Mixed-Mode Retention on a Hypercrosslinked Silica-Based Column

Column stability in Reversed Phase Liquid Chromatography (RPLC) is crucial for obtaining reproducible separations. Under acidic conditions RPLC columns may exhibit stationary phase loss. To address this problem various concepts for improving column acid resistance have been proposed. Carr and co-workers introduced a class of acid stable silica-based RPLC stationary phases based on extensive bonded phase crosslinking. This technology results in the formation of a surface-confined hypercrosslinked polymeric network. One aspect of the column preparation that was not detailed in the literature and is rather perplexing is the column acid conditioning.;This thesis explores the synthesis and chromatographic performance of a toluene-derivatized hypercrosslinked silica-based stationary phase (HC-T). This work focuses on the long-term chemical stability and chromatographic behaviour of HC-T after continuous exposure to acid and temperature extremes. It has been demonstrated that the acid treatment results in the formation of cationic functionalities on the hypercrosslinked bonded phase.