Detection and Characterization of Nanoparticles in Food and Biological Materials

With the increasing use of nanotechnology in food and consumer products, there is a need for reliable detection and characterization methods for nanoparticles (NPs) in complex matrices. NPs often interact with each other or with their surroundings leading to aggregation, adhesion to surfaces or dissolution in dispersion solvents. Accurate and precise characterization of metrics such as size, shape, particle mass and number concentration therefore remains a challenging analytical task. Asymmetric flow field flow fractionation (AF4) hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) is a powerful technique for the detection and characterization of inorganic NPs in complex matrices. In order to acquire accurate data the AF4 separation method and settings must be optimized for each new sample matrix and analyte NP combination. Furthermore, additional information obtained by single particle (sp) ICP-MS analysis of collected fractions or an imaging method such as transmission electron microscopy (TEM) are necessary for trouble shooting and for independent verification of results. spICP-MS as stand-alone technique is a powerful screening method for many inorganic NPs. A number of examples where AF4-ICP-MS and single particle ICP-MS were applied for the detection and characterization of NPs in food and biological matrices will be presented including: • Silver NPs in chicken meat • Silicon dioxide NPs in tomato soup • Aluminum-containing NPs in noodles • Gold NPs in cells