TEM and SP-ICP-MS Analysis of the Release of Silver Nanoparticles from Decoration of Pastry

• Published in: Journal of agricultural and food chemistry Vol. 63; no. 13; pp. 3570 - 3578
• Main Authors: Verleysen, E, Van Doren, E, Waegeneers, N, De Temmerman, P.-J, Abi Daoud Francisco, M, Mast, J
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 08-04-2015
• Subjects: Food Additives - chemistry; Mass Spectrometry - methods; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Microscopy, Electron, Transmission; Particle Size; Silver - analysis; Silver - chemistry; X-Ray Diffraction; inductively coupled plasma mass spectrometry; energy dispersive X-ray spectroscopy; transmission electron microscopy; silver nanoparticles; image analysis; food matrix
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.5b00578

Metallic silver is an EU approved food additive referred to as E174. It is generally assumed that silver is only present in bulk form in the food chain. This work demonstrates that a simple treatment with water of “silver pearls”, meant for decoration of pastry, results in the release of a subfraction of silver nanoparticles. The number-based size and shape distributions of the single, aggregated, and/or agglomerated particles released from the silver pearls were determined by combining conventional bright-field TEM imaging with semiautomatic particle detection and analysis. In addition, the crystal structure of the particles was studied by electron diffraction and chemical information was obtained by combining HAADF-STEM imaging with EDX spectroscopy and mapping. The TEM results were confirmed by SP-ICP-MS. The representative Ag test nanomaterial NM-300K was used as a positive control to determine the uncertainty on the measurement of the size and shape of the particles.