Evaluation of etched borosilicate glass capillary columns in reversed phase open tubular liquid chromatography

Abstract

Abstract. The performance of etched borosilicate capillary columns with a bonded octadecyl stationary phase has been examined. Plate heights for three test compounds in columns with inner diameters between 6.5 and 14.6 pm were measured as a function of mobile phase velocity. The reduced plate height vs. reduced velocity curves were then fit to the Golay equation using nonlinear regression analysis. It was found that in addition to longitudinal diffusion in the mobile phase, longitudinal diffusion in the stationary phase was a significant contributor to broadening at low mobile phase flow rates. At higher flow rates, resistance to mass transfer in the stagnant mobile phase in the porous glass produced by the etching procedure became measurable.

Preparation and Evaluation of Bonded Linear Polymethacrylate Stationary Phases for Open Tubular Capillary Electrokinetic Chromatography

“…with a bonded monolayer of an octadecyl stationary phase were also evaluated. A tedious nine-step etching procedure was employed before the actual bonding . Precipitation coating followed by cross-linking has been successfully applied to fabrication of stable polymer films inside small-bore fused-silica capillaries .…”

Capillary columns in liquid chromatography: between conventional columns and microchips

“…With the short light path lengths of on-column UV detection, the demands on sample concentrations were high, however, and that focused greater attention on use of the more sensitive fluorescence detector, as demonstrated by Folestad et al [90], Jorgenson and Guthrie [39], and van Berkel et al [91]. Although the practical difficulties of both making and handling extremely small diameter columns are considerable, columns with inner diameters of 10 lm and less were used by Tsuda et al [92], Kreijci et al [93], Folestad and Larsson [94], Simon et al [95], Dohmeier and Jorgenson [96], and Göhlin and Larsson [97].…”

Changes of Two Phase Composition in Phase Separation Process of Na₂O-CaO-Al₂O₃-B₂O₃-SiO₂-TiO₂ System

“…There exist glass phase separation phenomenons in many practical multi-borosilicate systems [1][2][3][4]. A series of new materials and preparation methods were developed according to the concentration phenomenon of two-phase compositions in the phase separation process [5,6]. The titaniferous blast furnace slag contains a large number of SiO 2 , Al 2 O 3 , CaO, MgO and TiO 2 .…”