Hydrothermal preparation of hybrid carbon/silica monolithic capillary column for liquid chromatography

Abstract

A simple, easy and economical approach for the preparation of a hybrid carbon/silica monolithic capillary column was described for the first time by using silica monolith as framework in combination with hydrothermal carbonization at 180°C. During the preparation process, formamide was introduced to the reaction solutions to reduce the dissolution rate of monolithic silica skeleton and its optimal concentration was 1.5 M. Fourier transform infrared spectrometry, scanning electron microscopy, energy dispersive X-ray spectrometry, and inverse size exclusion chromatography were carried out to characterize the as-prepared column. The results demonstrated that carbon spheres ranging from 150 to 1000 nm were successfully attached to the surface of silica skeleton. The prepared hybrid carbon/silica column had a permeability of 4.4 × 10(-14) m(2). Chromatographic performance of the column was evaluated by separation of various compounds including alkylbenzenes, nucleosides and bases, and aromatic acids. The column exhibited an efficiency of 75,000 plates/m for butylbenzene at the optimal linear velocity of 0.23 mm/s. The successful separation of these compounds and the study on mechanism indicated that the column can be applied in mixed-mode chromatography.

Advances in the development and applications of organic–silica hybrid monoliths

“…Hybrid carbon/silica monolithic columns prepared by hydrothermal carbonization of glucose on the surface of TMOS/MTMS monoliths are also suitable as separation media in mixed‐mode chromatography due to hydrophobic cores and hydrophilic surfaces of formed carbon spheres. Hydrophilic properties of the surface can be attributed to the presence of unreacted carboxyl and hydroxyl groups of the glucose.…”

Histidine-modified organic-silica hybrid monolithic column for mixed-mode per aqueous and ion-exchange capillary electrochromatography

“…According to the nature of matrix chemistry, monolithic columns can be mainly classified into organic polymer-based [8][9][10][11], inorganic silica-based [12][13][14], and organic-silica hybrid monolithic columns [15][16][17][18][19][20][21][22][23]. Organic polymer-based monolithic columns show good stability toward pH changes and their surfaces can be easily tuned by using a variety of functional monomers and cross linkers.…”

“…In recent years, monoliths, which can be described as integrated continuous porous separation media for separation science, have become well‐established stationary phases in the field of CEC due to the simplicity of their in situ preparation method, ready control of their porous properties and surface chemistries as well as their unique structure and exceptional characteristics . According to the nature of matrix chemistry, monolithic columns can be mainly classified into organic polymer‐based , inorganic silica‐based , and organic‐silica hybrid monolithic columns . Organic polymer‐based monolithic columns show good stability toward pH changes and their surfaces can be easily tuned by using a variety of functional monomers and cross linkers.…”

Adsorption Isotherms of Hydrophobic Substances onto a Chromatographic Organic Monolith

“…Silica monoliths have high mechanical strength [2], and organic monoliths can be chemically modified in various ways after preparation [3]. The preparation and characterization of monoliths have been extensively investigated [4,5]. In order to use the monoliths reasonably, their adsorption characteristics with various adsorbates should be considered.…”