|Molecule, particle, vesicle? - The new challenge for analytical separation technologies in polymer and protein characterisation
|Comprehensive Chromatography - The State of the Art
|Mr Paul Clarke
| Bassem Sabagh
Abstract Information :
The characterisation of polymers and proteins in solution for molecular weight and size/structure by size exclusion chromatography (SEC or GPC) is often restricted by the two requirements that the sample is fully dissolved in the mobile phase and has no interaction with the column packing material. More importantly, SEC cannot be used when the sample forms or contains large aggregates, complexes, particles or other supramolecular structures such as fibrils or vesicles. In these cases we must resort to batch light scattering techniques, most commonly DLS (dynamic light scattering) which by its nature yields little or no information about the size distribution or molecular weights and furthermore, may give misleading information due to the weighting effect on the data by larger species present.
This paper describes and presents a field-flow fractionation (FFF) separation technique that compliments SEC. It can separate polymers, proteins and particles in solution or suspension and can be coupled to DLS and MALS (multi-angle light scattering) to obtain accurate distribution information. We will show several application examples of how unique analytical data can be obtained from samples of polymers, proteins, particles and vesicles.