Separation and detection of gold nanoparticles with capillary electrophoresis and ICP-MS in single particle mode (CE-SP-ICP-MS)

In this work, we describe a method for the identification, separation, and detection of engineered nanoparticles (NPs) using capillary electrophoresis inductively coupled plasma-mass spectrometry in single particle mode (CE-SP-ICP-MS). Benefits of this method compared to conventional techniques include the fact that complex NPs mixtures are characterized on a particle-by-particle basis, separated with acceptable resolution, and in much shorter time. Information on particle number, particle mean size, size distribution, and elemental composition is obtained and visualized in three-dimensional single-particle electropherograms for the first time. The successful detection and characterization of single 10 nm-sized AuNPs with ICP-MS is demonstrated. Based on these results we believe that this method will become an important tool in high-throughput analysis, fractionation analysis, and in situ particle characterization.