Quantitative characterization of gold nanoparticles by size-exclusion and hydrodynamic chromatography, coupled to inductively coupled plasma mass spectrometry and quasi-elastic light scattering
Leena M. Pitkanen, Antonio Montoro Bustos, Karen E. Murphy, Michael R. Winchester, Andre Striegel
The physicochemical characterization of nanoparticles, in general, and of gold nanoparticles (Au NPs), in particular, is of paramount importance for tailoring and optimizing the properties of these materials in specific applications, as well as for evaluating the environmental fate and impact of the NPs. Characterizing the properties, most notably size and chemical identity, of disperse sample populations, or of multicomponent blends, is best done by coupling size- based separation methods to physical and chemical detection methods. Informed decisions regarding the NPs can only be made, however, if the separations themselves are quantitative. We undertake here the size-exclusion chromatographic characterization of Au NPs spanning a six- fold range in mean size. The main problem which has plagued the SEC analysis of Au NPs, namely lack of quantitation accountability due to generally poor NP recovery from the columns, is overcome by, first, carefully matching eluent formulation with the appropriate stationary phase chemistry and, second, by the use of on-line inductively coupled plasma mass spectrometry (ICP- MS) detection. Here, for the first time, we demonstrate the quantitative analysis of Au NPs by SEC/ICP-MS, including the analysis of ternary NP blends. The SEC separations are contrasted to HDC/ICP-MS separations employing the same stationary phase chemistry. In both cases, the use of on-line ICP-MS detection has enabled quantitation of column recoveries, which were found to match, if not exceed, the best results reported to date using alternative methods. Additionally, analysis of Au NPs by HDC with on-line quasi-elastic light scattering (QELS) allowed for continuous determination of NP size across the chromatographic profiles, overcoming issues of column fines shedding experienced during the SEC analyses. The use of homogeneous, well-characterized reference materials allowed for increased accuracy and precision and for a more direct interpretation of results than
, Montoro Bustos, A.
, Murphy, K.
, Winchester, M.
and Striegel, A.
Quantitative characterization of gold nanoparticles by size-exclusion and hydrodynamic chromatography, coupled to inductively coupled plasma mass spectrometry and quasi-elastic light scattering, Journal of Chromatography A, [online], https://doi.org/10.1016/j.chroma.2017.06.064, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921190
(Accessed June 7, 2023)