Determination of the composition of Chinese ligustrum lucidum polysaccharide by capillary zone electrophoresis with amperometric detection

In this paper, capillary zone electrophoresis with amperometric detection was firstly applied to indirectly determine the composition of Chinese ligustrum lucidum polysaccharide (LLPS) by analyzing its hydrolyzates: fucose, glucose, arabinose and rhamnose. Under the selected optimum conditions, the four monosaccharides could be perfectly separated within 30 min and showed significant current responses at the copper electrode. The linear ranges of fucose, glucose and arabinose were all from 5.0×10^-6 to 1.0×10^-4 mol l^-1 and that of rhamnose was from 1.0×10^-5 to 1.0×10^-4 mol l^-1, and their detection limits were lower or near 1.0×10^-6 mol l^-1 (S/N=3). Experiments showed that the mole ratio of fucose, glucose, arabinose and rhamnose in Chinese LLPS was 1.80:4.58:2.55:1.91, and the purity of this polysaccharide leached by the introduced leaching method was 93.3%. Analyzing polysaccharide by this method has some merits of quickness, low-volume sampling, simple instrument, high sensitivity and high reproducibility.