Radiolysis of Aqueous Solutions of Ammonium Bicarbonate Over A Large Dose Range

Authors: Z. D. Draganić , A. Negrón-Mendoza, K. Sehested, S.I. Vujošević, R. Navarro-Gonzáles, M. G. Albarrán-Sanchez, I. G. Draganić

Oxygen-free aqueous solutions of 0.05 mol dm^(-3) ammonium and sodium bicarbonate were studied after receiving various doses of 60Co gammas (0.01-400kGy) or 0.5-20Gy pulses of 10Mev electrons. Formate and oxalate were found to be the main radiolytic products, in addition to trace amounts of formaldehyde and an unidentified polymer. A large initial yield of formate in the y-radiolysis, G(HCO0-) =2.2,is due to the reaction CO0- + HCO ⇌ HCOO-+CO~-. The efficiency of organic synthesis within the large dose range studied is low and is explained by efficient pathways leading to the reformation of bicarbonate, where the reaction COO-+CO~-is particularly significant. Computer fitting of the data obtained gives k(COO-+HCOf)=(2+0.4)x103dm3mol-ts-t, k(COO-+COj-)= (5+ 1)x 107dm3mol-Is-i, k(NH2+HCO~-)< 10^(4)dm^(3) mol^(-1) s^(-1),and k(NH2+CO3-)=(1.5+0.5)x 109dm3mol-i s- ~.

https://doi.org/10.1016/1359-0197(91)90100-G