Sorption kinetics, proteins

On the other hand, the lack of internal pore structure with micropellicular sorbents is of distinct advantage in the analytical HPLC of biological macromolecules because undesirable steric effects can significantly reduce the efficiency of columns packed with porous sorbents and also result in poor recovery. Furthermore, the micropellicular stationary phases which have a solid, fluid-impervious core, are generally more stable at elevated temperature than conventional porous supports. At elevated column temperature the viscosity of the mobile phase decreases with concomitant increase in solute diffusivity and improvement of sorption kinetics. From these considerations, it follows that columns packed with micropellicular stationary phases offer the possibility of significant improvements in the speed and column efficiency in the analysis of proteins, peptides and other biopolymers over those obtained with conventional porous stationary phases. In this paper, we describe selected examples for the use of micropellicular reversed phase... 

Analysis of sorption kinetics. During adsorption a concentration profile C(x,t) of protein is established in an unstirred layer separating the adsorbing surface, situated at x=0, from the buffer solution. It IS assumed that initially no protein is present in the system and that at time t=0 the bulk concentration of protein in the buffer is changed to a fixed value It is also assumed that the adsorption rate is proportional to the number of free binding sites and to the protein concentration at the surface. The rate of desorption is assumed to be proportional to the surface concentration. For this binding model one hast... 

Wall effects, or the adherence of material to the bare silica capillary wall, has been a difficult problem since the early days of HPCE, particularly for large molecules such as proteins. Small molecules can have, at most, one point of attachment to the wall and the kinetics of ad-sorption/desorption are rapid. Large molecules can have multiple points of attachment resulting in slow kinetics. Several solutions have been proposed, including the use of (a) extreme-pH buffers, (b) high-concentration buffers, (c) amine modifiers, (d) dynamically coated capillaries, and (e) treated or functionalized capillaries. 

Kinetics of Protein Sorption on Phospholipid Membranes Measured by Ellipsometry... 

Crank and Park (1968) reviewed experimental techniques for measuring diffusion of solutes through polymers, which generally apply to proteins as well as drug molecules. These techniques are based on two principles permeation of the protein through a membrane, and sorption/desorption kinetics for the protein/polymer system. 

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