Nitrite formation in aerated aqueous azide solutions: A radiation chemical study

摘要

Gamma radiolysis of oxygenated 1–10 mM azide solutions was carried out at various pH values. In oxygenated 10 mM azide solutions, H2O2 and NO 2 ? were observed as radiolytic products while NH3 was not. The concentration of H2O2 reached its maximum level at a dose of 1 kGy, whereas NO 2 ? yield increased non-linearly beyond 2 kGy in this system. Both in aerated and oxygenated systems, G(NO 2 ? ) and G(H2O2) were found to vary with N 3 ? concentration. The yield of NO 2 ? was found to be dependent on both dose rate and pH. On pulse radiolysis, NO 2 ? was found as a radiolytic product in aerated 1 mM azide solution at pH 6.8. In this system the intermediate generated exhibits absorbance around 250 nm. The overall results obtained during the present study reveal that in presence of both reducing radical (mainly e aq ? ) and oxygen, N 3 ? produced an intermediate possibly NH2O 2 ? radical, which is the prime source for NO 2 ? generation.