Methods to Measure the Particle Size Distribution of Nanoparticles in Complex Matrices

L. Calzolai, D. Gilliland, F. Rossi
Joint Research Center. European Commission, IT

Keywords: nanomaterials, particle size distribution, legislation

Summary:

Nanoparticles are already used in several consumer products including food, food packaging and cosmetics and their detection and measurement represent a particularly difficult challenge. The European Commission has published in October 2011 its recommendation on the definition of nanomaterial. This definition calls for the measurement of the number based particle size distribution in the 1-100 nm size range of all the primary particles present in the sample independently of whether they are in a free, unbound state or as part of an aggregate/agglomerate. This definition does present great technical challenges for developing measuring methods. In this presentation we will illustrate the development of techniques for the size measurement of nanoparticles when addressing this new definition of nanomaterials. These new methods are based on the combination of size separation techniques, such as flow field flow fractionation, with identification and quantification techniques, such as ICP-MS. The problems to be overcome in measuring nanoparticles in food and consumer products will be illustrated with some practical examples, including interlaboratory performance studies organized by JRC.