Binary and quaternary solubility of 2-ethyl-hexyl-2-ethyl hexanoate (2E2E) in supercritical carbon dioxide have been measured at flow rate of 250 +/- 10 ml/min, and (a) constant temperature of 313 K in the pressure range of 90-253 bar, (b) constant pressure of 170 bar, in the temperature range of 313-353 K, and (c) constant temperature of 313 K and pressure of 170 bar in flow rate range of 100-300 ml/min. The quaternary solubilities of 2-ethyl-1-hexanol and 2-ethyl hexanoic acid in supercritical carbon dioxide (SC-CO2) were found to be greater than of 2E2E at pressure of 170 bar, a temperature of 313 K, and a flow rate of 250 +/- 10 ml/min. There is an isosolubility range for the mixed-liquid of the acid and the ester. Solubility diminutions (similar to69-75%) of 2E2E at different pressures were observed for the quaternary model system compared to the binary system in SC-CO2. (C) 2002 Elsevier Science B.V. All rights reserved.