Modification of the inner capillary surface by the sol‐gel method: Application to open tubular electrochromatography

The sol‐gel procedure was used to prepare an organically modified silica glass coating material which was used as the stationary phase for reversed‐phase open tubular electrochromatography. The unique column preparation scheme is simplified by combining the synthesis of the stationary phase and the attachment of the supporting porous glass matrix in a single‐step procedure. This approach significantly increases surface area which results in a higher phase ratio. Controlling the amount of the precursor materials used in the sol‐gel solution provides a means to adjust the carbon content in the stationary phase. The column performance was evaluated using a test mixture of polycyclic aromatic hydrocarbons; under certain experimental conditions, efficiencies around 500,000 theoretical plates per meter were obtained for some test solutes.