title: Uncertainties of size measurements in electron microscopy characterization of nanomaterials in foods.
abstract: Electron microscopy is a recognized standard tool for nanomaterial characterization, and recommended by the European Food Safety Authority for the size measurement of nanomaterials in food. Despite this, little data have been published assessing the reliability of the method, especially for size measurement of nanomaterials characterized by a broad size distribution and/or added to food matrices. This study is a thorough investigation of the measurement uncertainty when applying electron microscopy for size measurement of engineered nanomaterials in foods. Our results show that the number of measured particles was only a minor source of measurement uncertainty for nanomaterials in food, compared to the combined influence of sampling, sample preparation prior to imaging and the image analysis. The main conclusion is that to improve the measurement reliability, care should be taken to consider replications and matrix removal prior to sample preparation.
authors.affiliation: The Food and Environment Research Agency, Sand Hutton, York Y041 1LZ, UK; The University of York, Heslington, York YO10 5DD, UK. Electronic address: agnieszkaidudkiewicz@gmail.com.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Dudkiewicz
authors.affiliation: The University of York, Heslington, York YO10 5DD, UK.
authors.forename: Alistair B A
authors.initials: AB
authors.lastname: Boxall
authors.affiliation: The Food and Environment Research Agency, Sand Hutton, York Y041 1LZ, UK.
authors.forename: Qasim
authors.initials: Q
authors.lastname: Chaudhry
authors.affiliation: Deptartment of Micro and Nanotechnology, Technical University of Denmark, Ørsteds Plads 345E, 2800 Kongens Lyngby, Denmark.
authors.forename: Kristian
authors.initials: K
authors.lastname: Mølhave
authors.affiliation: The Food and Environment Research Agency, Sand Hutton, York Y041 1LZ, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Tiede
authors.affiliation: Department of Geoinformatics - Z_GIS, University of Salzburg, Schillerstr. 30, 5020 Salzburg, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Hofmann
authors.affiliation: Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium.
authors.forename: Thomas P J
authors.initials: TP
authors.lastname: Linsinger
mesh_terms: D005504:Food Analysis / Q000379:methods*; D008854:Microscopy, Electron / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry*; D015203:Reproducibility of Results
keywords: Electron microscopy; Food; Measurement uncertainty; Minimal sample intake; Nanomaterials