Identification of the Mass transfer mechanisms involved in the transport of human immunoglobulin - G in N,N,N',N' -ethylnediaminetetramenthylenephosphonic acid modified Zirconia

Authors

Sabyasachi Sarkar
Perer W. Carr, University of Minnesota, Department of Chemistry.
Anuradha Subramanian, Department of chemical Engineering,University of Nebraska Lincoln.Follow

Date of this Version

April 2005

Comments

Published in Journal of Chromatography B 821:2 (July 25, 2005), pp. 124-131; doi 10.1016/j.jchromb.2005.04.017 Copyright © 2005 Elsevier B.V. Used by permission. http://www.sciencedirect.com/science/journal/15700232

Abstract

Zirconia particles modified with N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid (EDTPA), further referred to as r_PEZ, were studied as a support material for use in chromatography. Our previous studies have demonstrated the utility of r_PEZ in the separation of immunoglobulins from biological fluids. In the present study we sought to understand the underlying factors and identify the rate-limiting mechanisms that govern the transport of biomolecules in r_PEZ. Pulse injection techniques were used to elucidate the individual mass transfer parameters. Elution profiles obtained under retained and unretained conditions were approximated by the Gaussian equation and the corresponding HETP contributions were estimated. The dependence of the HETP values on incremental salt concentration in the mobile phase was determined. Resulting data in conjunction with the equations outlined in literature were used to estimate the theoretical number of transfer units for the chromatographic separation process. Our results indicate that surface diffusion probably plays a minor role; however pore diffusion was established to be the rate limiting mechanism for immunoglobulin G adsorption to r_PEZ. The HETP based methodology may be used to estimate the rate limiting mechanisms of mass transfer for any given chromatographic system under appropriate conditions.