Natural colloid characterization using flow-field-flow-fractionation followed by multi-detector analysis

A design for a flow-field-flow-fractionation with UV/VIS-, fluorescence- and laser-light-scattering-detectors is presented and tested with extracts from a humus rich horizon of a gleyic podzol. It is tested to show how the system can retrieve relevant information about changes in the constitution of the colloid samples. The main objective is the investigation of colloid alteration during processes provoked by main geochemical driving forces (e.g. pH or ionic strength), in this case changes of redox potential. Therefore fluorescence- and UV/VIS-fractograms are taken at different wavelengths and compared. Particle diameters of natural colloids are calculated from laser-light-scattering data and compared with reference standards.