Rate of reaction of dithionite ion with oxygen in aqueous solution

The rate of removal of oxygen from aqueous solution by sodium dithionite in 0.1 m sodium hydroxide was studied in a rapid-reaction apparatus using a membrane-covered polarographic cell to determine Po2 in the flowing liquid. The measurements were made at 37 C, so that the data would be applicable in studies of the kinetics of oxyhemoglobin in blood. The initial concentrations in the mixed reacting solution were between 8 x 10-5 m and 47.5 x 10-5 m for dithionite, and either 10 x 10-5 m or 47.8 x 10-5 m for O2. The reaction over the first 40 msec was found to be first order with respect to dithionite and zero order with respect to molecular oxygen. The initial rate constant was 42.5 ± sd 3.6 sec-1. oxygen reduction by dithionite; hemoglobin; deoxygenation rate; dithionite-oxygen reaction rate Submitted on June 17, 1963