Objective: A method of 1-phenyl-3-methyl-5-pyrazolone (PMP) pre-column derivatization high performance liquid chromatographic was established for analysis of four kinds of monosaccharide and two kinds of galacturonic acid and glucouronic acid. Method: The polysaccharides were extracted by hot distilled water

precipitated by alcohol. The product was purified by ultrafiltration and formed monosaccharides by sulfuric acid hydrolysis. The hydrolysate reacted with PMP to produce the PMP derivatives that were analyzed by HPLC. The optimum conditions of derivatization were determined by studying the quantity of PMP and sodium hydroxide

reaction time

reaction temperature and hydrochloric acid consumption during neutralization. Under the optimum mobile phase which was acetonitrile-phosphate buffer (pH 6.8)

PMP derivatives can be separated successfully. This method was applied to monosaccharide compositions analysis of SDP

SDP-1

SDP-2

SDP-3. Result: The results showed that three polysaccharides (SDP-1

SDP-2

SDP-3) were obtained by ultrafiltration

molecular weights were less than 10

10-50 kDa and more than 50 kDa respectively. Both SDP and SDP-1 were composed of Man-GlcUA-GalUA-Glc-Gal-Ara in molar ratio of 1: 0.8: 0.7: 3.4: 3.3: 2.1 and 1: 0.5: 0.3: 0.6: 0.6: 0.4;SDP-2 was composed of Man-Glc-Gal-Ara in molar ratio of 1: 2.0: 0.2: 0.3;SDP-3 was composed of Man-Glc in molar ratio of 1: 5.4. Conclusion: The method is accurate and sensitive

thus suitable for the analysis of monosaccharide composition of Suanzaoren Decoction polysaccharide.