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Real-Time Size Discrimination and Elemental Analysis of Gold Nanoparticles using ES-DMA coupled to ICP-MS



Sherrie R. Elzey, De-Hao D. Tsai, Lee L. Yu, Michael R. Winchester, Michael E. Kelley, Vincent A. Hackley


We report the development of a hyphenated instrument with the capacity to quantitatively characterize aqueous suspended gold nanoparticles (AuNPs) based on a combination of gas-phase size separation, particle counting, and elemental analysis. A customized electrospray-differential mobility analyzer (ES-DMA) was used to achieve real-time upstream size discrimination. A condensation particle counter (CPC) and inductively coupled plasma mass spectrometer (ICP-MS) were employed as downstream detectors, providing information on number density and elemental composition, respectively, of aerosolized AuNPs versus the upstream size selected by ES-DMA. A gas-exchange device was designed and optimized to improve the conversion of air flow (from the electrospray) to argon flow required to sustain the ICP-MS plasma, the key compatibility issue for instrumental hyphenation. Our work provides the proof of concept and a working prototype for utilizing this construct to successfully measure (1) number-based and mass-based distributions; (2) elemental compositions of nanoparticles classified by size, where the size classification and elemental analysis are performed within a single experiment; (3) particle concentrations in both solution (before size discrimination) and aerosol (after size discrimination) phases; (4) the number of atoms per nanoparticle or the nanoparticle density.
Analytical and Bioanalytical Chemistry


DMA, electrospray, gold, nanoparticle, ICP-MS, quantitative analysis


Elzey, S. , Tsai, D. , Yu, L. , Winchester, M. , Kelley, M. and Hackley, V. (2013), Real-Time Size Discrimination and Elemental Analysis of Gold Nanoparticles using ES-DMA coupled to ICP-MS, Analytical and Bioanalytical Chemistry, [online],, (Accessed June 21, 2024)


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Created January 21, 2013, Updated October 12, 2021