This paper presents the influence of the silica pore size on the separation, efficiency and capacity of a separation using a number of standard compounds. The study uses a prep to process material, SepTech, which uses ultra pure silica as the base particle and a bonding chemistry to give a high carbon load C18 material. Two pore sizes, a 60Å (ST60 10-C18) and a 150Å (ST150 10- C18) were used. The results show that the silica pore size has a large impact on the separation efficiency, resolution and capacity.
This document evaluates the impact of silica pore size on the efficiency, resolution, and loading capacity of reversed-phase HPLC separations. It compares two SepTech stationary phases, ST60 10-C18 (60A pore size) and ST150 10-C18 (150A pore size), using standard compounds and peptide mixtures.
The study demonstrates that while small pore materials offer high surface area, larger molecules like peptides cannot access the internal pore structure effectively. Consequently, larger pore sizes are required for efficient separation and higher capacity when dealing with larger natural compounds and peptides.
| Nominal Pore Size (ST60) | 60 A |
|---|---|
| Carbon Load (ST60) | 25 % |
| Operating pH Range | 1.5-10 |
The larger pore size material, SepTech ST150 10-C18, is required for viable peptide separations because the 60A pore size is too small for efficient diffusion.
Resolution is improved by using the larger pore size material, as it allows better access to the internal surface area for larger solutes.
The pore size of SepTech ST60 10-C18 is too small for peptides to access the internal pore surface area, resulting in reduced capacity.