Discriminant and simultaneous HPLC analysis of reducing and nonreducing monosaccharides on a polyethyleneimine-attached hydrophilic interaction liquid chromatography column

The aim of this study was to develop an analytical method for the discrimination of reducing and non-reducing monosaccharides including rare sugars on a prototype hydrophilic interaction liquid chromatography (HILIC) column. The HILIC column was composed of a glycidyl methacrylate-ethylene glycol dimethacrylate copolymer attached to 8 wt% polyethyleneimine. Seven monosaccharides (reducing aldoses: D-xylose, D-allose, and D-glucose; non-reducing ketoses: D-fructose, D-psicose, D-sorbose, and D-tagatose) were targeted. In individual HPLC analysis of both aldoses and ketoses, elution with 90 v/v% acetonitrile permitted successful detection and separation only for the non-reducing ketoses. Besides, elution of a mixture of ketoses and aldoses with 85 v/v% acetonitrile containing 5 mmol/L sodium 1-octanesulfonate (OS) (pH 4.8) enabled the simultaneous separation of all seven monosaccharides within 40 min. The polyethyleneimine-attached HILIC column allowed discriminant HPLC analysis for non-reducing ketoses using elution with 90 v/v% acetonitrile, whereas elution with 85 v/v% acetonitrile containing 5 mmol/L OS simultaneously detected both ketoses and aldoses.