The γ-radiolysis of cysteine in deaerated 1 N HClO4 solutions

The G values for the formation of H2, H2S, alanine (CyH), and cystine ((CyS)2) in the 60Co γ-radiolysis of 10−3 and 10−2 M solutions of cysteine (CySH) in 1 N perchloric acid at 23 °C have been determined. They are quantitatively consistent with the following reaction mechanism. The yields of H2 and H2S have also been measured at 1 ± 1°C. If H atoms are assumed to be the only reducing species in 1 N perchloric acid, k1/k2 was found to be 3.5 at 23 °C and 8 at 1 °C.