Alternative bioseparation operations: life beyond packed-bed chromatography.

Affinity membrane chromatography for the analysis and purification of proteins

Polymethacrylate monoliths for preparative and industrial separation of biomolecular assemblies.

Monoliths as stationary phases for separation of proteins and polynucleotides and enzymatic conversion.

Bioprocess challenges to the isolation and purification of bioactive peptides

The characterization of CIM® DEAE monolithic columns in terms of dynamic binding capacity is presented in this paper. Breakthrough experiments were performed for capacity determination. Bovine serum albumin (BSA) was used as a model protein. It is shown that CIM® monolithic columns have good batch-to-batch reproducibility as well as long-term stability. The experiments performed under different linear velocities demonstrated that the dynamic capacity is unaffected at least up to a linear velocity of 2450 cm/h. Furthermore, the breakthrough curve slope is constant, indicating that the capacity would remain constant at even higher linear velocities. The adsorption isotherm of BSA dissolved in 20 mM Tris-HCl buffer shows a constant capacity of around 30 mg/mL of support down to a concentration of 20 μg/mL. The capacity is substantially influenced by the ionic strength; however, 20% of the maximal capacity is still preserved at 0.3 M NaCl.

Dynamic Capacity Studies of CIM (Convective Interaction Media)® Monolithic Columns

Pressure drop in CIM disk monolithic columns.

Monolithic stationary phases are becoming more and more important in the field of liquid chromatography, because they enable extremely fast separations. Methacrylate-based monoliths are produced via a free-radical bulk polymerization of glycidyl methacrylate and ethylene dimethacrylate using a benzoyl peroxide as an initiator. Preparation of large monoliths represents a big problem because of the heat release during the polymerization, which consequently leads to the distortion of the structure. A closer investigation of the polymerization, using differential scanning calorimetry, was performed in order to determine global kinetic parameters. A multiple heating rate method, based on the work of Ozawa, Flynn, and Wall, was applied for estimation of the values of the apparent activation energy, preexponential factor, and reaction order. Global polymerization kinetics is of first order with A = 1.681 × 10 9 s -1 and E a,app = 81.5 kJ/mol, where the heat of polymerization is approximately 190 J/g. In addition, the influence of air and nitrogen atmosphere on polymerization is presented.

Kinetic model of a methacrylate-based monolith polymerization

Temperature influence on the dynamic binding capacity of a monolithic ion-exchange column.

Monolithic stationary phases are becoming increasingly important in the field of liquid chromatography. Methacrylate-based monoliths are produced via free-radical bulk polymerization. The preparation of large-volume monoliths is a major problem because the intensive heat released during polymerization causes distortion of the porous monolithic structure. This work presents experimental measurements of temperature distributions during polymerization in moulds of different sizes and at various experimental conditions. A mathematical model for the prediction of temporal and spatial temperature distribution during the polymerization of methacrylate-based monolithic columns is introduced. The polymerization is described by an unsteady-state heat conduction equation with the generation of heat related to the general kinetics of polymerization. Predictions from the mathematical model are in good agreement with the experimental measurements at different experimental conditions. A method for construction of large-volume monolithic columns is presented and an attempt is made to adopt the developed mathematical model in annular geometry. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2326–2334, 2003

Igor Mihelič

Papers

Dynamic Capacity Studies of CIM (Convective Interaction Media)® Monolithic Columns

Pressure drop in CIM disk monolithic columns.

Kinetic model of a methacrylate-based monolith polymerization

Temperature influence on the dynamic binding capacity of a monolithic ion-exchange column.

Temperature distribution effects during polymerization of methacrylate‐based monoliths