Characterization of Cyclodextrin Derivatives by the Reductive-Cleavage Method

Abstract

Structure and uniformity of alkylated cyclodextrins have been investigated by the reductive-cleavage method, introduced by Gray and coworkers (1). The glucosidic bonds of the cyclodextrins were cleaved by action of a Lewis acid and reduced by triethylsilane to the corresponding anhydroglucitols. The degradation products were identified by combined gas chromatography/mass spectrometry (g.c./m.s.) using both chemical and electron impact ionization methods.

Quantification was carried out by g.c.. The peak areas were corrected for their different molar responses in the flame ionization detector applying the effective-carbon-response (e.c.r.) -concept (2,3). By this analysis the substitution pattern of all anhydroglucose units could be determined and over- or underalkylation could be recognized up to 0,1% anhydroglucose unit (AGU). Only small amounts of sample — ~ 0,5 mg — are necessary.