Room temperature ionic liquid (RTIL) 1-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) was employed as the stationary liquid in capillary column chromatography with supercritical carbon dioxide (scCO(2)) as the mobile phase. Open tubular capillary columns were used to measure the retention factors of anisole, azulene, benzil, alpha-ionone, naphthalene, pyrene, and veratrole within 313-353 K and 8.1-23.2 MPa. The retention factors were converted to infinite-dilution solute partition coefficients in the [bmim][PF6]scCO(2) system. Analysis of the relative retention data by regular solution theory resulted in approximate values of the solubility parameter of CO2-expanded [bmim][PF6]. Open tubular supercritical fluid chromatography appears to provide a viable method for rapid acquisition of partitioning data on low-volatility solutes in biphasic RTIL-scCO(2) systems.