Alkyl glucamine-based mixed-mode stationary phase for reversed-phase and hydrophilic interaction liquid chromatography

In modern liquid chromatography, versatile mixed-mode stationary phases have emerged as a practical choice for complex separations. Glucamine is promising in this field due to its distinctive amino-substituted glucose structure. This work presents a novel alkyl glucamine-based stationary phase (SIL–GNOGA) prepared via an epoxide-amine ring-opening reaction and immobilized onto silica surfaces. The morphology and composition of the stationary phase were characterized by multiple analytical techniques. Its retention mechanism was systematically investigated using analytes with diverse properties under varied chromatographic conditions. Furthermore, the separation performance of SIL–GNOGA was assessed and compared against its alkylamine- and glucamine-based counterparts. The stationary phase demonstrated excellent versatility, enabling efficient separation of hydrophilic, hydrophobic, as well as amphiphilic analytes in hydrophilic interaction or reversed-phase mode, depending on their molecular characteristics. Notably, complex mixtures were successfully resolved in both modes through the synergistic effects of hydrophilic, hydrophobic, hydrogen-bonding, and electrostatic interactions. This mixed-mode capability highlights SIL–GNOGA’s broad selectivity and potential across diverse chromatographic applications.