Separating and measuring the physical and chemical properties of monometallic and bimetallic engineered nanoparticles (NPs) is challenging, especially when mixtures of NPs consist of particles of similar size, composition, and especially when present at low concentrations. Fully characterizing suspensions of NPs usually requires a multimethod approach to yield the most reliable results. However, this process becomes increasingly difficult for more complex bimetallic NPs used in some applications or for those that require a mixture of different NPs, since differentiating between NPs can be a slow and arduous task.
As a standalone technique, single particle ICP-MS (SP-ICP MS) has emerged as the technique of choice for the detection of metallic NPs at environmental levels, providing particle size, size distribution, and particle number concentration all on particle per particle basis. This work demonstrates the ability of the NexION® SP-ICP-MS to accurately size, measure and count NPs in complex mixtures of monometallic and bimetallic NPs.