title: Production of reference materials for the detection and size determination of silica nanoparticles in tomato soup.
abstract: A set of four reference materials for the detection and quantification of silica nanoparticles (NPs) in food was produced as a proof of principle exercise. Neat silica suspensions were ampouled, tested for homogeneity and stability, and characterized for total silica content as well as particle diameter by dynamic light scattering (DLS), electron microscopy (EM), gas-phase electrophoretic molecular mobility analysis (GEMMA), and field-flow fractionation coupled with an inductively coupled mass spectrometer (FFF-ICPMS). Tomato soup was prepared from ingredients free of engineered nanoparticles and was spiked at two concentration levels with the silica NP suspension. Homogeneity of these materials was found sufficient to act as reference materials and the materials are sufficiently stable to allow long-term storage and distribution at ambient temperature, providing proof of principle of the feasibility of producing liquid food reference materials for the detection of nanoparticles. The spiked soups were characterized for particle diameter by EM and FFF-ICPMS (one material only), as well as for the total silica content. Although questions regarding the trueness of the results from EM and FFF-ICPMS procedures remain, the data obtained indicate that even assigning values should eventually be feasible. The materials can therefore be regarded as the first step towards certified reference materials for silica nanoparticles in a food matrix.
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440, Geel, Belgium.
authors.forename: Ringo
authors.initials: R
authors.lastname: Grombe
authors.forename: Jean
authors.initials: J
authors.lastname: Charoud-Got
authors.forename: Håkan
authors.initials: H
authors.lastname: Emteborg
authors.forename: Thomas P J
authors.initials: TP
authors.lastname: Linsinger
authors.forename: John
authors.initials: J
authors.lastname: Seghers
authors.forename: Stephan
authors.initials: S
authors.lastname: Wagner
authors.forename: Frank
authors.initials: F
authors.lastname: von der Kammer
authors.forename: Thilo
authors.initials: T
authors.lastname: Hofmann
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Dudkiewicz
authors.forename: Meritxell
authors.initials: M
authors.lastname: Llinas
authors.forename: Conxita
authors.initials: C
authors.lastname: Solans
authors.forename: Angela
authors.initials: A
authors.lastname: Lehner
authors.forename: Günter
authors.initials: G
authors.lastname: Allmaier
mesh_terms: D005506:Food Contamination / Q000032:analysis*; D018551:Solanum lycopersicum / Q000737:chemistry*; D013058:Mass Spectrometry; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012542:Scattering, Radiation; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D012822:Silicon Dioxide