DESIGN AND SYNTHESIS OF CHELATING COMPOUNDS AND SOLID-SUPPORTED CHELATORS FOR METAL DEPLETED SOLUTIONS
Doctor of Philosophy
Date of Defense
Christopher Spilling, PhD
Wesley R. Harris
James J. O'Brien
Alexei V. Demchenko
Metals are essential to life, yet they can be toxic for biological systems when present in excessive amounts. The major source of metal overload in humans is diet; and in some cases, intravenous feeding. Thus the removal of toxic metal ions from contaminated clinical products such as total parenteral nutrition (TPN) solutions, and drinking and waste water is extremely important. The use of chelating resins, which are polymeric solids containing covalently immobilized chelating compounds, for the selective removal of metal ions from contaminated solutions has been conceptualized long ago. Herein, the design and synthesis of metal specific chelating compounds and chelating resins will be presented, along with the application of these materials to remove toxic metals from aqueous solutions. Solution phase hydroxamate based chelating compounds have been synthesized for the selective binding of trivalent metals such as iron and aluminum in the presence of divalent metals such as calcium. Iron complexation behavior of these solution phase chelating compounds has been studied by UV-Vis Spectrophotometric methods. These hydroxamate chelators have potential applications as chelating agents in the treatment of iron and aluminum overload. A set of the strongly binding chelators have been immobilized on solid support via various linkages. These solid supported chelators have been employed to selectively remove aluminum from contaminated TPN components such as a solution of calcium gluconate. Our resins are able to remove more than 90% of aluminum from commercial calcium gluconate solutions. This technology of employing hydroxamate functionalized resins for the removal of aluminum from calcium gluconate solution will be available in hospitals soon and will greatly benefit premature neonates who receive TPN solutions for life support. Additionally, citramide functionalized chelating resins have been prepared for the removal of trivalent metals from contaminated solutions at low pH, and dithiolate based chelating resins were prepared for the removal of high priority environmental metal toxins such as lead, cadmium, mercury, and arsenic. Overall, this dissertation embodies the design, synthesis, and metal binding studies of novel chelators and chelating resins and the applications of these resins for the selective removal of metal ions from contaminated solutions.
Dawadi, Surendra, "DESIGN AND SYNTHESIS OF CHELATING COMPOUNDS AND SOLID-SUPPORTED CHELATORS FOR METAL DEPLETED SOLUTIONS" (2014). Dissertations. 230.