Characterization and Determination of Silver Nanoparticle Using Single Particle-Inductively Coupled Plasma-Mass Spectrometry
Abstract A single particle-inductively coupled plasma mass spectrometry (SP-ICP-MS) method was established to detect the size distribution and number concentrations of silver nanoparticles (AgNPs) in dilute aqueous solution. The optimal dwell time was 3 ms to reduce possibility of two or more particles entering simultaneously into detector. An iterative algorithm was applied to distinguish AgNPs as outliers from baseline and dissolved metal ion signal if measured intensity was beyond five time standard deviation of whole data. The size distribution and number concentration of three commercial silver nanoparticle dispersions (nominal diameters of 30, 50 and 100 nm) were determined by SP-ICP-MS. The result of SP-ICP-MS was accurately similar to that of TEM, indicating that SP-ICPMS could be used to detect silver nanoparticles. The particle size detection limit was 25 nm and the limit of number concentration was 8 × 104 particles L−1 in dilute solution. Tap water being added with silver nanoparticles was tested to obtain a similar size distribution and number concentration. This method was simple, fast and highly sensitive, and quite feasible to investigate the risk assessment of silver nanoparticles in aqueous environment and monitor silver nanoparticles in drinking water.