SEPARATION OF SUGAR ANOMERS BY CAPILLARY  ELECTROCHROMATOGRAPHY

Marjan Guček, Boris Pihlar
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5,
SI-1000 Ljubljana, Slovenia

ABSTRACT

Capillary electrochromatography (CEC) as one of the most efficient separation techniques has been successfully applied to carbohydrate analysis. CEC columns are pressure-packed with an octadecyl silica stationary phase and exhibit a linear velocity of electroosmotic flow up to 1.25 mms-1 and separation efficiencies up to 220 000 plates/metre for thiourea.
PMP-derivatives of sugars are successfully separated with large separation efficiencies (up to 600 000 plates/metre for PMP-mannose). This study shows that it is possible to separate the anomers of some sugars, PMP-glucose, galactose and lactose, based on their complexation with borate. The optimal eluent consists of 15 mM boric acid in 75% MeCN, 25% water (v/v). The anomeric separation of PMP-mannose is not possible even at elevated concentrations of boric acid.