Nano- and micro-particles in food and consumer products: the role of the Field Flow Fractionation techniques in their characterization

Nanomaterials (NMs) cover a broad range of materials of different chemical composition. Because of their diverse properties, they are used in a wide range of applications and products, such as cosmetic products (e.g. UV absorbers in sunscreens), food (enhanced flavour and texture, encapsulation of micronutrients), medical devices (diagnostics, drug delivery), medicinal products. The recent abundant use of NMs has placed, however, the accent on their potential risk, since nanoparticles, with their sizes between 1-100 nm, might interact with membrane cells of any living beings (plants, animals, humans). Consequently, legislators who are dealing with health and consumer protection have asked to the scientific community to implement or set-up new analytical methods able to detect and characterize the nanoparticles contained especially in food and consumer products to evaluate the risk on a solid definition of NMs. This work will illustrate, as the Field Flow Fractionation techniques (FFF), might be useful separation instruments to sort complex samples and to determine the average sizes and the particle size distribution of nano- and micro-particles. FFF techniques are often coupled online with a series of detectors such as UV-vis, refractive index, fluorescence, scattering detectors (DLS or MALS), ICP-MS, ICP-OES, GFAAS, whose choice depends on the practical application. Examples of SiO2, silver, and ZnO separations will be presented in the light of the characterization suggested by the European Commission