Angeli's salt (Na2N2O3) is a precursor of HNO and NO:: a voltammetric study of the reactive intermediates released by Angeli's salt decomposition

Under physiological conditions, it is usually accepted that the aerobic decomposition of Angeli's salt produces nitrite (NO2-) and nitroxyl (HNO), which dimerizes and leads to N2O. No conj sensus has yet been established on the formation of nitric oxide (NO) and/or peroxynitrite (ONOO-) by Angeli's salt. Because this salt has recently been shown to have pharmacological properties for the treatment of cardiovascular diseases, identification of its follow-up reactive intermediates is of increasing importance. In this work, we investigated the decomposition mechanism of Angeli's salt by voltammetry performed at platinized carbon fiber I microelectrodes. By following the decomposition process of Angeli's salt we showed that the mechanism depends on the experimental conditions. Under aerobic neutral and slightly alkaline conditions, the formation of HNO, NO2-, but also of nitric oxide NO was demonstrated. In strongly alkaline buffer (pH > 10), we observed the formation of peroxynitrite ONOO- in the presence of oxygen. These electrochemical results are supported by comparison with UV spectrophotometry, data.