Evaluation of miniaturized ultrasonic nebulization for high-efficiency sampling in characterization of silver nanoparticles by single particle inductively coupled plasma mass spectrometry†

Single particle inductively coupled plasma mass spectrometry (spICP-MS) has become a powerful tool for the simultaneous characterization of the size, elemental composition and concentration of nanoparticles (NPs). However, the conventional pneumatic nebulization (PN) sampling system used in spICP-MS suffers from low transport efficiency (1–5%), limiting its effectiveness in analyzing environmentally relevant samples with low NP concentrations. To address this limitation, we evaluated a self-designed high-efficiency miniaturized ultrasonic nebulization (MUN) sampling system for spICP-MS analysis. This novel sampling system achieves an exceptionally high transport efficiency of approximately 80% for silver (Ag) NPs. Remarkably, this high transport efficiency is maintained across a sample uptake rate range of 10–25 μL min⁻¹, outperforming other reported highly efficient nebulizers where TE significantly decreased with the increase in sampling rate. The effectiveness and reliability of the MUN system were further demonstrated by analyzing standard Ag NPs of 60 nm and 100 nm, confirming the accurate characterization of particle size distribution. Overall, our MUN-spICP-MS offers a cost-effective and highly efficient method for characterizing NPs, which is of great significance for the NP characterization in natural environmental samples with low particle sizes and concentrations.