HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC SEPARATION OF OLIGOGALACTURONIC ACIDS ON A CYCLOMALTOHEPTAOSE (BETA-CYCLODEXTRIN) BONDED-PHASE COLUMN

A cyclomaltoheptaose (beta-cyclodextrin) bonded-phase HPLC column was used for the first time to separate acidic oligosaccharides. Oligogala cturonic acids up to a degree of polymerization (dp) of 7 were separat ed with a 50:50 acetonitrile-sodium phosphate-buffered (pH 5) mobile p hase and up to dp 17 with an isocratic pH 5.0, sodium phosphate-buffer ed mobile phase. A sodium acetate gradient elution allowed for improve d resolution of all oligogalacturonic acids, up to a dp value of at le ast 24. Although the stationary phase contained no cationic or readily ionizable groups, these separations appeared to be governed by a clas sical anion exchange-type mechanism. The beta-cyclodextrin-bonded phas e, which displayed exceptional stability over one year of use, is a us eful alternative to silica gel- or organic polymer-based anion exchang ers for HPLC of acidic carbohydrates.