Capillary electrophoretic analysis of cyclodextrins with dynamic fluorescence labeling and detection

Abstract

The use of 8-anilinonaphthalene-1-sulfonic acid (8,1-ANS) as buffer additive in the capillary electrophoretic separation of cyclodextrins (CDs) was investigated. Better detection sensitivity was obtained for α- and γ- CDs than with previously reported capillary electrophoretic methods. Increasing the concentration of 8, 1-ANS improved resolution and sensitivities for α-, β- and γ-CDs, while decreasing the pH of the background electrolyte can improve sensitivities. Detection limits for α-, β- and γ-CDs were determined to be 60, 20 and 7 μM, respectively. The formation constants of CD-8,1-ANS complexes at pH 6 were also measured by capillary electrophoresis. Finally the specificity of amyloglucosidase to CDs was analyzed as a practical application of this method.