Abstract: A method for the separation of six monosaccharides was established by using high performance liquid chromatography (HPLC) with 1-phenyl-3-methyl-5-pyrazolone (PMP) pre-column derivatization. This method was applied to analyze the monosaccharide composition of polysaccharides isolated from 10 fruit samples of Lycium barbarum L. collected from different growing areas and 8 commercial samples obtained from different companies. With the merits of simplicity, high sensitivity and good repeatability, the HPLC method was suitable for the monosaccharide composition analysis and quality control of L. barbarum polysaccharides. Results showed that polysaccharides isolated in our laboratory were composed of mannose, rhamnose, galactose acid, glucose, galactose and arabinose at an average molar ratio of 1.00:1.38:0.63:92.37:1.18:3.55. Polysaccharide contents were determined to be within the normal range for 6 of the 8 commercial samples, while the remaining ones exceed the average. The commercial samples contained 2?3 times more glucose (in mole) than the laboratory prepared samples.

Key words: Lycium barbarum L., polysaccharide, monosaccharide composition, pre-column derivatization, HPLC