Click N-benzyl iminodiacetic acid: Novel silica-based tridentate zwitterionic stationary phase for hydrophilic interaction liquid chromatography

Iminodiacetic acid (IDA) is dicarboxylic acid amine, which may produce stronger interaction with polar or charged compounds than bidentate α,β-amino acid. In this article, a novel type of tridentate zwitterionic HILIC stationary phase was prepared by covalently bonding N-benzyl IDA on silica gel via copper( I ) catalyzed Huisgen azide-alkyne 1,3-dipolar cycloaddition (CuAAC). The structure of this stationary phase and all related intermediates was confirmed by NMR, FT-IR, MS spectrum and elemental analysis . The new stationary phase showed good HILIC characteristics and high column efficiency (the theoretical plate number is up to 44000 plates m −1 in the case of guanosine) in the application of separation of polar compounds, including organic acids , organic bases, as well as highly polar and hydrophilic compounds, such as cephalosporins and carbapenems . Most of them displayed good peak shape and selectivity.