Improved method for end-column amperometric detection for capillary electrophoresis

Capillary electrophoresis (CE) with end-column amperometric detection is described. The coulometric efficiency obtained with this method depends strongly on the alignment of the capillary and the electrode. An improved design for end-column detection in CE is also presented. This new design involves etching the detector end of the capillary so that alignment of the capillary bore and the electrode is easily maintained. Optimized end-column detection provides detection limits as low as 11 amol with peak efficiencies of 140 000 theoretical plates for catechol. optimized end-column detection also allows the routine use of 2-μm-i.d. capillaries in CE