Dr. Stout will study the interaction of metal ions with natural polyelectrolytes. With the ultimate aim of characterizing metal ion-humic acid binding, she will initially examine some systems that are less complex. A carboxylate-substituted polysaccharide, alginic acid, will serve as the first model polyectrolyte since, it shares many of the properties of humic acid, but is structurally well-defined. The mode and extent of Eu3+ metal ion binding to alginic acid will be investigated using lanthanide luminescence spectroscopy. As a result of these studies, Dr. Stout will have a better understanding of the potential of lanthanide luminescence spectroscopy for use in subsequent work with humic acids as well as the limitations of the technique. %%% Research Planning Grants enable women who have not had prior independent Federal research support to develop a competitive research project. This project involves the use of ionic probes that luminesce to gain knowledge about the identity and nature of the binding site for metals thus revealing substantial information about the nature of polyelectrolytes such as humic acid. This project may have important consequences in environmental chemistry.