A novel click lysine zwitterionic stationary phase for hydrophilic interaction liquid chromatography

A novel type of zwitterionic HILIC stationary phase was prepared by covalently bonding the l-azido lysine on silica gel via click chemistry. The key intermediate azido lysine was synthesized by transformation the amino group in l-Boc-lysine to corresponding azido group and subsequent removal of the N-protected group (Boc). Finally, the azido lysine was covalently bonded to silica beads by click chemistry to get click lysine. Its structure was confirmed by FT-IR and elemental analysis. The new stationary phase showed good HILIC characteristics, when it was applied to separate polar and hydrophilic compounds, such as organic acids, cephalosporins and carbapenems. Compared with the commercial stationary phases, such as Atlantics HILIC and ZIC-HILIC, click lysine displayed better or similar chromatographic behaviors.

► A zwitterionic HILIC stationary phase was developed by covalently bonded azido lysine on silica beads by click chemistry.
► This new stationary phase showed good HILIC chromatographic properties.
► Hydrophilic compounds such as cephalosporins and carbapenems could be well separated by using click lysine stationary phase.
► This stationary phase displayed good stability and reproducibility.