关键词: 粉末微电极, 谷胱甘肽, 抗坏血酸, 尿酸, 抗氧化剂

Abstract: In this paper, the electrochemical behavior of GSH at the surface of platinum(Pt) electrode, glass carbon(GC) electrode and acetylene black packed powder microelectrode (AB-PME) was studied. It was found that the electrochemical oxidations of GSH at both Pt and GC electrode were highly irreversible. No current peak or current plateau could be observed from the CV curves. The direct electro-oxidation of GSH at carbon surface was achieved by using the PME technique.In this case, the apparent reversibility of GSH oxidation was enhanced significatly .The overpotential of GSH oxidation was reduced to 0.5 V at the surface of AB-PME compared with that obtained with Pt and GC electrodes. The exhaustive electrolysis of GSH within the micro-cavity of the PME can be achieved. As a result, the peak currents obtained with AB-PME were proportional to GSH concentration. The interference caused by ascorbic acid and uric acid was eliminated completely by employing AB-PME electrode. The concentration of GSH in human erythrocyte was determined by employing the AB-PME technique and using the method of ”internal standard addition”. The steady state polarization curve of GSH was obtained with the AB-PME electrode .The number involved in the electrochemical oxidation of GSH was calculated as 1 by using the value of I_(L).

Key words: Powder microelectrode, GSH, Antioxidant, Ascorbic acid, Uric acid