Investigation of the Retention Mechanism of Chemically Bonded Stationary Phases in Gas Chromatography

Abstract

The investigation of the retention mechanism for ≡SiOR- type chemically bonded stationary phases with functional groups has been conducted using sample-size studies and thermodynamic parameters. Comparison is also made between retention behavior on conventionally coated and chemically bonded columns. The effect of support surface properties is also determined. In the absence of surface -OH groups, retention is controlled by adsorption on the brush. If surface hydroxyls are present, retention of certain solutes is controlled by interaction with these groups. The retention of other solutes is controlled by brush adsorption even in the presence of hydroxyl groups and in some cases retention can be a combination of both mechanisms.