Titanium dioxide nanoparticles in food: comparison of detection by triple-quadrupole and high-resolution ICP-MS in single-particle mode

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2021-04, Vol.23 (4), Article 102
• Main Authors: Noireaux, Johanna, López-Sanz, Sara, Vidmar, Janja, Correia, Manuel, Devoille, Laurent, Fisicaro, Paola, Loeschner, Katrin
• Format: Article
• Language: English
• Subjects: Calcium; Characterization and Evaluation of Materials; Chemistry and Materials Science; Chewing gum; Confectionery; Dwell time; Food additives; Fractionation; High resolution; Inductively coupled plasma mass spectrometry; Inorganic Chemistry; Lasers; Light scattering; Mass spectrometry; Mass spectroscopy; Materials Science; Mean; Microscopy; Nanoparticles; Nanotechnology; Optical Devices; Optics; Particle size; Photonics; Physical Chemistry; Quadrupoles; Research Paper; Scanning electron microscopy; Titanium; Titanium dioxide
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-021-05198-1

We used triple-quadrupole and high-resolution inductively coupled plasma-mass spectrometry (ICP-MS) in single-particle mode to characterize the food additive E171 (titanium dioxide, TiO 2 ) in chewing gum, chocolate candy, and cake decoration in the same sample extracts. Then, we spiked TiO 2 particles (with similar characteristics as E171) to milk as an example of a calcium-rich matrix. The obtained particle size distributions with both techniques were highly similar in terms of shape and median and mean diameters. Median diameters were in the range of 123 to 209 nm and mean diameters from 146 to 223 nm. In addition, they were in agreement with results obtained by scanning electron microscopy and asymmetric flow field-flow fractionation coupled to multi-angle light scattering and ICP-MS. Repeatable determination of number-based particle size distributions was possible with both ICP-MS techniques even in a calcium-rich matrix showing that both instruments were similarly efficient in resolving the Ca interferences. The combination of spICP-MS with microscopy and TiO 2 recovery allowed validating the methods and identifying the presence of aggregated/agglomerated particles in one sample. For the TiO 2 powder and the two remaining food products, recoveries were higher than 60%. Both instruments are fit for purpose even if the analyses were performed with differences in detector mode, dwell times, and calculation tools. This shows that both techniques may be used as long as operating conditions are optimized and applicability range is defined.