KCS

Size Exclusion Chromatography has been extensively used to monitor molecular weight distribution of polymer samples. Application of SEC for oligosaccharides is widespread, too. However, complete separation of individual oligosaccharides composed of even single monosaccharide by SEC is not possible yet. In this study, a simple method has been developed for determination of molecular weight distribution and average molecular weights. The sample was modified by reductive amination with 4-aminobenzoic acid ethyl ester (ABEE), and ABEE-oligosaccharides were separated in a HPLC system with a common C18 column and a mobile phase of high water content. Baseline separation was observed for ABEE-oligosaccharides. In this system, a larger solute elutes faster than a smaller solute. The merit of this method is the fact that standards are not required since the signal intensity of each ABEE-oligosaccharide is generally proportional to its molar concentration regardless of its molecular weight. The applicability of this method has been examined for a synthetic, a dextran sample, and beer samples.