Applications of Frontal Affinity Chromatography to the Study of Interactions between Metal Ions and a Complex Biomaterial

The use of frontal affinity chromatography for the study of metal-biomaterial interactions is described. Both normal frontal affinity chromatography and a modification of this methodology were used to generate metal binding isotherms to a biomaterial. This modification enabled the acquisition of binding isotherms with extended concentration ranges at the expense of time-dependent binding information. Comparison between normal and modified mode was made by using a well-defined commercial resin. Similar performance of these two modes was obtained. The biomaterial investigated was composed of cell fragments from the plant Datura innoxia which were immobilized within a polysilicate matrix. The application of a regularized least-squares method indicated the existence of two classes of sites on this biosorbent involved in the binding of Ag(+). A total metal-ion binding affinity order at solution pH 3-5 was determined to be Cu(2+) > Cd(2+) ≈ Ag(+) > Ca(2+).