Nanotechnologies — Methods for sample preparation for particle size and shape measurements by electron microscopy methods and atomic force microscopy

This document gives guidance on reliable and reproducible sample preparation for particle size and shape measurement by electron microscopy (EM) or atomic force microscopy (AFM). This document is applicable, but not limited to nanoparticles in samples from suspensions, aerosols or powders. The methods include preparation on flat substrates, grids, or through planarization to facilitate quantitative analysis based on EM or AFM imaging. To ensure consistency and comparability of results, the document also provides criteria for selecting the most suitable preparation techniques and defining key procedural parameters. Additionally, it outlines standardized reporting requirements to enhance reproducibility and support a broad applicability of these methods across different laboratory facilities.