ACUTE TOXICITY OF SELECTED IMIDAZOLIUM IONIC LIQUIDS TO Scenedesmus obliquus AND QSAR STUDY

Ionic liquids have hazard potential to humans and the environment. Acute toxicity of 10 imidazolium ionic liquids was studied by using Scenedesmus obliquus as indicator organism. The effective concentrations (EC50) of these ionic liquids at 96 h were determined, respectively, and quantitative structure-activity relationships (QSAR) were also examined. Experimental results indicated that the toxicity of these ionic liquids to Scenedesmus obliquus is different, which is induced from the different head groups, functionalized side chains and anions. The toxicity of these ionic liquids increases with the increase of the length of functionalized side chains, and does not change obviously when the cations are kept the same. QSAR analysis indicated that the acute toxicity relates to the molecular weight. The toxicity of imidazolium ionic liquids has the trend to increase with the increase of energy of the highest occupied molecular orbital (EHOMO), but to decrease with the increase of the largest positive atomic charge on a hydrogen atom (qH(+)).