Identification and Accurate Size Characterization of Nanoparticles in Complex Media

We have developed a new method for the identification and accurate size characterization of nanoparticles (NPs) in complex media based on capillary electrokinetic (CE) separation coupled to inductively coupled plasma mass spectrometry (ICP‐MS). Through mass scanning and Gaussian fitting of electropherogram peaks, we can obtain multidimensional information on chemical compositions, size distributions, and ionic species of multiple NPs in a single run. The results are more accurate than those obtained by using conventional methods. This method provides a powerful tool for investigating polydisperse NP systems and rapid screening of NP‐containing products. (Nano)size matters: Capillary electrokinetic separation and inductively coupled plasma mass spectrometry (ICP‐MS) were combined in a method that allows the identification and accurate size determination of nanoparticles in complex media (see picture). This method provides a powerful tool for investigating polydisperse multiple NP systems and rapid screening of NP‐containing products.