A new designed cell for luminol based electrochemiluminescence by bi-potentiostatic excitation for flow-injection analysis

A new designed luminol-based electrochemiluminescent (ECL) cell by bi-potentiostatic excitation was developed for the utilization as a coupled-detector of a flow injection analysis system (Bi-ECL-FIA). In this flow cell, four electrodes were fixed in, here a piece of indium tin oxide coated glass was applied as one of the working electrodes while another Pt net served as second one. Two electrolysis voltages from a dual-potentiostat powered two working electrodes. Thus, continuous and constant ECL signal could be obtained. After optimizing the experimental conditions, it was showed that the Bi-ECL-FIA system provided higher sensitivity than conventional pulsed mode. The response of hydrogen peroxide or resveratrol on this system was investigated, indicating a 7.4 x 10(-11) mol/L of detection limit for H2O2 and 8.8 x 10(-8) mol/L for resveratrol. The system was successfully employed to value the gross activity of antioxidants of peanut using resveratrol as the index. The results suggested a good recovery within the range from 88.8% to 109.1%. (C) 2014 Elsevier B.V. All rights reserved.