The electrochemical behavior of the nitro radical anion, RNO2.-, of furazolidone has been investigated to study the tendency of RNO2.- to undergo further chemical reaction. The study was carried out in dimethylformamide (DMF) + water mixtures at different pH values on both mercury (Hg) and glassy carbon (GC) electrodes. The subsequent chemical reaction corresponds to a second order process; protonation of the electrogenerated RNO2.-. The procedure of Olmstead et al. [Anal. Chem. 41 (1969) 260] was employed to calculate the second order rate constant, k(2). The k(2) values are strongly pH-dependent. The interaction of RNO2.- with cysteine has been studied on a GC electrode, and the apparent rate constant, k(app), reported. (C) 2004 Elsevier B.V. All rights reserved.