Molecule, Particle, Vesicle? – The New Challenge for Analytical Separation Technologies in Polymer and Protein Characterisation

Gerhard Heinzmann, Postnova Analytics GmbH, Landsberg, Germany

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.

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Short Biography of Presenting Author

Paul is a graduate of the UK Royal Society of Chemistry and has over 30 years practical experience in the separation and characterisation of macromolecules and particles by SEC, FFF, light scattering and viscometry.  He has spent most of that time in the analytical instruments industry working for long periods with Viscotek Corporation (USA), Malvern Instruments (UK) and now currently with Postnova Analytics (Germany) where he is the UK Managing Director. 

His background and experience covers all aspects of the separation and characterisation of polymers, proteins and particles using a wide variety of techniques with an emphasis on multi-detection, flow-based techniques to yield the maximum information per analysis.