Characterization of pore size distribution of packing materials used in perfusion chromatography using a network model

A network model is used to represent the porous structure existing in a column packed with perfusive stationary phase. By matching model simulations with experimental mercury intrusion data, characteristics of the pore size distribution (PSD) of perfusive particles can be calculated quantitatively. It was found that the distribution is bimodal, consisting of an interconnected porous structure of macropores (pore diameters of the order of 1000 Angstrom) and micropores (pore diameters of the order of 100 Angstrom). Two different types of perfusive packings (POROS I and II) were compared in terms of capacity and throughput capabilities with respect to their PSD. The sensitivity and validity of the model was corroborated by simulating intrusion experiments on blends of the perfusive packings. The simulated results compared very well with the experimental data. The network model was used to elucidate pertinent parameters using perfusive packings such as surface area accessibility of various proteins and size-exclusion chromatography of polystyrene molecules. The agreement between experimental data and model predictions are excellent in both studies.