Characterization and optimization of a chromatographic process based on ethylenediamine-N,N,N′,N′-tetra(methylphosphonic) acid-modified zirconia particles

The primary objective of work was to characterize, optimize and model a chromatographic process based on ethylenediamine-N,N,N′,N′-tetra(methylphosphonic) acid (EDTPA)-modified zirconia particles. Zirconia particles were produced by spray-drying colloidal zirconia. Zirconia spheres produced were further classified, calcined and modified with EDTPA to yield a solid-phase support for use in bio-chromatography (r_PEZ). Specifically, the ability of r_PEZ to selectively bind and enrich IgG, IgA, and IgM from biological fluids was evaluated and demonstrated. To better understand the force of interaction between the IgG and the r_PEZ, the equilibrium disassociation constant (Kd) was determined by static binding isotherms, as a function of temperature and by frontal analysis at different linear velocities. The maximum static binding capacity (Qmax) was found to be in the range 55–65 mg IgG per ml of beads, and unaffected by temperature. The maximum dynamic binding capacity (Qx) was found to be in the range 20–12 mg IgG per ml of beads. The adsorption rate constant (ka) was determined by a split-peak approach to be between 982 and 3242 l mol−1 s−1 depending on the linear velocity. The standard enthalpy and entropy values were estimated for this interaction of IgG with this novel support.