Search

To realize a ∼100% transport efficiency (TE) and a high-throughput sample analysis for nanoparticle characterization using single-particle inductively coupled plasma mass spectrometry (spICP-MS), three sample introduction systems, including a high-performance concentric nebulizer with a heated cyclonic spray chamber and a three-stage Peltier-cooled desolvation system (HPCN-APEX), a conventional sample introduction system (i.e., the commercially available MicroMist nebulizer with a cyclonic spray chamber), and a total consumption (TC) system, were evaluated and compared. The TEs of the HPCN-APEX and TC systems were almost 100% at sample uptake rates of 103 and 9.8 μL min−1, respectively, whereas that of the conventional sample introduction system was only 10% at an uptake rate of 112 μL min−1. Because of the dried aerosol conditions in HPCN-APEX, the size and number detection limits of HPCN-APEX were 1.6-fold and 10-fold lower than those of the TC system. The HPCN-APEX showed better detection efficiency for smaller particles and lower particle numbers. This is beneficial not only for environmental monitoring but also for the ultra-trace analysis of particle impurities in semiconductor process chemicals. [ABSTRACT FROM AUTHOR]

In order to facilitate reliable and efficient determination of both the particle number concentration (PNC) and the size of nanoparticles (NPs) by single-particle ICP-MS (spICP-MS) without the need to correct for the particle transport efficiency (TE, a possible source of bias in the results), a total-consumption sample introduction system consisting of a large-bore, high-performance concentric nebulizer and a small-volume on-axis cylinder chamber was utilized. Such a system potentially permits a particle TE of 100 %, meaning that there is no need to include a particle TE correction when calculating the PNC and the NP size. When the particle TE through the sample introduction system was evaluated by comparing the frequency of sharp transient signals from the NPs in a measured NP standard of precisely known PNC to the particle frequency for a measured NP suspension, the TE for platinum NPs with a nominal diameter of 70 nm was found to be very high (i.e., 93 %), and showed satisfactory repeatability (relative standard deviation of 1.0 % for four consecutive measurements). These results indicated that employing this total consumption system allows the particle TE correction to be ignored when calculating the PNC. When the particle size was determined using a solution-standard-based calibration approach without an NP standard, the particle diameters of platinum and silver NPs with nominal diameters of 30-100 nm were found to agree well with the particle diameters determined by transmission electron microscopy, regardless of whether a correction was performed for the particle TE. Thus, applying the proposed system enables NP size to be accurately evaluated using a solution-standard-based calibration approach without the need to correct for the particle TE. [ABSTRACT FROM AUTHOR]