[Preparation of nanopaticles of SCF-CO2 extraction of Magnolia officinalis].

OBJECTIVE

To prepare nano-particles of SCF-CO2 extraction of Magnolia officinalis with rapid expansion of supercritical solution (RESS) and optimize the preparation procedure with orthogonal experiment.

METHOD

The preparation procedures were optimized by orthogonal test L9(3(4)) with the mean particle size and the amounts of total-phenol as indexes. Factors of the extraction pressure and temperature, diameter of nozzle, pre-expansion temperature were evaluated for their effects on preparation process.

RESULT

The optimal preparation technology was as follows: the pressure was at 25 MPa and temperature was at 50 degrees C, the diameter of nozzle was 200 microm, the pre-expansion temperature was at 30 degrees C. The nano-particles solution was settled, of which the average particle size was 303.50 nm and the total-phenol contents was 0.091 g x L(-1), and the stability of the particle size kept well after 1 month of storage at low temperature and obturation the mean particle size.

CONCLUSION

The RESS method is applicable for preparing nanoparticles solution of SCF-CO2 extraction of M. officinalis at low operating temperature. It is simple processing, and no environmental pollution, and no residual solvent.