The infinite dilution partition coefficients (Kinf) were measured using a packed column chromatographic technique. The partition coefficients of solutes naphthalene or benzene in the 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim+][PF6-]) + CO2 system were studied and showed correlation of the data with the Sanchez-Lacombe (SL) EOS that has widely been applied to polymer systems. The partition coefficients for naphthalene and benzene, respectively, differed by about 1 order in magnitude, with those Kinf of naphthalene being much lower than benzene. The trend of the partition coefficient predicted by the SL EOS was much like that of the solubility of a solid in a supercritical fluid and that of an involatile liquid in a supercritical fluid. The SL EOS provided accurate correlation of the trends and provided some ability to extrapolate the data with temperature or pressure. This is an abstract of paper presented at the AIChE Spring National Meeting (Orlando, FL 4/24-26/2006).