Characterization of a Chemically Bonded Stationary Phase with Kinetics in a Liquid Chromatographic Reactor

摘要

Liquid chromatographic columns are shown to be operable as chemical reactors for investigating solute-stationary phase interactions in reversed-phase systems. The kinetics of several organic base-catalyzed esterification reactions of tetrachloroterephthaloyl chloride (TCTPCI2) and its half ester 4-(methoxycarbonyl)-2,3,5,6-tetrachlorobenzoyl chloride were studied in a liquid chromatographic reactor (LCR). The comparison of on-column rate constants in the methanol mobile phase and the methanol solvated octadecylsilane bonded stationary phase illustrates and additional method for obtaining information about the character and composition of chemically bonded chromatographic systems. These kinetic results favor a generalized stationary phase model which involves methanol molecules associated with the hydrocarbon ligands of the support surface. Deviations from avalues for an idealized model suggest that there are associated methanol concentration variations at the mobile-stationary phase boundary and the silica surface, some of which may be due to geometric and steric effects.