Recently, mixed-mode chromatography has been shown to be a flexible and versatile method for the simultaneous separation of highly mixed classes of analytes, especially ions and organic compounds. In principle, the mixed-mode stationary phases were designed by combining two or more separation mechanisms such as non-specific hydrophobic interactions and specific electrostatic interactions. The resulting materials often tend to offer quite different selectivity from conventional ODS columns where the separation and selectivity are dominated largely by hydrophobic interactions. Imidazolium, an unique aromatic heterocyclic cation, has been used as a mixed-mode chromatographic stationary phase with selectivity enhancement and tunability. In this paper, we prepared a new ionic liquid stationary phase (SilBim-C8) containing aromatic and fatty group , which was synthesized with benzimidazole and C8 group. Mechanism involved in the chromatographic separation is the multi-interaction including hydrophobic, π-π, hydrogen-bonding, inclusion and anion-exchange interactions. Based on these interactions, successful separations could be achieved for polycyclic aromatic hydrocarbons, aromatic position isomers, organic bases and phenols in reversed-phase chromatography. Inorganic anions were also shown to be individually separated in anion-exchange chromatography by using the same column. Such stationary phase with characteristics of multi-interaction mechanism and mixed-mode separation is potential for the analysis of complex samples.
　　
The authors acknowledge the support of NSF of China (21275133)