Open-tubular CEC with a new triethanolamine bonded stationary phase for biomolecule separation

• New method for preparation of open tubular capillary.
• The use of HPMA-Cl as a reactive monomer.
• The characteristic behaviors of the open tubular capillary.
• The real sample application of the synthesized column.

This study describes the preparation and electrochromatographic application of a new open-tubular capillary column with triethanolamine functionalized stationary phase. The stationary phase was synthesized by in situ grafting polymerization with 3-chloro-2-hydroxypropylmethacrylate based reactive monomer, and followed triethanolamine functionalization. The different 3-chloro-2-hydroxypropylmethacrylate contents on the separation efficiency were studied. The results indicated that the 3-chloro-2-hydroxypropylmethacrylate content (e.g., 15.3 v/v%) on the inner surface of the capillary was very important for final preparation of the polymer stationary phase. The electrochromatographic characterization of the stationary phase was performed using alkylbenzene derivatives. The pH effect on the electroosmotic flow was also investigated. The open tubular column functionalized with triethanolamine allowed to operate in the anodic electroosmotic flow mode in the system. With anodic electroosmotic flow mode, favorable separations of the amino acids and the nucleosides were successfully achieved with high column efficiens ranging from 142 000 to 257 000 plates/m. Good repeatability was gained with relative standard deviation of the migration time and peak areas less than 2.2% for run to run (n = 5) and less than 3.2% day to day (n = 3). Furthermore, real sample applicability of this column to the separation of amino acids in white tea sample was demonstrated.