Conductivity detection for molecular mass estimation of per-O-sulfonated glycosaminoglycans separated by high-performance size-exclusion chromatography

Chemically per-O-sulfonated polysaccharides, including glycosaminoglycans (GAGs) and hyaluronan oligosaccharides were analyzed using high-performance size-exclusion chromatography (HPSEC) with suppressed conductivity detection. The results were compared to those obtained by gel filtration HPLC using UV detection or fluorescence detection after the post-column reaction with 2-cyanoacetamide in strong alkaline solution. Analysis was performed on a TSKgel G3000SWXL HPSEC column in 5 mM boric acid (pH 7.0 adjusted by 10 mM NaOH). The use of conductivity detection, in the absence of any derivatization and under isocratic conditions gave a limit of detection in the picogram range. Preliminary studies suggest that this approach may be particularly useful in examining sulfonated polysaccharides and oligosaccharides having no UV chromophore, such as those prepared from O-sulfonated fucans and galactans isolated from algae.