Asymmetrical-flow field flow fractionation (AFFF) separates constituents based on hydrodynamic size, and is emerging as a powerful tool for obtaining high-resolution information on the size, molecular weight, composition, and stability of nanoscale particles in liquid media. We employ a customized AFFF system combining on-line detectors for multi-angle light scattering (MALS), dynamic light scattering (DLS), and UV-Vis absorption. Our objective is to develop optimized measurement protocols for the characterization of gold nanoparticles (GNPs), which are widely utilized in biomedical research and other nanotechnology applications. Experimental conditions have been optimized by controlling key parameters, including injection volume and solids concentration, mobile phase composition, membrane type and pore size, and ratio of channel-to-cross-flow rates. Individual citrate-stabilized GNP components (10, 20, 30, 40, and GNP60) and GNPs functionalized with polyethylene glycol (PEG) were separated from multi-component GNP mixtures by AFFF and characterized. We discuss the effects due to variations in measurement parameters and GNP surface modification on observed retention, recovery and peak resolution.
Citation: Analytical and Bioanalytical Chemistry
Pub Type: Journals
field flow fractionation, gold nanoparticle, fractionation, size characterization, light scattering, polyethyleneglycol