Journal article
Prenormative verification and validation of a protocol for measuring magnetite–maghemite ratios in magnetic nanoparticles
Metrologia, Vol.59(1), p.15001
12/03/2021
DOI: 10.1088/1681-7575/ac36b6
Abstract
An important step in establishing any new metrological method is a prenormative interlaboratory study, designed to verify and validate the method against its stated aims. Here, the 57Fe Mössbauer spectrometric 'centre of gravity' (COG) method was tested as a means of quantifying the magnetite/maghemite (Fe3O4/γ-Fe2O3) composition ratio in biphasic magnetic nanoparticles. The study involved seven laboratories across Europe and North and South America, and six samples—a verification set of three microcrystalline mixtures of known composition, and a validation set of three nanoparticle samples of unknown composition. The spectra were analysed by each participant using in-house fitting packages, and ex post facto by a single operator using an independent package. Repeatability analysis was performed using Mandel's h statistic and modified Youden plots. It is shown that almost all (83/84) of the Mandel h statistic values fall within the 0.5% significance level, with the one exception being borderline. Youden-based pairwise analysis indicates the dominance of random uncertainties; and in almost all cases the data analysis phase is only a minor contributor to the overall measurement uncertainty. It is concluded that the COG method is a robust and promising candidate for its intended purpose.
Details
- Title: Subtitle
- Prenormative verification and validation of a protocol for measuring magnetite–maghemite ratios in magnetic nanoparticles
- Creators
- Lara K Bogart - University College LondonJeppe Fock - APS (Czechia)Geraldo M da Costa - Universidade Federal de Ouro PretoKerstin Witte - INP Leibniz-Institut für Plasmaforschung und Technologie , Felix-Hausdorff-Straße 2, 17489 Greifswald, GermanyJean-Marc Greneche - Institut des Molécules et Matériaux du MansJan Zukrowski - AGH University of KrakowMarcin Sikora - AGH University of KrakowDrew E Latta - University of IowaMichelle M Scherer - University of IowaMikkel Fougt Hansen - Technical University of DenmarkCathrine Frandsen - Technical University of DenmarkQuentin A Pankhurst - University College London
- Resource Type
- Journal article
- Publication Details
- Metrologia, Vol.59(1), p.15001
- DOI
- 10.1088/1681-7575/ac36b6
- ISSN
- 0026-1394
- eISSN
- 1681-7575
- Publisher
- IOP Publishing
- Number of pages
- 10
- Grant note
- 2014/14/E/ST3/00026 / National Science Center of Poland 604448 / FP7 Nanosciences, Nanotechnologies, Materials and new Production Technologies (https://doi.org/10.13039/100011263)
- Language
- English
- Date published
- 12/03/2021
- Academic Unit
- Civil and Environmental Engineering; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984202245402771
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