Preparation of silica and mixed oxides monoliths for use in capillary liquid chromatography

Abstract

The aim of this project is to synthesize and apply new monolithic silica-based stationary phases (SP) and silica modified with zirconium and titanium with poly(methyloctylsiloxane) SP to be used in capillary liquid chromatography in the HILIC (hydrophilic-interaction chromatography) and reversed-phase (RP) modes. The preparation of monoliths will use the process sol-gel, and the reaction parameters of the preparation of monolithic stationary phases, as well as the evaluation of polymer immobilization (for time and temperature) will be evaluated. The best experimental conditions will be used in the synthesis of new stationary phases, which will be characterized by physical-chemical and chromatographic techniques. The physical-chemical characterizations will be performed by utilization of optic and electronic microscopies, thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, solid-state 29Si and 13C CP-MAS NMR spectroscopy, elemental analysis, and the chromatographic characterization will use test mixtures described by the literature for capillary monolithic columns for HILIC and reversed modes. The chemical stability of new stationary phases will be evaluated in the separation of solutes with different polarities in drastic conditions of pH, acidic and basic media (pH 1.7 e pH 10) and high temperatures. (AU)