title: Quantitative characterization of gold nanoparticles by field-flow fractionation coupled online with light scattering detection and inductively coupled plasma mass spectrometry.
abstract: An analytical platform coupling asymmetric flow field-flow fractionation (AF(4)) with multiangle light scattering (MALS), dynamic light scattering (DLS), and inductively coupled plasma mass spectrometry (ICPMS) was established and used for separation and quantitative determination of size and mass concentration of nanoparticles (NPs) in aqueous suspension. Mixtures of three polystyrene (PS) NPs between 20 and 100 nm in diameter and mixtures of three gold (Au) NPs between 10 and 60 nm in diameter were separated by AF(4). The geometric diameters of the separated PS NPs and the hydrodynamic diameters of the Au and PS NPs were determined online by MALS and DLS, respectively. The three separated Au NPs were quantified by ICPMS and recovered at 50-95% of the injected masses, which ranged between approximately 8-80 ng of each nanoparticle size. Au NPs adhering to the membrane in the separation channel was found to be a major cause for incomplete recoveries. The lower limit of detection (LOD) ranged between 0.02 ng Au and 0.4 ng Au, with increasing LOD by increasing nanoparticle diameter. The analytical platform was applied to characterization of Au NPs in livers of rats, which were dosed with 10 nm, 60 nm, or a mixture of 10 and 60 nm nanoparticles by intravenous injection. The homogenized livers were solubilized in tetramethylammonium hydroxide (TMAH), and the recovery of Au NPs from the livers amounted to 86-123% of their total Au content. In spite of successful stabilization with bovine serum albumin even in alkaline medium, separation of the Au NPs by AF(4) was not possible due to association with undissolved remains of the alkali-treated liver tissues as demonstrated by electron microscopy images.
authors.affiliation: Department of Basic Sciences and Environment, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Schmidt
authors.forename: Katrin
authors.initials: K
authors.lastname: Loeschner
authors.forename: Niels
authors.initials: N
authors.lastname: Hadrup
authors.forename: Alicja
authors.initials: A
authors.lastname: Mortensen
authors.forename: Jens J
authors.initials: JJ
authors.lastname: Sloth
authors.forename: Christian Bender
authors.initials: CB
authors.lastname: Koch
authors.forename: Erik H
authors.initials: EH
authors.lastname: Larsen
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D031521:Fractionation, Field Flow / Q000379:methods*; D006046:Gold / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D008027:Light; D008099:Liver / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D053768:Metal Nanoparticles / Q000032:analysis* / Q000737:chemistry; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D013535:Suspensions
chemical_list: D013535:Suspensions; D006046:Gold