Production of reference materials for the detection and size determination of silica nanoparticles in tomato soup
- 776 Downloads
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.
KeywordsEngineered nanoparticles Colloidal silica Reference material production
The work leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement no. 245162. The authors thank Mrs. Meeus (EC JRC IRMM) for conducting the microbiology tests.
- 1.Recommendation 2011/696/EU of the European Commission on the definition of nanomaterialGoogle Scholar
- 2.Regulation 1169/2011 of the European Parliament and of the council on the provision of food information to consumersGoogle Scholar
- 4.Schlag S, Suresh B, Yoneyama M, Yang V (2010) Nanoscale Chemicals and Materials, Report by SRI Consulting, 2010Google Scholar
- 5.Plachutta E, Wagner C: Die gute Kueche, Orac, Vienna, Austria, 1993, ISBN 3701503109; p160 “Rindsknochensuppe” and p. 170 “Tomatensuppe”Google Scholar
- 8.Matissek M, Steiner G (2006) Lebensmittelanalytik, Grundzüge, Methoden, Anwendungen, 3rd edn. Springer Verlag, Berlin HeidelbergGoogle Scholar
- 9.Wagner S, v.d. Kammer F, Legros S, Larsen EH, Loeschner K, Navratilova J, Hofmann T Sample preparation for detection of silica NPs in soup by AF4-ICP-MS (manuscript in preparation)Google Scholar
- 11.Wohlecke H, Lerche D, Detloff T, Franks K, Kestens V, Roebben G (2013) In-situ determination of the effective particle density of suspended colloidal silica particles by means of analytical centrifugation, Poster at Partec 2013, Nuremberg, April 23-25 2013. Abstract available via http://www.partec.info/en/review/review2013/
- 16.ISO Guide 35 (2006) Reference materials — General and statistical principles for certification, International Organization for Standardization, Geneva, SwitzerlandGoogle Scholar
- 17.ISO 13321(1996) Particle size analysis -- Photon correlation spectroscopy, International Organization for Standardization, Geneva, SwitzerlandGoogle Scholar
- 18.Wagner S, von der Kammer F (2013) Final report of the FP7 project “NanoLyse Nanoparticles in Food: Analytical methods for detection and characterisation”, Collaborative project 245162. A peer-reviewed publication on the FFF-ICPMS work on the method development and validation for silica NPs in soup is planned for 2014Google Scholar