Agilent ICP-MS Journal (July 2020, Issue 81)

Significance of the Topic

The Agilent ICP-MS Journal issue highlights emerging applications of inductively coupled plasma mass spectrometry (ICP-MS) and ICP-QQQ in materials science, environmental monitoring, and instrumentation development. The integration of laser ablation and laser-induced breakdown spectroscopy extends direct solid analysis capabilities. Monitoring trace rare earth elements (REEs) in natural waters addresses growing environmental concerns due to industrial and medical uses. Understanding plasma robustness underpins reliable, high-performance ICP-MS analysis across challenging matrices.

Objectives and Overview of the Publication

This publication presents three key advances: tandem laser ablation–ICP-MS combined with LIBS for direct solids analysis; a mass-shift MS/MS method for ultratrace REE determination in river water; and an exploration of plasma robustness effects on ICP-MS performance. Each article demonstrates improved sensitivity, interference control, and practical workflows for routine and research laboratories.

Methodology and Instrumentation

• Tandem LA-LIBS-ICP-QQQ: Applied Spectra J200 laser ablation system coupled to an Agilent 8900 ICP-QQQ. Pulsed lasers ablate sample surfaces to generate aerosols and LIBS plasmas, enabling simultaneous optical emission and mass spectra collection.
• REE Analysis in Water: Direct analysis of filtered, acidified Tama River samples using Agilent 8900 ICP-QQQ in MS/MS mass-shift mode with N2O reaction gas for O-atom transfer. Method detection limits for all REEs were below 0.13 ppt.
• Plasma Robustness Study: Evaluation of CeO/Ce ratio, torch injector diameter, carrier gas velocity, and high matrix introduction (HMI) on molecular suppression and ionization efficiency. Agilent ICP-MS systems maintained CeO/Ce ~1 % and effectively handled samples up to percent-level dissolved solids.

Main Findings and Discussion

• LA-LIBS-ICP-QQQ applications demonstrated extended elemental coverage including non-metals (C, H, O, N, F, Cl) and resolved challenging interferences (e.g., Ni alloy P analysis, Sc in Zr matrix). A 3D LIBS map of a pallasite meteorite illustrated high spatial resolution.
• REE measurements along the Tama River showed smooth normalized profiles except for a gadolinium spike downstream of wastewater treatment plant outlets, indicating anthropogenic contamination likely from MRI contrast agents.
• Plasma robustness optimization revealed that lower CeO/Ce and wider torch injectors increase effective plasma temperature and ionization, enhancing sensitivity for elements such as As, Cd, Hg, and Pb. HMI further extended matrix tolerance with consistent recoveries in high-salinity samples.

Benefits and Practical Applications

• Direct solids analysis reduces sample preparation time and contamination risk.
• Enhanced sensitivity and interference removal support trace-level environmental and geological analyses.
• Expanded elemental coverage via combined LIBS and ICP-MS enables comprehensive characterization of complex materials.
• Robust plasma conditions and HMI ensure reliable performance for high-matrix samples in industrial, environmental, and life-science laboratories.

Future Trends and Opportunities

• Integration of advanced laser sampling with ICP-MS and AI-driven data analysis for real-time, in situ measurements.
• Expanded use of triple quadrupole MS/MS techniques to address emerging analytes and complex matrices.
• Development of standardized workflows for REE monitoring to support environmental regulations.
• Continued innovation in plasma source design, high-throughput automation, and multimodal elemental mapping.

Conclusion

The articles demonstrate how coupling laser ablation and LIBS with ICP-QQQ, along with optimized plasma conditions, significantly advances elemental analysis capabilities. These innovations enable unprecedented sensitivity, interference control, and matrix tolerance, meeting the evolving needs of analytical chemistry in environmental, industrial, and research applications.

References

1. Sugiyama N., Agilent publication 5994-1785EN.
2. Nance W.B., Taylor S.R., Rare earth element patterns and crustal evolution—I. Australian post-Archean sedimentary rocks, Geochimica et Cosmochimica Acta, Vol. 40, Issue 12, 1976, 1539–1551.