Comparison and modelling of rutin solubility in supercritical carbon dioxide and subcritical 1,1,1,2-tetrafluoroethane

- Solubilities of rutin in SCCO2 and subcritical R134a were determined.
- Extract rutin by SCCO2 or R134a above or below transition pressure, respectively.
- Solubility data were satisfactorily correlated by Chrastil and m-ER&HV model.
- Solubility data were tested to be thermodynamically consistent.

Rutin is a common dietary flavonoid that has been widely consumed in pharmaceutical industry. To facilitate the extraction of rutin from plant tissues, we determined the solubility of rutin in supercritical carbon dioxide by dynamic method at 313.2-343.2 K over the pressures range of 9.0-18.0 MPa and in subcritical 1,1,1,2-tetrafluoroethane (R134a) by static method at 313.2-343.2 K over the pressures rang of 7.0-18.0 MPa. The experimental results indicate that the extraction of rutin should be operated by subcritical R134a or supercritical CO2 below or above the transition pressure (the pressure at which the rutin solubilities in subcritical R134a and supercritical CO2 are the same), respectively. Furthermore, the solubility data were satisfactorily correlated by Chrastil model and m-ER&HV model (modified Esmaeilzadeh-Roshanfekr equation of state combined with Huron-Vidal mixing rule), and the thermodynamic consistency of the solubility data was confirmed by the thermodynamic consistency test.