A Stationary Phase for Open Tubular Liquid Chromatography and Electrochromatography Using Sol-Gel Technology

Abstract

An organic-inorganic hybrid material was fabricated by the sol-gel method and cast as a thin glass film onto the inner walls of fused silica capillary columns. The thin film in the capillaries functioned as the stationary phase for reversed phase open tubular liquid chromatography (OTLC) and open tubular electrochromatography (OTEC). The stationary phase provides high surface area and thus an improved phase ratio. Multiple preparation steps are avoided by attaching the stationary phase and increasing the surface area in a single procedure. By adjusting the ratio of the monomeric precursors in the original sol-gel solution, the retentive characteristics of the stationary phase are controlled. This new approach facilitates column preparation for OTLC and OTEC. Capillary columns prepared in this manner showed retention characteristics superior to conventionally prepared ones. Polycyclic aromatic hydrocarbons were used to evaluate the stationary phase; under the experimental conditions used, efficiencies of 204 000-285 000 and 280 000-500 000 plates/m were observed in OTLC and OTEC, respectively. The sol-gel-derived stationary phase was shown to be stable under acidic and basic conditions.Open tubular liquid chromatography (OTLC) and open tubular electrochromatography (OTEC) have shown a great potential to reach high efficiencies for the analysis of complex sample mixtures.1™3 The preparation of the stationary phase is of key importance to achieve the high performance offered by these(1) Dorsey,

Analytical Conditions and Separation Performance of Capillary Chromatography Based on the Tube Radial Distribution of Aqueous-Organic Mixture Carrier Solvents under Laminar-Flow Conditions

“…For example, the inner wall of the tube was coated with silicone grease (SE-30 8 ) or modified with a monolayer particle phase. 9 Porous silica structures were also introduced on the wall by dynamic or static coating techniques, [10][11][12] and various polymeric siloxanes were immobilized on the walls. 13,14 We modified the inner walls with specific functional groups or molecules, such as phenylboronic acid, iminodiacetic acid, and antibodies for capillary chromatography to take advantage of specific interactions between the solutes and the modified walls.…”

Hybrid organic-inorganic phenyl monolithic column for capillary electrochromatography

“…The structural property and selectivity of the sol-gel hybrid stationary phase can be easily tailored through changing the composition of original sol solution. Colón et al [16,17] used a sol-gel approach to prepare organic-inorganic hybrid C 8 coatings by copolymerization of tetraethoxysilane (TEOS) and octyltriethoxysilane for opentubular CEC. Hayes and Malik [18,19] prepared open-tubular and monolithic capillary columns with surface-bonded octadecylsilane (ODS) ligands in a single step by solgel process.…”

Sol-gel Technology for Sensor Applications

“…Sol-gel-derived metal chalcagonides (CdS, ZnS, CdTe), titanium oxides and other nanocrystalline semiconductor-doped xerogels are also used as promising sensing materials because of their photocatalytic activity and good optical characteristics 32 . Sol-gel processing has also been used to form stable chromatographic stationary phase 33 . Colloidal silica powders synthesised by sol-gel method are extensively used commercially as catalytic supports, for modifying surface properties of synthetic films, increasing the hardness, durability, and integrity of coatings 34 .…”