Effect of pressure drop model implemented for description of pressure drop on chromatographic monolith on estimated adsorbed layer thickness

- Determination of layer thickness formed by adsorbed macromolecules from a pressure drop data.
- Extension of methodology to four pressure drop models for beds of high porosity.
- Proposed methodology provides accurate results within 10% RSD for a wide range of porosity.
- Thickness in nanometer scale can be estimated covering range from small proteins up to large viruses.

Chromatographic monoliths are successfully implemented in many areas of separation science. Recently it was demonstrated that they can also be used for estimation of layer thickness formed by molecules adsorbed on surface of pores when pressure drop can be described by Kozeny-Carman model. This assumption is however questionable due to variety of monolith microstructures and high monolith porosity being regularly above 0.6. In this work proposed approach is extended to other pressure drop models for porosities between 0.60 and 0.95. It was demonstrated that estimated values of layer thickness with around 10% accuracy can be obtained in a broad porosity range regardless implemented pressure drop model. Therefore, no detailed information about monolith microstructure is needed to get reasonable estimation of thickness formed by adsorbed molecules.