Determination of glucosamine in nutritional supplements by reversed-phase ion-pairing HPLC

A reverse-phase high performance liquid chromatography (HPLC) method for the determination of glucosamine in nutritional supplements was developed and validated based on USP guidelines. Separations were performed using a MetaChem Inertsil ODS-3 column with an isocratic mobile phase consisting of 10% Methanol, 90% 0.005M octanesulfonate, pH = 2.1. Glucosamine was detected using a refractive index (RI) detector. The octanesulfonate ion pairing agent allowed for retention on a C-18 column. The method proved highly reliable with respect to standard performance characteristics. The method allows for convenient quality control in the growing nutritional supplement market.