Limiting Partition Coefficients of Sulfur-Containing Aromatics in a Biphasic [bmim][MeSO4]−Supercritical CO2 System

Infinite dilution (limiting) partition coefficients of several sulfur-containing aromatics (benzo[b]thiophene, benzothiazole, dibenzothiophene, 4,6-dimethyldibenzothiophene, phenoxathiin, and thianthrene) in a biphasic (1-n-butyl-3-methylimidazolium methyl sulfate ([bmim][MeSO4]) + carbon dioxide) system were measured at temperatures of (313 to 353) K and pressures of (8.5 to 23.2) MPa. The measurement method was capillary column supercritical fluid chromatography (SFC) with [bmim][MeSO4] serving as the stationary liquid and supercritical CO2 as the carrier fluid. Partition coefficients of sulfur-containing aromatics are discussed as functions of temperature and CO2 density. In addition, other solute partition coefficient data obtained from previous SFC measurements in the systems with ionic liquids [bmim][PF6], [bmim][BF4], [bmim][MeSO4], [hmim][Tf2N], and [thtdp][Cl] are reported in the Supporting Information.