An interface has been developed that enables the direct coupling of a continuously stirred high pressure vessel with on-line supercritical fluid chromatography (SFC). The system provides a rapid means to determine the solubility of organic compounds in supercritical fluid carbon dioxide (SF-CO2). The method involves increasing the loaded vessel pressure in controlled steps to produce a series of progressively more saturated sample solutions for on-line SFC solubility measurements. The method was validated by obtaining mole fraction solubility data for caffeine in SF-CO2 at four different temperatures ranging from 313 K to 343 K through the pressure range 10-28 MPa. For caffeine, SFC detection was performed at 254 nm. The solubility of monensin in SF-CO2 was determined using SFC with post-column derivatization. Vanillin served as derivatizing agent with SFC detection at 520 nm. Mole fraction solubility data for monensin was obtained at 313 K and 328 K through the pressure range 10-27.5 MPa. (C) 2016 Elsevier B.V. All rights reserved.