Analysis of 10 nm Gold Nanoparticles using the Agilent 7800 ICP-MS

Significance of the Topic

Monitoring nanoparticles like 10 nm gold is critical for various applications such as catalysis, biomedicine, and environmental analysis. Detecting smaller particles challenges instruments due to the cube-root dependence of signal upon diameter, requiring enhanced sensitivity.

Study Objectives and Overview

This work demonstrates that the Agilent 7800 ICP-MS can reliably detect and size 10 nm Au nanoparticles under standard operating conditions without reactive cell gases or custom tuning. The method is extended to mixtures of different size particles and is adaptable to other metallic nanoparticles.

Methodology and Instrumentation

Analyses were performed on the Agilent 7800 ICP-MS equipped with a MicroMist concentric nebulizer, double-pass quartz spray chamber, and optional 1.5 mm quartz torch. Fast time-resolved acquisition (100 μs integration) enabled clear peak definition. No-gas mode in the ORS cell was used, tuning for Au at m/z 197 with ~2% oxide. MassHunter Single Nanoparticle Application Module automated method creation, data acquisition, and calculation of nebulization efficiency using NIST 8012.

Main Results and Discussion

Signal for 10 nm Au (NIST 8011) was accurately detected with a background equivalent diameter of ~5 nm. Size distributions matched certified mean and mode values of 10 nm. In mixed samples containing 10 nm and 30 nm particles, the two populations were clearly resolved in size distribution plots. Automated thresholding algorithms effectively separated particle events from baseline noise.

Benefits and Practical Applications

Analyses are rapid (≈60 seconds per sample) and the full sequence including calibration and efficiency determination can be completed in under 30 minutes. The high sensitivity and simple no-gas conditions facilitate routine measurement of small nanoparticles. The approach is readily transferable to other elements, such as silver, using the same setup.

Future Trends and Possibilities

• Expanding to complex or mixed-composition nanoparticles and multimodal size distributions
• Incorporating advanced data analytics and machine learning for improved sample classification
• Enhancing throughput with multiplexed introduction and real-time monitoring

Conclusion

The Agilent 7800 ICP-MS coupled with MassHunter Single Nanoparticle Application Module provides a robust, sensitive, and user-friendly workflow for characterizing 10 nm gold nanoparticles and mixtures, with broad applicability across research and quality control environments.

Reference

Agilent Technologies, Application Overview 5991-8827EN, December 2017