Activity: Talks and presentations › Talks and presentations in private or public companies and organisations
Labelling for the content of engineered nanomaterials as ingredients in food is mandatory in the European Union since December 2014 in accordance with Regulation 169/2011. Enforcing proper labelling of “nano” poses several analytical challenges. This includes challenges in relation to sample preparation, the limitations of existing analytical techniques and the lack of validated studies and reference materials. In this context, we investigated food samples containing the food additive E171. E171 is titanium dioxide (TiO2) and used as a white pigment. This effect is achieved when the particles are not in the nanosize. However, due to the broad size distribution of the powders a certain fraction of NPs can be present. Among the currently most widespread techniques for the detection and characterization of NPs in food is inductively coupled plasma-mass spectrometry (ICP-MS) used in single particle mode (spICP-MS). We used the Agilent 8900 ICP-QQQ-MS in no gas and H2/O2 mode (Q1: 48, Q2: 64) to study chewing gum, chocolate candy and cake frosting (inscription). Further, we spiked reference TiO2 NPs to milk as an example of a calcium-rich matrix. Repeatable determination of number-based particle size distributions was possible with a minimum detectable particle size of ~30 nm. The median particle diameters were in the range of 130 to 200 nm. Particle mass concentrations were in the mg/g range. The relatively easy implementation of spICP-MS in state-of-the-art ICP-MS instruments (which can be otherwise used for metal analysis and speciation) makes it a promising technique for routine analysis despite some analytical limitations.