Determination of cyclic glucans by anion-exchange chromatography with pulsed amperometric detection

Abstract

Anion-exchange chromatography with pulsed amperometric detection was applied to the determination of cyclodextrins ( CDs), branched CDs and cyclosophoraoses. These cyclic glucans with degree of polymerization 6–25 were well resolved in each series by using simple isocratic elution with 150 m M sodium hydroxide solution containing 140–200 m M sodium acetate. The separation mode was not only simple anion exchange, but also involved some hydrophobic interactions and, moreover, inclusion interactions also seemed to take part in the retention. The detector response per glucose unit of these cyclic glucans was almost the same, regardless of the molecular weight and linkage form. The limit of determination of the cyclic glucans was 5–10 pmol and the detection limit was 2.5–5 pmol with a signal-to-noise ratio of 3.