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

Abstract

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.