Development of a statistical model for metal-humic interactions

Abstract

A statistical model for describing the distribution of binding sites in humic substances was developed. The model was applied to study the spectral titration plot generated by the lanthanide ion probe spectroscopy (LIPS) technique. This titration plot is used as a basis for studying the interactions between metal ions and humic binding sites. Humic samples were titrated with Eu{sup 3+}, which acts as the fluorescent probe ion. The competition effects between a proton, a metal ion other than the probe ion, and the probe ion itself in binding with the humic binding sites, as well as the electrostatic effects, are successfully predicted and described by the model.