METHODS With the transferring rate as index, the optimum extraction condition for the alcohol concentration, the volume, extra ting time and times were selected by orthogonal design.

Osmotic force is the tendency of a solvent to equalize concentration throughout its volume. This force is overcome by applying pressure to the paint passing through the ultrafilter.

Use a conical flask to fix the volume, addition of a working solution of known concentration by several times can prepare a standard series.