Cytotoxicity of ionic liquids and precursor compounds towards human cell line HeLa

The toxicity of ethyl-, butyl-, octyl-, benzyl-, and allyl-substituted 1-alkyl-3-methylimidazolium, alkylpyridinium, N-alkyl-N, N-dimethyl-N-(2-hydroxyethyl) ammonium (choline derivatives) and alkyl-triethylammonium salts towards HeLa cells has been studied. The relative toxicities have been determined in the presence and absence of foetal bovine serum using an MTT assay after 24 and 48 h, and attempts to determine possible sources of the observed toxicity investigated using microscopy and by measuring the intracellular calcium concentration, presence of reactive oxygen species and mitochondrial membrane potential in cells exposed to 1-ethyl-3-methylimidazolium tetrafluoroborate.