Size of monodispersed nanomaterials evaluated by dynamic light scattering: Protocol validated for measurements of 60 and 203nm diameter nanomaterials is now extended to 100 and 400nm

[Display omitted] In vivo fate of nanomaterials is influenced by the particle size among other parameters. Thus, Health Agencies have identified the size of nanomaterial as an essential physicochemical property to characterize. This parameter can be explored by dynamic light scattering (DLS) that is described in the ISO standard 22412:2008(E) and is one of the methods recognized by Health Agencies. However, no protocol of DLS size measurement has been validated over a large range of size so far. In this work, we propose an extension of validation of a protocol of size measurement by DLS previously validated with certified reference materials (CRM) at 60 and 203nm. The present work reports robustness, precision and trueness of this protocol that were investigated using CRM at 100 and 400nm. The protocol was robust, accurate and consistent with the ISO standard over the whole range of size that were considered. Expanded uncertainties were 4.4 and 3.6% for CRM at 100 and 400nm respectively indicating the reliability of the protocol. The range of application of the protocol previously applied to the size measurement of liposomes and polymer nanoparticles was extended to inorganic nanomaterial including silica nanoparticles.