Abstract
A novel “one‐pot” strategy was developed for the preparation of amino acid (AA)–silica hybrid monolithic column. The basic AA (L‐Arginine, L‐Lysine and L‐Histidine) was covalently incorporated into the silica hybrid skeleton via the epoxy ring‐opening reaction between the amine group and the glycidyl moiety in γ‐glycidoxypropyltrimethoxysilane (GPTMS), which was confirmed by elemental analysis and FT‐IR studies, while the basic AA was also found to catalyze the polycondensation of tetramethoxysilane and GPTMS. The average mesopore and macropore sizes of the prepared basic AA–silica hybrid monolithic columns were 3.86 nm and 1.71 μm for the L‐Lysine–silica hybrid monolith, 5.38 nm and 4.24 μm for the L‐Arginine–silica hybrid monolith, and 6.38 nm and 1.24 μm for the L‐Histidine–silica hybrid monolith. The hybrid monolith afforded a zwitterionic stationary phase for CEC, the direction and magnitude of EOF can be controlled by the pH of the mobile phase used. Besides an electrophoretic mechanism, the monoliths behave in a typical hydrophilic interaction with the analytes when ACN percentage in the mobile phase is over 40%. Four polar compounds (toluene, DMF, formamide and thiourea) were tested on the three AA–silica hybrid monolithic columns, and the best separation efficiency was observed in the L‐Lysine–silica hybrid monolithic column, its theoretical plate height was down to 5.7 μm for thiourea when 20 mM HCOOH‐HCOONH~4~ containing 20% ACN (pH 4.1) was used as a running buffer. The corresponding theoretical plate number for toluene, DMF, formamide and thiourea were 123 385, 103 620, 121 845 and 105 345 plates/m, respectively. Effective separation of phenols and peptides on the L‐Lysine–silica hybrid monolithic column was achieved using CEC. We believe that this strategy paves a way for the easy preparation of various functional silica hybrid monolithic columns, aiming at different separation purposes.