AbstractThe hydrophobicity of ionic liquids, an important physical property, is currently attracting attention of scientists particularly for chemical–biological interactions. In this report, the hydrophobicity of selected ionic liquid (only imidazolium based) cations has been investigated according to some methods: chromatographic analysis, statistical, and chemometric approach. As a consequence, the lipophilicity, which is one of the important factors in biological activity of analyzed compounds, can be established. For that purpose, butyl, octyl, octadecyl, mixed, alkylamide, and cholesterolic packings were chosen and applied to the analysis of eight most commonly used ionic liquid cations. The use of different experimental and theoretical methods allow the estimation of ionic liquids properties. In the present study, chemometric and statistical methods have also been used for the comparison of hydrophobic or hydrophilic character of analyzed compounds and also to estimate their biological activity.