C₆₀-Fullerene Bonded Silica Monolithic Capillary for Specific Separations of Aromatic Compounds

Abstract

A simple preparation method for C₆₀-fullerene bonded silica monolithic capillary by thermal coupling with a specific agent is reported. A silica monolithic capillary was modified with aminopropyl silane by a typical modification method, and then a thermal coupling agent, perfluorophenyl azide (PFPA) was covalently reacted with the amino groups. After C₆₀-fullerene was covered over the PFPA-monolith at high density, thermal reaction was carried out at 170 C for 5 h, resulting C₆₀-fullerene bonded silica monolith. We qualitatively confirmed all the modification process by elemental analysis and FT-IR, which showed the accomplishment of the all the reactions. According to liquid chromatographic evaluations, C₆₀-fullerene bonded silica monolithic capillary provided the specific separation of polycyclic aromatic hydrocarbons (PAHs) by an effective π−πinteraction based on the bonded C₆₀-fullerene. Even if we used non-polar solvent, n-hexane, as a mobile phase, the effective base-line separation of PAHs was achieved. Additionally, the capillary allowed the separation of aromatic couples, including benzene/anisole, dibenzosuberone/dibenzosuberenone, and chrysene/triphenylene, which have slightly structural differences, depending on the density of π electrons in these compounds.