaternary ammonium ionic liquids with varying numbers (from one to three) of didecyldimethylammonium cations and single nitrite, nitrate, or citrate anions toward Vibrio fischeri (5- and 15-min acute luminescence inhibition), Daphnia magna (24- and 48-h acute immobilization test), Artemia salina (24-h acute immobilization test), Pseudokirchneriella subcapitata (72-h chronic growth inhibition test), and Lemna minor (7-d chronic growth inhibition test). Subsequently, the activities of catalase, superoxide dismutase, and glutathione S-transferase were measured in D. magna and L. minor after treatment with 25% and 50% effective concentrations of the most toxic compound. The results clearly indicate that the toxicity depends on the number of cations in the molecule: the more cations there are, the higher the toxicity. The toxic effects at 50% calculated in this study ranged between 0.01 and 100 mu M depending on the test organism. Of all the test species, D. magna was the most and A. salina the least sensitive to the tested compounds. The most toxic ionic liquid inhibited catalase and increased superoxide dismutase activity in both organisms. Oxidative stress is either directly or indirectly involved in the toxic mechanism of the tested ionic liquid action.