Leave Interferences Behind With MS/MS

Importance of the Topic

The accurate determination of trace and ultratrace elements in complex matrices is crucial across industries such as semiconductors, environmental monitoring, life sciences, food safety, and geology. Interferences arising from polyatomic species, isobaric overlaps, and high dissolved solids often compromise the precision, accuracy, and detection limits of conventional quadrupole ICP-MS methods. The development of triple quadrupole ICP-MS with MS/MS capability addresses these challenges by offering superior interference removal, lower detection limits, and enhanced confidence in multi-element analyses.

Study Goals and Overview

This whitepaper introduces the second-generation Agilent 8900 triple quadrupole ICP-MS (ICP-QQQ) and its MS/MS capabilities. Key objectives include:

• Demonstrating interference removal by MS/MS reaction gas methods
• Evaluating detection limits for challenging elements (Si, S) at ppt levels
• Resolving direct isobaric overlaps in geochemistry and nuclear applications
• Extending single particle and nanoparticle characterization capabilities
• Assessing sample introduction and matrix tolerance improvements

Methodology and Instrumentation

The Agilent 8900 ICP-QQQ uses two mass-filter quadrupoles (Q1, Q2) separated by an octopole reaction cell (ORS4). In MS/MS mode Q1 selects the target m/z before the cell, ensuring that only the analyte and intentional product ions enter the cell. Reactive or collision gases (O₂, NH₃, He) then remove on-mass and polyatomic interferences. Q2 filters out residual interferences and by-products before detection by a dual-mode electron multiplier. This tandem setup achieves effective removal of unreactive interferences and prevents formation of new product ions from unwanted precursors.

Main Results and Discussion

• Detection Limits for Si and S
Using MS/MS with O₂ cell gas, detection limits below 10 ng/L for Si and below 6 ng/L for S were achieved. Controlled background and blank contributions (BECs) demonstrate reliable ppt-level performance.
• Isobaric Overlap Resolution
MS/MS reaction chemistry separated 204Hg from 204Pb, and Hf isotopes from Yb/Lu interferences, enabling accurate 176Hf/177Hf ratios. This performance rivals sector-field HR-ICP-MS without requiring ultra-high mass resolution.
• Nanoparticle and Single Particle Analysis
The 8900 supports fast time-resolved analysis (0.1 ms dwell) for single particle and cell ICP-MS. It reliably distinguishes 50 nm SiO₂ particles from dissolved background, enabling size distribution and particle counting at sub-50 nm scales.
• Matrix Tolerance and High-Throughput Introduction
Ultra High Matrix Introduction (UHMI) tolerates up to 25% total dissolved solids. Peltier-cooled, low-flow sample introduction with optional Advanced Valve System (AVS MS) and Automated Dilution System (ADS) supports routine, high-throughput analyses with reduced downtime and contamination.

Benefits and Practical Applications

• Improved Confidence – MS/MS delivers consistent interference removal and stable backgrounds for multi-element quantification.
• Lower Detection Limits – Reactive cell gases and MS/MS enable ppt-level analysis of previously inaccessible elements.
• Expanded Speciation – Integrated LC, GC, CE, IC, FFF interfaces allow direct elemental species analysis with heated, inert transfer lines.
• High-Resolution Performance – Selective gas chemistries resolve complex isobars without sector-field instruments.
• Nanomaterials and Single Cell – Fast transient detection and advanced software modules characterize nanoparticles and single cells by elemental content.
• Operational Efficiency – Automated software checks, preset methods, and IntelliQuant Star Rating QC streamline workflows.

Future Trends and Opportunities

• Broader adoption of single cell and multi-omic elemental mapping with faster data acquisition and AI-driven data interpretation
• Expansion of novel reaction gas chemistries to target emerging analytes and complex matrices
• Integration of cloud-based monitoring and predictive maintenance to maximize uptime and data integrity
• Development of miniaturized, field-deployable triple quadrupole ICP-MS systems for onsite environmental and industrial monitoring

Conclusion

The Agilent 8900 ICP-QQQ with MS/MS represents a significant advance in ICP-MS technology, combining robust interference removal, ultralow detection limits, high matrix tolerance, and versatile speciation and nanoparticle capabilities. Its performance extends the analytical reach of quadrupole instruments into applications previously reserved for high-resolution or specialized techniques, delivering reliable, high-confidence data across diverse fields.