Monolithic Silica Capillary Columns with Improved Retention and Selectivity for Amino Acids

Abstract

A strategy for the preparation of silica-based monolithic capillary columns (150 × 0.1 mm) with high selectivity to amino acids is presented. The zwitterionic columns were prepared by coating the silica monolith with [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)-ammonium hydroxide via 3-(trimethoxysilyl)propyl methacrylate. The columns were evaluated under isocratic conditions in hydrophilic interaction liquid chromatography. The best separation of amino acids was obtained on the monolithic column prepared by a stepwise modification procedure where the modification step was repeated four times. The mixture of fifteen amino acids was separated within 13 min using the mobile phase consisting of 75% acetonitrile and 25% 5 mmol/L ammonium acetate at pH 4.5.

Insights into the Mechanism of Separation of Bisphosphonates by Zwitterionic Hydrophilic Interaction Liquid Chromatography: Application to the Quantitation of Risedronate in Pharmaceuticals

“…Electrostatic repulsions in HILIC were first described by Alpert [26] as electrostatic repulsion hydrophilic interaction chromatography (ERLIC). These kinds of interactions were of great interest and can be used to selectively antagonize the retention of analytes that normally would be best retained [27].…”

“…great interest and can be used to selectively antagonize the retention of analytes that normally would be best retained [27].…”

Recent Developments of Liquid Chromatography Stationary Phases for Compound Separation: From Proteins to Small Organic Compounds

“…Each molecule interacts differently due to their different functional groups, atomic numbers, and 3D structures. This difference allows for the separation of analogue [ 7 ] and homologous compounds [ 8 , 9 ].…”

Molecular dynamics simulations of amino acid adsorption and transport at the acetonitrile–water–silica interface: the role of side chains

“…21 In particular, as the most commonly used separation method in biochemistry, the hydrophilic interaction liquid chromatography (HILIC), which is comprised of polar stationary phase and aprotic mobile phase, is widely utilized to separate the amino acids samples. [22][23][24][25][26][27] At the microscopic level, the interactions between the stationary phase and amino acids as well as the mobile phase determine the actual separation efficiency. Therefore, controlling the interaction between amino acids and mineral surfaces plays a crucial role in improving the separation, purication, and retention of amino acids in practical application.…”

“…21 In particular, as the most commonly used separation method in biochemistry, the hydrophilic interaction liquid chromatography (HILIC), which is comprised of polar stationary phase and aprotic mobile phase, is widely utilized to separate the amino acids samples. 22–27 …”