Preparation and chromatographic evaluation of a novel phosphate ester-bonded stationary phase with complexation and hydrophobic interactions retention mechanism

The present study described the preparation of a novel phosphate ester-bonded silica (PES) stationary phase based on "thiol-ene" click chemistry. The composition of the surface grafts of PES stationary phase was determined by elemental analysis and solid state (31)P MAS NMR. Due to its hydrophilic phosphate-ester groups and short hydrophobic alkyl chains, the PES stationary phase exhibited dual retention mechanism via complexation and hydrophobic interactions with phenols. Benefiting from this special interaction mechanism, the newly synthesized PES stationary phase showed better selectivity in the separation of phenols compared to commercial octadecylsilyl-bonded silica (C18) columns. Furthermore, the separations of 10 nucleosides and nucleobases on the PES stationary phase were achieved in both reversed-phase liquid chromatography (RPLC) mode and hydrophilic interaction liquid chromatography (HILIC) mode.