A stationary phase bearing both bridged bis-ureido and free amino groups has been prepared starting from 2.5 µm porous silica particles. Kinetic performances of columns packed with the stationary phase have been evaluated in near-UHPLC hydrophilic interaction liquid chromatography using complex mixture of sugars as high polar test compounds. In hydrophilic interaction chromatography, retention of polar solutes is obtained using a polar stationary phase and an aqueous organic mobile phase with water acting as the stronger eluent.
In the lower part of the cover picture, the stationary phase is shown as a grey and white layer carrying polar groups as surface active functionalities. The use of reduced particle sizemoves the phase applicability in near-UHPLC regime offering high efficiencies. This is illustrated in the upper part, where the black chromatographic profile of beer components is overlaid on the blue water-rich layer, with the ball and stick maltose oligomers flowing free with the clear mobile phase.