CE Coupled to ICP-MS and Single Particle ICP-MS for Nanoparticle Analysis.

Capillary electrophoresis (CE) can be used for the separation of nanoparticles (NPs). Coupling of CE to inductively coupled plasma mass spectrometry (ICP-MS) or single particle (sp)-ICP-MS enhances the analytical performance and capabilities of the method compared to CE with a standard detector (ultraviolet visible spectroscopy), in particular for trace analysis of metals or metal-containing compounds. spICP-MS is a method for NP analysis, where a standard ICP-MS setup is used with fast time-resolved detection in order to obtain information on individual NPs. Here we describe a method for the separation and detection of silver and gold NPs using CE-ICP-MS and CE-spICP-MS with reversed electrode polarity stacking mode (REPSM) for online preconcentration. CE-spICP-MS allows obtaining the average size, size distribution, elemental composition, and particle number concentration (PNC) of NPs in addition to a CE separation profile in a single run. Moreover, CE-spICP-MS can be used in some cases to separate NPs with different coatings.