Abstract

Hydrocolloids are suspected as carriers of pollutants in water, permitting an accelerated transport in aquatic systems. Especially heavy metals and residues of organic contaminants can be bound to colloidal matter by a variety of functional groups. As the particulate transport depends on size and material of the particles, a characterization of colloidal systems in terms of number density, size distribution and chemical composition is of increasing interest for migration studies of environmentally relevant substances. Field flow fractionation (FFF) covers a class of generic chromatographic separation methods for separation of particles with high resolution and a dynamic range up to five orders of magnitude. FFF is a one-phase fractionation technique in which a flow field, applied perpendicularly to a particle-containing flow, forces dissimilar particles to partition among flow lines of different velocity. Like all chromatographic techniques, FFF provides no quantitative information and has to be combined with a suitable particle detector. Since only light-scattering detectors are normally employed, the detection is restricted to particle diameters above 200 nm.

© 1996 IEEE