3.1. Glucosamine separation and quantitative determination
Chitosan and a formulation containing chitosan were hydrolyzed, derivatized, and analyzed with HPLC. The chromatograms for the hydro lysates were the same as those for glucosamine standards. As shown in the chromatogram (Fig. 2), glucosamine derivatives were detected in two peaks at 6 and 7.5 min. This is due to the presence of two possible conformations of free glucosamine (α- and β-glucosamine) in solution (Zhouet al., 2005). The sum of the two peak areas was used to calculate total glucosamine content.