Absolute characterization of colloids by field-flow fractionation

The fundamental aspects of Field-Flow Fractionation (FFF) techniques in their features of being absolute characterization techniques for colloids - particles, macromolecules and molecular assemblies - are reviewed. The different physico chemical properties which can be determined, are classified as key, primary or secondary quantities according to whether they are obtained respectively from a single FFF measurement, from additional informations and/or measurements about the analyte or from differential measurements about different analytes using a given FFF method. Emphasis is given to the stepwise hypotheses required in determining different physicochemical properties. The different possible procedures for obtaining primary quantities for both monodisperse or quasi-monodisperse species and distributions of primary quantities for polydisperse species are described. Advantages and drawbacks are reported.