Novel open tubular CEC with tentacle‐type polymer stationary phase functionalized by phenylalanine

Abstract

A novel stationary phase with tentacle-type polymer chains with epoxy groups was fabricated for open tubular CEC. The fabrication procedure of the stationary phase included pretreatment of capillary inner wall, silanization, and glycidyl methacrylate (GMA)-grafted polymerization. The influence of initiator concentration and polymerization time on the resulting polymer stationary phase was studied by measuring EOF mobility and hydrophobicity of the prepared capillary column. SEM showed that the capillary inner wall was evenly coated with a polymer film showing a wrinkly surface. The prepared GMA-grafted stationary phase could be easily modified with different chromatographic ligands by the ring-opening reaction of the epoxy groups. In this study, phenylalanine (Phe) was selected as the ligand. Benzene derivatives and three amino acids were then separated, respectively, using the Phe modified tentacle-type capillary column. As a control, separations were also performed on a monolayer Phe-modified capillary. The tentacle-type polymer stationary phase was found affording stronger retention and better resolution in the separation of benzene derivatives and tryptophan, tyrosine, and Phe mixtures compared with the monolayer stationary phase.

Assay of vitamin B in urine by capillary electrochromatography with methacrylate‐based monolithic column

“…The results suggested that the capillary with monolithic layer exhibited less separation efficiency than the capillary with monolithic column. This might be due to a lower phase ratio for interactions with analytes in the OTcapillary CEC, which could cause broadening and skewing of solute bands, thereby lower resolutions in separations [24]. Meanwhile, capillary columns with monolithic stationary phases had greater phase ratios than OT-capillary columns [25][26][27], and thus, resulting in a high separation efficiency for five analytes.…”

Preparation and characterization of tentacle-type polymer stationary phase modified with graphene oxide for open-tubular capillary electrochromatography

“…However, the OT capillary column still bears the primary shortcoming of low phase ratio that impeding its wide application in chromatography separation. In order to overcome the above limitation, several attempts, such as etching the capillary [1], porous polymer layer [2][3][4][5], sol-gel techniques [6,7] and nanoparticle coating [8][9][10] have been made to increase the surface area, therefore to greatly improve the OT-CEC performance.…”

Novel negatively charged tentacle‐type polymer coating for on‐line preconcentration of proteins in CE

“…Recently, we prepared a few tentacle-type polymermodified capillary columns for open tubular capillary electrochromatographic separations of neutral analytes, amino acids, and proteins [18][19][20]. Both capillary inner surface area and ligand capacity were largely increased by coating the tentacle-type polymers, which can provide high analyte adsorption capacity.…”