Porous Silica Monolithic Polymers for Micromachined Gas Chromatography Columns: A Featured Phase for Fast and Efficient Separations of Light Compounds Mixtures

Abstract

Since the late 1970s, approaches have been proposed to replace conventional gas chromatography apparatus with silicon-based microfabricated separation systems. Performances are expected to be much improved with miniaturization owing to the reduction of diffusion distances and better thermal management. When it is easy to microfabricate miniaturized parts, the main challenge consists, however, to produce stable, efficient, and functionalized columns. The purpose of the paper is to transpose and adapt monolith synthesis in-situ micromachined gas chromatography columns. Silica-based monolithic microcolumns based on the sol–gel process were tested in the course of high-speed gas chromatographic separations of light hydrocarbons mixture (C1–C4). At the optimum separation conditions, a very good resolution (2.14) for very light compounds (C1–C2) was reached on a 50 cm microcolumn at room temperature with a back-pressure within the range used at gas chromatography facilities (without external modification of the device). The versatility of these microelectromechanical systems (MEMS) columns was demonstrated with a high-temperature C1 – C2 separation, and unsaturated cyclic alkanes. Light halogenated alkanes were also successfully separated. These columns should be used in various applications related to oil/gas and environment field analyses.