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.