Quantitative analysis of engineered nanoparticles in food and environment

Autor(en)

Frank von der Kammer, Stephan Wagner, Samuel Legros, Boris Meisterjahn, Erik H. Larsen, Katrin Loeschner, Jana Navratilova, Thilo Hofmann

Abstrakt

Consumer products containing engineered nanoparticles (ENPs) are already on the market. During the production, use and disposal/recycling of these products ENPs might expose consumers and may be released into the environment. For regulation enforcement and risk assessment regarding, 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 isolated particles have to be stabilized and pre-concentrated prior to further particle characterization. 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 coupled to specific detectors like multi-angle light scattering, UV-VIS spectrometry and ICP-MS for 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. This can be achieved by specific approaches which are carefully adapted to the properties of particle (SiO2 and Ag) and matrix. Colloidal extraction, acidic, alkaline and enzymatic attack was investigated in detail. The effect of the sample preparation on particle size distribution and elemental mass recovery was studied and optimized.
To establish the required 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 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. Using this systematic and stepwise approach we arrived at optimized run conditions for the FFF and for the specific particle detection (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 complex food and soil/sewage sludge matrices. Examples of silica ENPs in tomato soup and silver-ENPs chicken meat and soil/sewage sludge will be presented. The results show that the tested ENPs can be analyzed in complex matrices as soup or meat with good precision and mass recovery (> 80%). We could demonstrate that with our systematic approach optimized analytical tools for ENP analysis and characterization in complex matrices as food and environmental media can be developed. These methods are considered to be compulsory for future tasks including enforcement of future regulations, risk assessment and toxicology.

Organisation(en)

Externe Organisation(en)

French Alternative Energies and Atomic Energy Commission (CEA), Technical University of Denmark (DTU)

Publikationsdatum

2012

ÖFOS 2012

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

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/4105f9c9-c3d0-4d32-842c-e2b95939f9c0