Agilent ICP-MS Journal (August 2002 – Issue 13)

Significance of the topic

Inductively coupled plasma mass spectrometry with collision reaction cell technology has become a cornerstone for trace level and speciation analysis across environmental, biological and industrial matrices. The capacity to remove polyatomic interferences, maintain high sensitivity and integrate separation techniques transforms ICP MS into a versatile tool for routine and specialized laboratories.

Objectives and study overview

This issue presents a comprehensive review of the Agilent Octopole Reaction System design and performance alongside real world case studies. Key objectives include

• Explaining the operating principles of the Agilent ORS in reaction and collision modes
• Profiling high throughput environmental laboratories using ICP MS
• Demonstrating high accuracy speciation via HPLC ICP MS and isotope dilution
• Presenting enhancements in multi mode tuning and direct analysis of organic solvents
• Providing community updates and best practice tips from user meetings

Methodology and instrumentation

The Agilent 7500c ICP MS featuring the octopole reaction cell was operated in hydrogen reaction mode to remove plasma based polyatomic species and in helium collision mode with kinetic energy discrimination for generic interference removal. Separation of arsenic species utilized anion exchange HPLC coupled to ICP MS with ion pairing reagents and a cooled spray chamber. Isotope dilution mass spectrometry was implemented for organotin quantitation following microwave extraction. Direct solvent analysis employed a low flow concentric nebulizer and optional oxygen addition for stable plasma performance.

Main results and discussion

Hydrogen reactions achieved exponential attenuation of ArO interferences while maintaining analyte sensitivity. He mode with energy discrimination effectively removed unknown polyatomics in complex matrices without method adjustment. Laucks Testing Laboratories demonstrated over 30 element throughput in diverse environmental samples including high salt matrices. NARL achieved subpercent isotope ratio precision and participated successfully in international intercomparisons of tributyltin. The HPLC ICP MS method resolved seventeen arsenic species in marine biota within a single run enhancing metabolic and toxicity studies. Enhanced ChemStation multi tune functionality allowed acquisition of a single mass in multiple modes for unknown matrices. Direct analysis of pentane enabled ppb level determination of As Se and Hg without wet chemical preparation.

Benefits and practical applications

• Streamlined interference removal without element specific tuning
• High throughput and matrix tolerance for environmental QA QC
• Integrated speciation capabilities for food safety and biotoxicity
• Improved data robustness via isotope dilution and interlaboratory validation
• Operational efficiencies from automated mode switching and direct solvent analysis

Future trends and opportunities

Advances in reaction cell chemistries and kinetic energy discrimination will further reduce detection limits and expand to new isotope and molecular analysis. Tight integration of liquid and gas chromatographic separations and emerging hyphenations with tandem mass spectrometers promise enhanced speciation resolution and structural elucidation. High dynamic range detectors and intelligent automation will support real time quality control and unattended workflows, extending ICP MS into emerging fields such as metabolomics and process monitoring.

Conclusion

The combination of octopole reaction cell design, flexible gas modes and hyphenated separation techniques positions ICP MS as a leading technology for trace multielement and speciation analysis. Community engagement through user meetings and shared best practices continues to drive method innovation and practical adoption.

Reference

• Yamada N Takahashi J Sakata K The Effects of Cell gas Impurities and Kinetic Energy Discrimination in an Octopole Collision Cell ICP MS Under Non thermalized Conditions JAAS in publication
• Leonhard P Pepelnik R Prange A Yamada N Yamada T Analysis of Diluted Sea water at the ng L Level Using an ICP MS with an Octopole Reaction Cell J Anal At Spectrom 2002 17 189