TEMPERATURE AND PRESSURE EFFECTS ON SOLUBILITY IN SUPERCRITICAL CARBON-DIOXIDE AND RETENTION IN SUPERCRITICAL-FLUID CHROMATOGRAPHY

Solubilities of some polycyclic aromatic hydrocarbons (PAHs) in superc ritical carbon dioxide were measured with a procedure based on a direc t on-line combination of a saturation cell to a flame ionization detec tor. Acenaphthene, anthrance and chrysene were selected as the test so lutes. A method was developed and evaluated which enables the measurem ent of the contribution of solute vapor pressure to the overall solubi lity. The effects of temperature and pressure on solubility in supercr itical carbon dioxide were investigated and discussed in detail. The t rends of solubility changes in supercritical carbon dioxide and the va riations in observed retention in supercritical fluid chromatography ( SFC) were correlated. Equations were derived to estimate the effects o f temperature on the solute's affinity for the stationary phase in SFC . (C) 1997 Elsevier Science B.V.