DICARBONYLS AS S(IV) RESERVOIRS.

S(IV) in the form of SO//2 multiplied by (times) H//2O, HSO//3** minus or SO//3**2** minus reacts with glyoxal to yield 1,2-dihydroxy-ethanedisulfonate (DHES) and it reacts with methylglyoxal to yield 1-hydroxyacetylmethanesulfonate (HAMS). The kinetics of both the association and the dissociation of the aldehyde-bisulfite adducts was studied in aqueous solution as a function of pH. The rate of association was studied directly by UV-visible spectrophotometry under pseudo-first-order conditions while the rate of dissociation was studied indirectly by using an iodide electrode to measure the rate of formation of I** minus as the sulfonates dissociated in I//2 solution.