Simultaneous deactivation and coating of porous silica particles for microcolumn supercritical fluid chromatography

Abstract

A new method for the simultaneous deactivation and coating of porous silica particles for supercritical fluid chromatography (SFC) has been developed. This method is based on a dehydrocondensation reaction between polymeric silicon hydride reagents and the silanol groups on the surface of the particles. The procedure produces a less active surface than conventional silica packings, which results in less adsorption and improved peak shapes for polar analytes. In SFC, more polar analytes can be chromatographed without the need for mobile phase modifiers. Furthermore, the sensitive and universal flame ionization detector (FID) can be used, since modifiers are not necessary. To avoid splitting of the column effluent before FID detection, packed capillary columns were utilized in this study. The ability to use packed capillary columns for the analysis of polar compounds, while at the same time allowing the use of a wide range of detection methods, serves to expand the number of useful applications for packed column SFC.