The European Commission has recently recommended the development of a definition of nanomaterials (NM), which could be used as a reference to determine whether an unknown material can be considered as a nanomaterial. The NanoDefine project will explicitly address this question.
Based on a comprehensive evaluation of existing methodologies and a rigorous intra-lab and inter-lab comparison, validated measurement methods and instruments will be developed. These tools will be robust, readily implementable and cost-effective. Also, they will enable reliable measurement of the particle size in the 1-100nm range.
Nanotechnology is a key enabling technology. One challenge consists in the development of methods that reliably identify, characterise and quantify nanomaterials (NM) both as substance and in various products and matrices.
One major outcome of this project is the establishment of an integrated tiered approach including validated rapid screening methods and validated in depth methods, with a user manual to guide end-users, such as manufacturers, regulatory bodies and contract laboratories to implement the developed methodology.
Sciensano contributes to the development of sample preparation, dispersion & sampling methods for nanomaterials and to software development and validation for automated electron microscopy (EM) image analysis of NM.
Sample preparation, dispersion & sampling methods
The aim is to identify representative sampling strategies and to develop and optimise methods to disperse NM in such a way that the resulting dispersions of nanoparticles from substances and products are stable and contain a maximum of mainly primary constituent particles. EM will be used to distinguish between large primary constituent particles and non-dispersable aggregates.
Software development and validation for automated EM image analysis
The aim is to aid in the development of an off-line method for automated image analysis of particulate materials imaged by electron microscopy. The method allows to automatically determine the distributions of the characteristic properties of primary particles in aggregates and agglomerates, or present as single particles, from EM images. This application is specifically designed in the scope of implementing the EC-definition of a nanomaterial. The median value of the number-based distribution of the minimal external dimension of the primary particles is assessed.
The developed image analysis method is validated according to international standards (i.a. IUPAC) for single-laboratory validation.