Development of a C60-fullerene bonded open-tubular capillary using a photo/thermal active agent for liquid chromatographic separations by π–π interactions

This short communication describes a newly developed open-tubular capillary which was coated with C60-fullerene by a covalent bonding via a photo/thermal active agent. We utilized perfluorophenyl azide (PFPA) as an active agent, which can be used for the “photo click” coupling of the carbon materials. The inner wall of a fused silica capillary was treated with silane conjugated PFPA, and then C60-fullerene was chemically modified by a photoreaction or a thermal reaction. Through evaluations of the capillaries by liquid chromatography, the separation characteristics of three polycyclic aromatic hydrocarbons (PAHs) were confirmed in both capillaries. With comparison of the retention behavior to a commonly used C18 column, the prepared capillaries showed the specific separation ability based on the π–π stacking by C60-fullerene. The capillary prepared by the thermal reaction provided the base line separation of phenanthrene, triphenylene, and benz[a]pyrene within 3 min at 18.8 cm capillary length.