Spectrophotometric Determination of Glucosamine and Its Analogous Amino Sugars with o-Hydroxyhydroquinonephthalein and Palladium(II)

A simple and highly sensitive spectrophotometric method for the determination of glucosamine and its analogous amino sugars was established based on fading of the palladium(II)-o-hydroxyhydroquinonephthaleinhexadecyltrimethylammonium complex. In the determination of glucosamine, Beer’s law is obeyed in the range of 0.02 - 0.18 µg ml-1, with an effective molar absorptivity at 630 nm and the relative standard deviation being 8.4 × 105 dm3 mol-1 cm-1 and 1.08% (n = 10). This method is about 70-times more sensitive than the Elson-Morgan method. The method was successfully applied to the assay of glucosamine in actual samples.