Development of a simple capillary electrophoretic determination of glucosamine in nutritional supplements using in-capillary derivatisation with o-phthalaldehyde

► Determination of glucosamine using in-capillary derivatisation. ► Electrophoretic solution containing o-phthalaldehyde and 3-mercaptopropionic acid. ► The detector response was linear (r2 > 0.999) in the concentration range 10-1000 μg/mL. ► The method was applied to 16 commercial products. ► The results were consistent with the finding of a colorimetric method.