In short
Size is an important characteristic to determine nanoparticles’ toxicity, mobility and sorption capacity (i.e. the capacity to stick in- or onto other items). Iron oxyhydroxides are probably the most important natural dispersed particles in the environment and may occur as nano-sized minerals or aggregates thereof. They play a vital role in the transport of contaminants and nutrients in aquatic and soil environments. Measuring the size distribution of these iron nanoparticles accurately is a prerequisite in order to understand their fate in the environment, hence there is a need for reliable methods to detect and characterize these materials. The goal of this study is to compare and validate different methods for nanoparticle size determination.
Project description
Nanoparticle size is an important characteristic to etermine nanoparticles’ toxicity, mobility and sorption capacity. Iron (Fe) oxyhydroxides are probably the most important natural colloids in the environment and may occur as nano-sized minerals or aggregates thereof. They play a vital role in the transport of contaminants and nutrients in aquatic and soil environments. Measuring the size distribution of these iron nanoparticles accurately is a prerequisite in order to understand their fate in the environment.
Flow field flow fractionation (FFF) is a fractionation technique that separates particles based on their hydrodynamic size and is now commonly adopted for characterizing nanoparticles. Its use for environmental or synthetic Fe-oxyhydroxide nanoparticles is, however, limited. In recent years, single particle ICP-MS (SP-ICP-MS) has been added to the list of methods for size characterization of nanoparticles. Single particle ICP-MS measures the mass of individual inorganic particles, from which a diameter can be calculated assuming a certain shape of the particles (e.g. mass equivalent spherical diameter). The general goal of this study is to apply a FFF-UV-ICP-MS system at KU Leuven to a range of natural and synthetic Fe-oxyhydroxide nanoparticles and to compare that to the SP-ICP-MS method at Sciensano.
This study is therefore an additional validation study for SP-ICP-MS and a validation of the developed FFF-UV-ICP-MS method and contributes to a better understanding of the accuracy of FFF for measuring iron nanoparticle size distributions. In addition, both methods will be compared with other methods available at KU Leuven and Sciensano such as electron microscopy.