On-column amperometric detection in capillary electrophoresis with an improved high-voltage electric field decoupler

An improved fabrication method for a decoupler for on-column amperometric detection in capillary electrophoresis (CE) is described. The decoupler is fabricated by etching one side-wall of the capillary with hydrofluoric acid after the polymer coating had been etched by laser, then the etched hole is sealed with adhesive. The steady time, electric conductivity efficiency and performance are investigated. On-column amperometric detection by CE of para-substituted phenols was carried out by coupling with a carbon-fiber microelectrode (10-microm diameter) and a practical small electrochemical detection cell.