Separation of Polycyclic Aromatic Hydrocarbons With Various C60 Fullerene Bonded Silica Phases in Microcolumn Liquid Chromatography

Abstract

Various chemically bonded C ₆₀ fullerene silica phases were synthesized as stationary phases for liquid chromatography (LC) and their retention behaviors were evaluated systematically with various polycyclic aromatic hydrocarbons (PAHs) using microcolumn LC. The results clearly indicate that the C ₆₀ bonded phases have a unique molecular recognition capability. With the C ₆₀ bonded phases, planar PAHs having a partial structure similar to that of the C ₆₀ molecule were retained longer than analogous PAHs molecules without the partial structure of C ₆₀ . The results also show that the C ₆₀ bonded phases with higher surface coverage (C-high type), i.e., 0.411 and 0.351 µmol m ^{- 2} , offered a selectivity different from that of the C ₆₀ fullerene bonded phases with lower surface coverage (C-low type), i.e., 0.102 and 0.159 µmol m ^{- 2} for the separation of isomeric PAHs. These retention behaviors can be explained by the fit of the molecular shape of the solute molecules to the stationary phase ligands. The separation of C ₆₀ and C ₇₀ fullerenes was also examined with various C ₆₀ bonded phases and the results showed that the separation factors were comparable to those with commercially available octadecylsilica (ODS) phases.