Very fast capillary electrophoresis with electrochemical detection for high-throughput analysis using short, vertically aligned capillaries.

Abstract

A method for conducting fast and efficient capillary electrophoresis (CE) based on short separation capillaries in vertical alignment was developed. The strategy enables for high-throughput analysis from small sample vials (low microliter to nanoliter range). The system consists of a lab-made miniaturized autosampling unit and an amperometric end-column detection (AD) cell. The device enables a throughput of up to 200 separations per hour. CE-AD separations of a dye model system in capillaries of only 4 to 7.5cm length with inner diameters (ID) of 10 or 15μm were carried out under conditions of very high electric field strengths (up to 3.0kV/cm) with high separation efficiency (half peak widths below 0.2s) in less than 3.5s migration time. A non-aqueous background electrolyte, consisting of 10mM ammonium acetate and 1M acetic acid in acetonitrile, was used. The practical suitability of the system was evaluated by applying it to the determination of dyes in overhead projector pens.