The formation of constants of mercury(II)--glutathione complexes.

The formation constants of the 1:1 and 1:2 complexes of Hg(II) with glutathione and their protonated species have been determined by using a competitive potentiometric titration with the competing ligand diethylenetriaminepentaacetic acid (DTPA). The formation constants of the 1:1 complex and its protonated species have not been reported previously. The formation constant of the 1:2 complex of Hg(II) and glutathione is substantially smaller than the accepted values that has been reported in the literature.