Comprehensive Analysis of Nanoparticles using Single and Triple Quadrupole ICP-MS and a Dedicated Data Evaluation Tool

Significance of Topic

Nanoparticle characterization has become indispensable in fields such as environmental monitoring, materials science and life sciences. The ability to measure both particle size distribution and number concentration in a single analytical run addresses regulatory requirements on nanomaterials and supports quality control in manufacturing processes.

Aims and Overview of the Study

This study demonstrates a fully integrated workflow for single-particle ICP-MS (spICP-MS) using both single and triple quadrupole instruments. By coupling the Thermo Scientific npQuant software plug-in with Qtegra ISDS, the authors aim to achieve accurate size distributions and particle counts for gold and TiO₂ nanoparticles and to validate results against an independent spreadsheet-based tool.

Methodology and Instrumentation

The analytical approach involved gravimetric dilution of certified 30 nm and 60 nm gold nanoparticles, and commercially supplied TiO₂ particles. Samples were sonicated for dispersion and introduced to the ICP-MS in single-particle mode. Key acquisition parameters were determined automatically by npQuant, minimizing user intervention.

Instrumentation used

• Thermo Scientific iCAP RQ ICP-MS operated in single quadrupole mode with helium collision gas.
• Thermo Scientific iCAP TQ ICP-MS used as a triple quadrupole system with reactive gases (O₂ or NH₃) to overcome isobaric overlaps on ⁴⁸Ti.
• Qtegra ISDS software with the npQuant plug-in for data acquisition and evaluation.

Main Results and Discussion

Size and count data obtained with npQuant matched certified reference values for gold nanoparticles and agreed within error to results from the independent Single Particle Calculation (SPC) tool. Transport efficiency determinations using expected particle size or number agreed within 0.2-0.5% relative standard deviation. TiO₂ measurements on the triple quadrupole instrument achieved low size detection limits (< 31 nm) by applying a mass-shift strategy (⁴⁸Ti→48TiO⁺) and reactive gas filtration to remove Ca and SO⁺ interferences. Sonication studies revealed de-agglomeration and increased detection of sub-50 nm particles.

Benefits and Practical Applications

The npQuant workflow streamlines method setup, parameter optimization and statistical evaluation, making spICP-MS accessible to routine laboratories. Triple quadrupole operation extends applicability to challenging analytes in complex matrices, supporting regulatory compliance and material safety assessments.

Future Trends and Potential Applications

Advances in collision/reaction cell chemistry and data-processing algorithms are expected to further lower detection limits and improve discrimination of mixed nanoparticle populations. Integration with hyphenated separation techniques (FFF, HDC) and multimodal characterization platforms will enable comprehensive profiling of nanomaterials in environmental, food and biomedical samples.

Conclusion

The combined use of single and triple quadrupole ICP-MS with dedicated software provides a robust, automated solution for nanoparticle size and count analysis. Validation against independent tools confirms accuracy, while reactive gas strategies address spectral interferences, broadening the technique’s utility in research and quality control.

References

1. European Commission. Definition of a Nanomaterial. http://ec.europa.eu/environment/chemicals/nanotech/faq/definition_en.htm
2. Thermo Fisher Scientific. Application Note 43330: npQuant Plug-in for Qtegra ISDS.
3. Rikilt – Institute of Food Safety. Single Particle Calculation Tool. https://www.wur.nl/en/show/Single-Particle-Calculation-tool.htm