Improved validation for single particle ICP-MS analysis using a pneumatic nebulizer / microdroplet generator sample...

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Accurate characterization of nanoparticles (NPs) is crucial for understanding their behavior and applications.
• Existing single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) methods require robust validation for reliable NP quantification.
• Multi-mode analysis offers enhanced validation capabilities for complex nanoparticle samples.

Purpose of the Study:

• To develop and validate a novel multi-mode sp-ICP-MS technique for simultaneous determination of NP metal mass fraction and number concentration.
• To establish a robust analytical method capable of performing three independent analyses within a single run.
• To improve the validation capabilities of sp-ICP-MS for nanoparticle characterization.

Main Methods:

• Development of a dual inlet system (pneumatic nebulizer and microdroplet generator) for sequential introduction of calibrants and NP suspensions.
• Assembly of a novel interface using standard analytical components for seamless integration with ICP-MS.
• Implementation of three distinct analysis modes, each based on a different calibration principle, for comprehensive NP characterization.

Main Results:

• The developed sp-ICP-MS technique successfully determined NP metal mass fraction and number concentration across three independent modes.
• Analysis of gold (Au), silver (Ag), and cerium dioxide (CeO2) nanoparticles showed good agreement in size determination across all modes.
• High recoveries (91-100%) for Au and Ag NP number concentrations were achieved with modes I and II, while mode III yielded 70-88% recovery.

Conclusions:

• The novel multi-mode sp-ICP-MS technique provides a robust and efficient platform for nanoparticle characterization.
• The ability to perform three independent analyses within a single run significantly enhances the validation of sp-ICP-MS results.
• The method demonstrates excellent performance for Au and Ag NPs, with potential limitations for highly polydisperse or agglomerated NPs like CeO2.