MOLECULAR SHAPE-RECOGNITION OF POLYCYCLIC AROMATIC-HYDROCARBONS WITH A LIQUID-CRYSTAL BONDED PHASE IN SUPERCRITICAL FLUID CHROMATOGRAPHY

The chromatographic characteristics of a liquid crystal bonded phase have been evaluated for the separation of polycyclic aromatic hydrocarbons (PAHs), especially focusing on its shape recognition capability in supercritical fluid chromatography (SFC). The results clearly indicate that the phase has a stronger molecular planarity and shape recognition capability than typical polymeric and monomeric octadecylsilica (ODS) phases because of the very ordered bonded phase structure. The recognition capability was slightly dependent on SFC conditions such as column pressure, column temperature, and mobile phase density. Modifier addition did not make a large difference on the recognition capability. The phase seems to be a very promising stationary phase in SFC because the recognition capability is slightly influenced by the SFC conditions. Selectivity enhancement for molecular shape and planarity recognition has been found in SFC compared to reversed-phase LC separations with the same stationary phase.