Size fractionation of nanoparticles and colloids using field flow fractionation (FFF)

Aqueous suspensions of particles in the size range from about 1 nm to 1 µm can be separated according to size in a thin channel via a flow field and analysed online with ICP-MS regarding their elemental composition. This enables for example the quantification of the particle bound fraction of nutrients such as phosphorus species in fresh water samples and soil extracts, which significantly contribute to nutrient transport and storage.

The detection of low particle bound phosphorus concentrations was developed in cooperation with IBG-3 (Agrosphere) and the method was extended to parallel monitoring of organic particles and surface modifications via the carbon content using ICP-MS. The development of a special interface for hyphenation of FFF to ICP-MS enabled also the quantification of the dissolved elemental fraction in addition to the routinely monitored particulate fraction.

Contact: Dr. Volker Nischwitz