High-performance anion-exchange chromatography of homogeneous d-gluco-oligosaccharides and -polysaccharides (polymerization degree ⩾ 50) with pulsed amperometric detection

Abstract

High-performance anion-exchange chromatography under alkaline conditions with pulsed amperometric detection was applied to the analyses of (1 → 2)-, (1 → 3)-, (1 → 4)- and (1 → 6)-linked homogeneous α- or β- d-gluco-oligosaccharides and -polysaccharides up to a degree of polymerization (DP) of ⩾ 50. Each series of homogeneous d-gluco-oligomers and -polymers showed a linear relationship between log k′ and DP in isocratic elution using 150 m M sodium hydroxide solution containing 100 m M sodium acetate as the eluent. An effective separation of individual members of an homologous series of linear glucans was achieved using gradient elution, accomplished by maintaining the sodium hydroxide concentration at 150 m M and increasing the sodium acetate concentration during the analysis. The detector response per HCOH group in d-gluco-oligomers (DP 2–7) was almost the same.