Agilent ICP-MS Journal (February 2015 – Issue 60)

Importance of the Topic

Inductively coupled plasma mass spectrometry (ICP-MS) and its advanced variants have become indispensable tools for ultra-trace elemental analysis across diverse fields. Precise control of metal impurities is critical in semiconductor fabrication, while nanoparticle characterization informs consumer safety and environmental monitoring. The ability to detect lead additives in aviation fuels safeguards engine performance and public safety. Continuous innovation in ICP-MS instrumentation further expands analytical capabilities and application domains.

Objectives and Overview of the Articles

This issue presents four distinct studies illustrating ICP-MS versatility:

• An evaluation of the Agilent 8800 triple quadrupole ICP-MS (ICP-QQQ) for quantifying metal contaminants on silicon wafers in semiconductor processing.
• Development of a capillary electrophoresis–ICP-MS (CE-ICP-MS) method for multi-element nanoparticle identification, sizing and quantification in consumer products and water.
• Application of gas chromatography–ICP-MS (GC-ICP-MS) to profile hydrocarbons and tetraethyllead in aviation gasoline (AvGas) samples.
• A historical perspective on three decades of ICP-MS innovation culminating in the Agilent 7900 and 8800 systems.

Methodology and Instrumentation

• ICP-QQQ (Agilent 8800) equipped with PFA nebulizer, sapphire injector, H₂/O₂ cell gases and MS/MS mode for interference removal in vapor phase decomposition (VPD) wafer scans.
• CE-ICP-MS using an Agilent 7500ce with fused-silica capillary and tris-borate buffer, enabling separation and mass-specific detection of metal NPs and ionic species.
• GC-ICP-MS coupling an Agilent 7890 GC to a 7900 ICP-MS in time-resolved analysis for simultaneous ¹³C and ²⁰⁴Pb/²⁰⁸Pb monitoring of AvGas fractions.
• Instrumentation evolution from early PMS series bench-top ICP-MS to benchtop 4500, 7500 Series with Octopole Reaction System, 7700 miniaturized design, and triple quadrupole 8800.

Main Results and Discussion

• In semiconductor wafers, the 8800 ICP-QQQ achieved detection limits below 1 ppt for most elements and successfully eliminated Si-based polyatomic interferences (e.g., SiOF⁺ on Cu) by MS/MS and optimized cell gases.
• CE-ICP-MS resolved citrate-coated Ag and Au nanoparticles in a single run, yielding size distributions consistent with TEM and DLS, detecting ionic vs. particulate forms, and achieving >88% recoveries in environmental waters.
• GC-ICP-MS analysis of suspect AvGas samples revealed identical hydrocarbon profiles and TEL concentrations (~0.43 g/L) to control fuel, with no heavy naphtha contamination detected.
• Historical review showed successive instrument generations improving sensitivity, matrix tolerance, dynamic range and user-friendly operation, driven by innovations such as ORS cell, helium collision mode, and triple quadrupole filtering.

Benefits and Practical Applications of the Methods

• ICP-QQQ enables reliable wafer surface monitoring for quality control in semiconductor fabs.
• CE-ICP-MS offers multi-element NP sizing and speciation for consumer safety, environmental surveillance and nanomaterials research.
• GC-ICP-MS delivers fast, concurrent hydrocarbon and metal additive profiling for fuel authentication and regulatory compliance.
• Agilent’s evolving platforms provide laboratories with scalable solutions for trace, ultra-trace and interference-free elemental analysis.

Future Trends and Opportunities

• Expansion of multi-quadrupole ICP-MS for targeted reaction chemistry and improved interference control.
• Integration of hyphenated techniques (CE, GC, LC) with ICP-QQQ for comprehensive speciation workflows.
• Advances in micro- and nano-sampling interfaces to accommodate emerging sample types and matrices.
• Application of machine learning for automated data processing, anomaly detection and method optimization.

Conclusion

The studies showcase ICP-MS and its advanced configurations as highly versatile platforms for ultra-trace and speciation analysis in semiconductor, environmental, consumer product and fuel testing. Continuous technological innovation ensures that ICP-MS remains at the forefront of analytical chemistry, addressing ever-more complex interference challenges and expanding into new application areas.

Reference

• K. Mizobuchi and M. Yukinari, Agilent 8800 ICP-QQQ in cool plasma reaction cell mode for ultrapure water analysis, Agilent publication 5991-5372EN (2014).
• L. Liu et al., Identification and Accurate Size Characterization of Nanoparticles in Complex Media by CE-ICP-MS, Angew. Chem. Int. Ed. 53, 14476–14479 (2014).