title: Separation and characterization of gold nanoparticle mixtures by flow-field-flow fractionation.
abstract: We show that using asymmetric flow-field-flow fractionation and UV-vis detector it is possible to separate, characterize, and quantify the correct number size distribution of gold nanoparticle (AuNP) mixtures of various sizes in the 5-60 nm range for which simple dynamic light scattering measurements give misleading information. The size of the collected nanoparticles fractions can be determined both in solution and in the solid state, and their surface chemistry characterized by NMR. This method will find widespread applications both in the process of "size purification" after the synthesis of AuNP and in the identification and characterization of gold-based nanomaterials in consumer products.
authors.affiliation: European Commission, Joint Research Centre, Institute for Health and Consumer Protection, I-21027 Ispra (VA), Italy. luigi.calzolai@jrc.ec.europa.eu
authors.forename: Luigi
authors.initials: L
authors.lastname: Calzolai
authors.forename: Douglas
authors.initials: D
authors.lastname: Gilliland
authors.forename: César Pascual
authors.initials: CP
authors.lastname: Garcìa
authors.forename: François
authors.initials: F
authors.lastname: Rossi
mesh_terms: D031521:Fractionation, Field Flow / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D019906:Nuclear Magnetic Resonance, Biomolecular; D010316:Particle Size; D012542:Scattering, Radiation
chemical_list: D006046:Gold