Capillary electrophoretic profiling of wood-based oligosaccharides

Abstract

A method based on direct UV-detection was developed for the qualitative and quantitative determination of oligosaccharides simultaneously separated by capillary electrophoresis (CE). Reference compounds consisting of five xylo- three manno- and five cello-oligosaccharides were concurrently measured in a highly alkaline solution without derivatization. Sodium and potassium cations were used in the electrolyte solution to adjust the electrokinetic properties of the oligomers by controlling the mobility of charged species and to improve the resolution in baseline separation. The quantification range extended from 25 to 125 mg/L with linear correlation \(\hbox {R}^{2}=0.986{-}0.997\) for all analytes other than xylobiose and cellobiose, for which the range was 50–200 mg/L (\(\hbox {R}^{2}=0.995\)). The CE method developed was further applied to determine oligosaccharides from hot-water extracts of a bleached birch and pine kraft pulp, in which the oligosaccharides typically exist as complex mixtures.