The invention provides a method for separating and purifying
rebaudioside C. The method includes steps of a), mixing
stevioside mother liquor sugar and water with each other, preparing
mother liquor sugar solution, loading samples by the aid of pumps, allowing the samples to flow through chromatographic columns filled with fillers, carrying out
elution by the aid of
methanol aqueous solution, detecting and collecting
rebaudioside C components by means of HPLC (high-performance liquid
chromatography), concentrating the
rebaudioside C components by the aid of nano-
filtration membranes and dryingthe rebaudioside C components to obtain rebaudioside C component dried substances; b), dissolving the rebaudioside C component dried substances, which are obtained at the step a), by the aid of ethylalcohol-
acetone-water, carrying out primary
crystallization and further carrying out filtering and
drying to obtain primarily crystallized crystals; c), dissolving the primarily crystallized crystals, which are obtained at the step b), by the aid of ethyl
alcohol-
methanol-water, carrying out secondary
crystallization, and further carrying out still standing, filtering and
drying to obtain rebaudioside C finished products.
Silica gel is used as a matrix for the fillers, and octadecyl
silane and
divinyl benzene are bonded on the
silica gel. The method has the advantages that the high-purity rebaudioside C can be prepared by the aid of the method, and the method is high in yield;
rebaudioside A can be recycled, the fillers are long in service life, and solvents are easy to recycle.