A perspective on the characterization of colloids and macromolecules using asymmetrical flow field-flow fractionation

Asymmetrical flow field-flow fractionation (AF4) is rapidly becoming a technique of choice for the separation and characterization of complex materials. It is capable of fractionating samples over a wide size (∼2 nm to 50 μm in diameter) and molecular weight range (103–1010 g/mol). It offers gentle, low shear, low pressure separation conditions which are essential to preserve the structure and aggregation of fragile species. In this paper we illustrate a number of examples where AF4 plays central role in providing detailed and accurate characterization of polydisperse and complex colloidal and macromolecular materials such as proteins, polysaccharides, nanoparticles, and emulsion droplets.