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 3min at 18.8cm capillary length.