Selectivity Enhancement for Petroleum Hydrocarbons Using a Smectic Liquid Crystalline Stationary Phase in Supercritical Fluid Chromatography

1 June 1988

journal article
Published by Oxford University Press (OUP) in Journal of Chromatographic Science

Vol. 26 (6) , 280-289
https://doi.org/10.1093/chromsci/26.6.280

Abstract

A liquid crystalline polysiloxane is successfully used as a stationary phase in capillary supercritical fluid chromatography (SFC). It is found that the resolution of polycyclic aromatic compounds (PACs) is greater in SFC than in gas chromatography (GC) using the same phase because of the more ordered structure of the phase at the relatively low SFC operating temperatures. Also, the PACs are selectively retained over alkanes, affording excellent hydrocarbon group-type separation. The separations on this phase of high-molecular-weight PACs (MW⩾320) in SFC are compared to separations on a nonpolar methyl polysiloxane phase. Results show that the liquid crystalline stationary phase is superior for resolving these PAC isomers. In addition, it is found that the molecular shape selectivity of the liquid crystalline phase is enhanced by applying higher supercritical fluid pressures. The contributing factors to the observed retention of PACs in SFC using the liquid crystalline stationary phase are discussed.

Keywords

This publication has 0 references indexed in Scilit: