SQUARE-WAVE VOLTAMMETRY DETECTION FOR CAPILLARY ELECTROPHORESIS

A square-wave voltammetry (SWV) detection method for capillary electro phoresis (CE) using end-capillary detection is investigated. Although sensitive detection methods have been reported using off-capillary ele ctrochemicaI detection methods, these methods typically use fragile ca rbon fiber electrodes and complex decoupling apparatus to separate the high separation voltage from the detection electronics; While end-col umn detection systems are not usually as sensitive as off-column techn iques, they require much simpler instrumentation and are more robust. By modifying the Osteryoung SWV method to accommodate the high-frequen cy sample rate required by CE, a detection limit of 5 x 10(-7) M (S/N = 10) was obtained for dopamine using end-capillary detection, which i s comparable to sensitivities obtained using off-capillary detection w ith amperometric detection.