Size Analysis of Small Metal Nanoparticles Using Single Particle ICP Mass Spectrometry.

For size analysis of small nanoparticles (i.e., nanoparticles smaller than 10 nm) using spICP-MS, two approaches were employed to improve the signal-to-noise ratio of ion signals emanating from small nanoparticles. The first one was enhancement of the instrumental sensitivity using a desolvating system. The second approach was separation of the ion signals from background signals through a deconvolution method. A combination of these approaches enabled us to measure 5 nm gold nanoparticles, and the calculated size detection limit was 3.8 nm.