BAM Federal Institute for Materials Research and Testing 2 articles published in JoVE Chemistry Preparation of Nanoparticles for ToF-SIMS and XPS Analysis Francesca Bennet1, Anja Müller1, Jörg Radnik1, Yves Hachenberger2, Harald Jungnickel2, Peter Laux2, Andreas Luch2, Jutta Tentschert2 1Division of Surface Analysis and Interfacial Chemistry, Federal Institute for Material Research and Testing (BAM), 2Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR) A number of different procedures for preparing nanoparticles for surface analysis are presented (drop casting, spin coating, deposition from powders, and cryofixation). We discuss the challenges, opportunities, and possible applications of each method, particularly regarding the changes in the surface properties caused by the different preparation methods. Environment Dispersion of Nanomaterials in Aqueous Media: Towards Protocol Optimization Inder Kaur1, Laura-Jayne Ellis1, Isabella Romer1, Ratna Tantra2, Marie Carriere3,4, Soline Allard5, Martine Mayne-L'Hermite5, Caterina Minelli6, Wolfgang Unger7, Annegret Potthoff8, Steffi Rades7, Eugenia Valsami-Jones1 1School of Geography, Earth and Environmental Sciences, University of Birmingham, 2Analytical Science, National Physical Laboratory, 3INAC-LCIB, Université Grenoble Alpes, 4CEA, INAC-SyMMES, 5NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 6Chemical, Medical and Environmental Science, National Physical Laboratory, 7BAM Division 6.1 'Surface Analysis and Interfacial Chemistry', BAM Federal Institute for Materials Research and Testing, 8Fraunhofer Institute for Ceramic Technologies and Systems Here, we present a step-wise protocol for the dispersion of nanomaterials in aqueous media with real-time characterization to identify the optimal sonication conditions, intensity, and duration for improved stability and uniformity of nanoparticle dispersions without impacting the sample integrity.