Hydrodynamic aspects of slurry packing processes in microcolumn liquid chromatography

A Stokesian dynamics computer simulation based method is presented for the estimation of the bed porosity of slurry-packed capillary liquid chromatography (LC) columns. A colloidally well-described reversed-phase stationary phase-slurry liquid suspension was used as a model system. The applied simulation method takes into account the velocity of the slurry and colloidal interaction forces, as well as inter-particle hydrodynamic interactions. The predicted bed porosities suggest that a lower slurry velocity leads to a denser packing structure due to the increased effect of colloidal repulsion effects. The results of the simulations were compared with the external porosity and chromatographic performance of capillary LC columns that were packed at different filtration and compaction pressures. However, the trends that were observed in the experimental results suggest that hydrodynamic packing parameters have no or little effect on the chromatographic performance of capillary LC columns. Within the experimental parameter window, the chromatographic performance and the column porosity were not influenced by the filtration and compaction pressure, nor by the duration of the compaction process.