Element XR HR-ICP-MS with Jet Interface in dry plasma: exceptional detection sensitivity and improved abundance sensitivity

Significance of the Topic

The analysis of trace elements with high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) is critical in environmental monitoring, nuclear forensics, and quality control. Enhancing detection sensitivity and abundance sensitivity improves the ability to quantify ultra-trace analytes and resolve spectral interferences.

Study Objectives and Overview

This study evaluates the performance gains achieved by coupling a Thermo Scientific Element XR HR-ICP-MS equipped with the Jet Interface to desolvating nebulizer systems under dry plasma conditions. It compares detection and abundance sensitivity against conventional wet plasma measurements.

Methodology

Experiments included a baseline wet plasma measurement (WP1) and four dry plasma configurations (DP1–DP4) using ESI Apex 2Q and Apex Omega desolvating systems. Operating parameters such as RF power, gas flows, and sample introduction rates were optimized to maximize sensitivity and minimize oxide formation. Abundance sensitivity tests (DP5) measured uranium isotopes at varying filter lens voltages.

Used Instrumentation

• Thermo Scientific Element XR HR-ICP-MS with Jet Interface (Jet sample cone, X skimmer cone, high-capacity pump)
• ESI Apex 2Q and Apex Omega desolvating nebulizer systems with PFA APEX nebulizers and quartz spray chambers
• Standard Twinnabar quartz cyclonic spray chamber and MicroMist nebulizer for wet plasma measurements
• Detection system: Secondary Electron Multiplier (SEM) and Faraday cup with electrostatic filter lens (ESA)

Main Results and Discussion

• Dry plasma sensitivity increased by 30–50× compared to wet plasma without the Jet Interface, reaching ~3–5×10^7 cps/ppb for 115In.
• The Apex Omega system achieved the highest sensitivity (~5–7×10^7 cps/ppb) under optimized gas flows and tuning.
• Abundance sensitivity around the 238U peak improved to <7 ppm in dry plasma, further enhanced to 5–7 ppm using a filter lens at 11–13 V.
• Applying the filter lens reduced signal intensity (to 44% at 11 V and 21% at 13 V) but significantly suppressed peak tails.
• Dry plasma conditions effectively suppressed uranium hydride formation, providing symmetrical abundance sensitivity and enabling ultra-trace Pu isotope analysis.
• The system’s dynamic range (>10^12 cps) accommodated high-intensity signals arising from enhanced sensitivity.

Benefits and Practical Applications

• Lower detection limits and improved spectral resolution for trace element quantification.
• Enhanced precision in isotopic ratio measurements for environmental, geochemical, and nuclear investigations.
• Robust long-term signal stability supports routine QA/QC and multi-element workflows.
• Applications span environmental monitoring, nuclear safeguards, pharmaceutical QA, and process control.

Future Trends and Possible Applications

• Further refinement of desolvation and interface parameters for diverse sample matrices.
• Integration with advanced sample introduction techniques such as laser ablation and aerosol generation.
• Extension to ultra-trace analysis of transuranic isotopes, nanoparticles, and biomolecules.
• Real-time monitoring systems for industrial process analytics and environmental surveillance.
• Development of isotopic fingerprinting tools for provenance and forensic applications.

Conclusion

Coupling the Element XR HR-ICP-MS with the Jet Interface under dry plasma conditions dramatically enhances detection and abundance sensitivity, suppresses hydride interferences, and expands the dynamic range. Optimized tuning and desolvation strategies enable ultra-trace measurements and reliable isotope ratio analysis across diverse applications.

References

1. Roberts J et al. Thermo Scientific Application Note 30685: The Jet Interface: improving sensitivity of trace element analysis.
2. Bracciali L et al. Thermo Scientific Application Note 30824: Long term multi-element signal stability in wet plasma by Element Series HR ICP-MS.
3. Hamester M et al. Thermo Scientific Application Note 30104: Enhancing the Performance of Single Collector Sector Field ICP-MS for Isotope Ratio Determinations.
4. Thermo Scientific. Product Specification PS30436-EN 0820S.
5. Zheng J. Evaluation of a new sector-field ICP-MS with Jet Interface for ultra-trace determination of Pu isotopes: from femtogram to attogram levels. J. Nucl. Radiochem. Sci. 2015;15:7–13.
6. Igarashi H et al. First determination of Pu isotopes in radioactive particles derived from Fukushima Daiichi Nuclear Power Plant accident. Sci. Rep. 2019;9:11807.