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Updated: Oct 9, 2026

Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography
Published on: May 16, 2014
The synthesis and characterization of chemically bonded silica-based zwitterion-exchangers for HPLC
Abstract:
The synthesis and characterization of a zwitterionic stationary phase bonded onto microparticulate silica is described. The bonded zwitterionic phase was characterized by elemental analysis, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and quantitative analysis of the ligands by high performance liquid chromatography (HPLC) following chemical cleavage from the silica backbone. Chromatographic evaluation of this novel bonded phase indicates that it functions as a weak cation exchanger at pH values above 4.5, an anion exchanger at pH values below 7, and as a zwitterionic phase between these two values. The simultaneous separation of a mixture of cationic, anionic and zwitterionic solutes with this novel bonded phase is shown. Using nucleotides as model compounds, a correlation was developed between maximum solute retention and the pH values corresponding to maximum solute/stationary phase zwitterion overlap. The possibility for a quadrupolar retention mechanism of the bonded zwitterionic phase for zwitterionic solutes is explored.
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