Cyclic voltammetry (CV) was used to promote the production and accumulation of o-quinone-glutathione adduct at a glassy carbon electrode, which is the nucleophilic addition adduct of glutathione to o-quinone. The reduction peak of o-quinone-glutathione adduct could be separated preferably from o-quinone in the differential pulse voltammogram (DPV). As a result, glutathione was determined by differential pulse voltammetry (DPV) separately. The influence of pH value, catechol concentration and cyclic voltammetric conditions on the peak current of o-quinone-glutathione adduct were was investigated in DPVthe differential pulse voltammetry. . Under the optimum conditions, the voltammetric detection limit for glutathione was 0.05 μmol/L, the linear concentrations range was 0.1μmol/L～1.7 μmol/L. The selectivity of the method was assessed with no interference from ascorbic acid, glycine, L-tyrosine, L-lysine or cysteine. The This method of electrochemical determination of glutathione has good selectivity and high sensitivity.

Key words: glutathione, catechol, differential pulse voltammetry, cyclic voltammetry