An Observation of a Field-Flow Fractionation Effect with Polystyrene Samples

Field-flow fractionation (FFF) is a proposed separation method in which some kind of lateral field is coupled with nonuniform axial flow to induce differential migration (1). Fractionation is here illustrated by applying a temperature drop laterally across a narrow tube within which a mixture is flowing. In this case thermal diffusion is responsible for lateral enrichment. This variation of the general concept may be termed thermal field-flow fractionation.