Agilent ICP-MS Journal (October 2020, Issue 82)

Significance of the topic

High-performance trace analysis by inductively coupled plasma mass spectrometry (ICP-MS) and its triple quadrupole variant (ICP-MS/MS or ICP-QQQ) underpins critical applications in semiconductor manufacturing, food safety, and environmental monitoring. Contaminant control at sub-parts-per-billion levels ensures device reliability in III-V compound semiconductors and protects infant health against toxic elements such as inorganic arsenic. Recent advances in coupling gas and liquid chromatography to ICP-MS have expanded the analytical scope, enabling rapid speciation, interference-free quantitation, and improved data quality.

Objectives and overview

This collection of studies and event reports illustrates:

• A GC-ICP-QQQ method for ultratrace measurement of hydride gas contaminants (SiH4, PH3, H₂S, GeH4) in arsine used for III-V semiconductor production.
• An HPLC-ICP-MS workflow supporting compliance with the new FDA action level (100 µg/kg) for inorganic arsenic in infant rice cereals, delivering rapid speciation of As(III)/As(V).
• A series of webinars showcasing ICP-QQQ solutions for semiconductor process chemicals, nanoparticle analysis, and challenging matrix elements like chlorine.
• The application of MS/MS with oxygen reaction gas for accurate low-level sulfur determination and isotope ratio measurement.

Used Instrumentation

Key platforms include:

• Agilent 7890B GC interfaced to Agilent 8900 ICP-QQQ via a high-flow Deans switch.
• Agilent 1260 HPLC coupled to Agilent 7900 single-quadrupole ICP-MS and to 8900 ICP-QQQ.
• High-performance software control with MassHunter, enabling multi-tune methods and automated internal standard monitoring.

Main results and discussion

GC-ICP-QQQ achieved sub-ppb detection limits in a single 24 ppb arsine standard run by dynamically switching cell gases (H₂, O₂) and tune settings. Detection limits were 0.01 ppb for GeH₄, 0.02 ppb for PH₃, 0.15 ppb for H₂S and 0.51 ppb for SiH₄. HPLC-ICP-MS speciation of As(III)/As(V) in infant cereals met FDA guidelines, with full separation in under two minutes via in-sample oxidation and isocratic anion exchange. Market-basket testing revealed some samples exceeding the 100 ppb inorganic As limit. The webinars highlighted detection of 15 nm Fe₃O₄ nanoparticles at ppq levels by single-particle ICP-MS, and optimized MS/MS methods for Cl analysis in organic matrices. Sulfur analysis using oxygen cell gas in ICP-QQQ removed interferences and improved isotope ratio accuracy.

Benefits and practical applications

These integrated chromatographic–ICP-MS workflows provide robust, interference-free quantitation of critical analytes in complex matrices. Semiconductor producers gain real-time control of gas and liquid precursor purity, while food manufacturers adopt rapid speciation to ensure regulatory compliance and consumer safety. Automated tune switching and advanced software tools enhance throughput and data confidence.

Future trends and possibilities

Expanding triple-quadrupole ICP-MS to additional elements (e.g., fluorine, sulfur isotopes) and novel matrices (nanoparticles, organometallics) will continue. Automation of standard addition, remote sampling systems, and AI-driven QC are poised to streamline routine analysis. Further improvements in cell gas chemistries and mass filter resolution will lower detection limits and broaden speciation capabilities.

Conclusion

The convergence of advanced chromatography interfaces, ICP-QQQ/MS/MS, and intelligent software delivers unparalleled sensitivity, selectivity, and speed for trace and speciation analysis. These methods address critical industry needs in semiconductors and food safety, with clear pathways for future innovation.

References

1. Geiger WM, McElmurry B, Anguiano J, Kelinske M. Agilent publication 5994-2213EN.
2. US FDA. Guidance for Industry: Action Level for Inorganic Arsenic in Rice Cereals for Infants, 2020.
3. US FDA EAM Section 4.11. Arsenic Speciation in Rice Products Using HPLC-ICP-MS.
4. Juskelis R, Li W, Nelson J, Cappozzo JC. J Agric Food Chem. 2013;61(45):10670–10676.
5. Gray PJ, Tanabe CK, Ebeler SE, Nelson J. J Anal At Spectrom. 2017;32:1031–1034.
6. Tanabe CK, Ebeler SE, Nelson J. Agilent publication 5991-9488EN.
7. McCurdy E, Woods G, Georg B, Sugiyama N. SpectroscopyOnline, Accurate Low-Level Sulfur Analysis by ICP-MS/MS.