How to develop a quantitative and validated method for the analysis of engineered nanoparticles in a complex food matrix

Autor(en)

Stephan Wagner, Frank von der Kammer, Samuel Legros, Thilo Hofmann

Abstrakt

Food products containing engineered nanoparticles (ENPs) or food that is in contact to nanoparticle containing materials are already on the market. Regarding regulation enforcement and risk assessment, validated quantitative methods for ENP analysis in a wide variety of matrices are needed. These methods are not available so far.
The analytical strategy to be adopted depends strongly on the information requested, the type of the ENPs and the nature of the matrix. E.g. samples with a complex matrix require in most cases a pre-treatment in preparation of analysis in order to isolate the ENPs from the matrix. The following analysis aims at the determination of particle size distribution and selective element & mass concentration.
Field Flow Fractionation (FFF) is one of the most promising analytical techniques for these tasks. FFF is an analytical particle sizing and separation technique which can be coupled to specific detectors like multi-angle light scattering, UV-VIS spectrometry and ICP-MS for independent quantification of particle size distribution as well as size and element specific mass concentrations.
The sample preparation for FFF must provide the isolation of ENPs from the matrices or transform the matrix into a form suitable for FFF separation. Colloidal extraction, acidic, alkaline and enzymatic attack as sample preparation techniques were investigated in detail focusing on the effect on particle size distribution and elemental mass recovery.
To establish the required precise and robust FFF methods for analyzing the isolated ENPs a systematic approach to thoroughly optimize and validate FFF for certain combinations of ENPs and sample matrix has been adopted. Critical system parameters like cross flow rate, carrier composition, membrane type, channel height and injection volume, mass and focusing procedure have been investigated for their influence on the accuracy and overall performance of FFF. Similar systematic studies were performed for the specific particle detection following separation as e.g. by light scattering and ICP-MS. The optimization schemes aimed at maximum recovery, lowest possible influence on particle size distribution, minimum alteration of the original ENPs during analytical procedure and practical applicability of the method (e.g. analysis time).
Using these analytical techniques we systematically developed methods to detect and quantify ENPs in a complex food matrix. As example silica ENPs in tomato soup were chosen. For quality control an in-house validation and comparison between different laboratories were performed.
The results show that the tested ENPs can be analyzed in complex matrices as tomato soup with good precision and mass recovery (> 80%). We could demonstrate that with our systematic approach with a subsequent validation optimized analytical tools for ENP analysis and characterization in complex matrices as food can be developed.

Organisation(en)

Externe Organisation(en)

French Alternative Energies and Atomic Energy Commission (CEA)

Anzahl der Seiten

1

Publikationsdatum

2013

ÖFOS 2012

210006 Nanotechnologie, 104002 Analytische Chemie, 104023 Umweltchemie, 105904 Umweltforschung

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/7c951932-0542-4bbd-ae25-2dc4887ad360