A carbosilane dendrimer bonded silica as the stationary phase for capillary electrochromatography

Abstract

A novel carbosilane dendrimer bonded silica (G2-silica) was synthesized and evaluated as a potential chromatographic resin. The G2-silica was characterized by using various analytical techniques, such as infrared spectroscopy, elemental analysis and loss on ignition analysis. The G2-silica was packed into a capillary and used as the stationary phase for capillary electrochromatography (CEC). The packing characteristics such as the electric current vs. the applied voltage, the effects of voltage, pH, and acetonitrile concentration on EOF, the hydrophobic selectivity, and the repeatability were all investigated. Seven model compounds including thiourea, benzene, ethyl benzene, butyl benzene, benzyl alcohol, toluene and naphthalene were well separated on the CEC column with the separation efficiencies ranging from 40 000 to 90 000 plates per meter. The repeatability was satisfactory with the RSD of the migration time (2.4%). These results indicate that carbosilane dendrimer bonded silica can be used as a novel packing material which has the characteristics of a typical reversed phase.