High-performance size-exclusion chromatography (HPSEC) of glycosaminoglycans

GAGs are produced by extraction and purification from different animal tissues. These preparations are composed of polysaccharide chains with broad structural heterogeneity and molecular size dispersion. The biological and pharmacological properties of natural polysaccharides as well as their derivatives are strictly related to their molecular mass and size distribution. As a consequence, a rapid, reliable and reproducible method to determine glycosaminoglycan molecular mass is necessary. High-performance size-exclusion chromatography (HPSEC) typically permits the determination of the number of average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity.HPSEC separation, and the number of average molecular weight (Mn), the weight average molecular weight (Mw), the Z average molecular weight (Mz) and the polydispersity index (Mw/Mn) were calculated for several natural polysaccharides purified from different tissues and sources, such as hyaluronic acid, a fructose-containing polysaccharide with a chondroitin backbone, various chondroitin sulfate samples, dermatan sulfate, heparan sulfate, heparin and its two components, slow moving and fast moving heparin. HPSEC was also used to evaluate the progress of a controlled chemical depolymerization process of chondroitin sulfate induced by free radicals in the presence of copper salt.