This Career Advancement Award will allow Dr. Wells to acquire new skills in the analytical separations area of field flow fractionation. Field flow fractionation is capable of resolving and characterizing a broad range of macromolecular, colloidal, and particulate materials. This project focuses on the separation of large molecules of environmental importance by these methods. Field flow fractionation will be used to determine the molecular weight and polydispersity of dissolved organic macromolecules and will be useful in studies of the interactions between fractionated macromolecules and anthropogenic environmental contaminants. This is of substantial environmental significance. The objectives of this activity are to establish greater competence in the theory and application of field flow fractionation. This technique will be used in experiments aimed at understanding the chemistry of naturally-occurring macromolecules such as humic and fulvic acids and their constituents. Determinations of molecular weight and polydispersity, and semi-preparative recovery of these macromolecules will be emphasized. %%% This Career Advancement Award will support activities that will expand Dr. Wells' research career potential. The award will provide for the acquisiton of new skills in areas that will enrich her research activities. This activity will complement her previous professional activities in government and industry.