Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles
Caterina Minelli, Magdalena Wywijas, Dorota Bartczak, Susana Cuello-Núñez, Heidi Goenaga‐Infante, Jérôme Deumer, Christian Gollwitzer, Michael Krumrey, Karen E. Murphy, Monique E. Johnson, Antonio R. Montoro Bustos, Ingo Strenge, Bertrand Faure, Peter Høghøj, Vivian Tong, Loïc Burr, Karin Norling, Fredrik Höök, Matthias Roesslein, Jovana Kocic, Lyndsey Hendriks, Vikram Kestens, Yannic Ramaye, Maria C. Contreras Lopez, Guy Auclair, Dóra Méhn, Gilliland Douglas, Annegret Potthoff, Kathrin Oelschlägel, Jutta Tentschert, Harald Jungnickel, Benjamin Krause, Yves U. Hachenberger, Philipp Reichardt, Andreas Luch, Thomas E. Whittaker, Molly M. Stevens, Shalini Gupta, Akash Singh, Fang-hsin Lin, Yi‐Hung Liu, Anna Luisa Costa, Carlo Baldisserri, Rid Jawad, Samir EL Andaloussi, Margaret N. Holme, Tae Geol Lee, Minjeong Kwak, Jaeseok Kim, Johanna Ziebel, Cédric Guignard, Sébastien Cambier, Servane Contal, Arno C. Gutleb, Jan “Kuba” Tatarkiewicz, Bartłomiej Jankiewicz, Bartosz Bartosewicz, Xiaochun Wu, Jeffrey Fagan, Elisabeth Elje, Elise Rundén‐Pran, Mária Dušinská, Inder Preet Kaur, David L. Price, Ian Nesbitt, Sarah O′ Reilly, Ruud Peters, Guillaume Bucher, Dennis D. Coleman, Angela J. Harrison, Antoine Ghanem, Anne Gering, Eileen McCarron, Niamh Fitzgerald, Geert Cornelis, Jani Tuoriniemi, Midori Sakai, Hidehisa Tsuchida, Ciarán Manus Maguire, Adriele Prina‐Mello, Alan J. Lawlor, Jessica Adams, Carolin Schultz, Doru Constantin, Nguyễn Thị Kim Thanh, Le Duc Tung, Luca Panariello, Spyridon Damilos, Asterios Gavriilidis, Iseult Lynch, Benjamin Fryer, Ana C. Quevedo, Emily J. Guggenheim, Sophie M. Briffa, Eugenia Valsami‐Jones, Yuxiong Huang, Arturo A. Keller, Virva Kinnunen, Siiri Perämäki, Željka Krpetić
Abstract
We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles.