Speciation of Binary Complexes of Pb(II), Cd(II) and Hg(II) with L-Valine in Low Dielectric Media

Speciation of binary complexes of Pb (II), Cd (II) and Hg (II) in 0.0-60.0 % v/v 1, 2-Propanediol-water mixtures with L-valine at an ionic strength of 0.16 mol L-1 and 303.0 K was studied pH metrically. The approximate formation constants obtained by classical methods are refined using MINIQUAD75 computer program. The binary species confirmed are ML and ML2 for Pb (II), Cd (II) and Hg (II). The species distribution, which gave the important information regarding the extent of formation various species with pH and the effect of influential parameters on stability constants were also studied.