Inverse Gas Chromatography for Characterizing Silica Gels as Solid Stationary Phase

Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt. Chemistry Department, Faculty of Science, Taif University, KSA. __________________________________________________________________________________________ Abstract Inverse gas chromatography (IGC) has become an accurate, versatile and fast method to study the physicochemical characteristics of the modified silica gels. The use of this technique in examination of both surface properties and the deactivation degree seems to be especially interesting. The characteristics of untreated and modified silica gels as solid stationary phases via IGC have been evaluated in terms of polarity, selectivity, thermodynamic properties and separation efficiencies. These parameters used to assess the outer silica surface contributions and the degree of surface deactivation brought about by different modification techniques. The silylation technique of the calcined silica gel has a pronounced effect on the surface deactivation due to the formation of the silanol group with the remainder hydroxyl groups. This column is selective one for the elution of polar compounds including alcohols giving sharp and symmetric peaks. The purpose of this work is the application of one patch of the prepared silica to cover gas chromatographic separations of polar and non polar compounds through different modifications in addition to study the interaction between stationart phases and solutes. __________________________________________________________________________________________