DIOXIN: Enhanced sensitivity in GC-MS/MS technology

Importance of the Topic

The demand for ultra-sensitive, reliable and high-throughput analytical methods has never been greater. Modern regulatory and research laboratories require lower detection limits, robust operation over extended sequences and simplified workflows to maximize productivity. Enhanced GC-MS/MS techniques meet these challenges by delivering trace-level quantification, reduced downtime and scalable solutions for diverse matrices.

Objectives and Study Overview

This whitepaper introduces the Thermo Scientific TSQ 9000 triple quadrupole GC-MS/MS system equipped with the Advanced Electron Ionization (AEI) source and NeverVent technology. The study aims to demonstrate:

• Attogram-range sensitivity for challenging analytes.
• Uninterrupted routine analysis with minimal maintenance.
• Ease of method development, from single quad to SRM workflows.
• Scalability to accommodate growing laboratory requirements.

Methodology and Used Instrumentation

The approach integrates several innovations:

• Advanced Electron Ionization (AEI) source with dual filaments, proprietary RF lenses and inert materials to maximize ionization efficiency and minimize contamination.
• Rapid collision cell (EvoCell) delivering 800 SRM transitions per second for high-capacity methods.
• NeverVent™ design enabling vent-free exchange of GC columns and ion sources.
• TRACE 1300 GC system with Instant-Connect modules for injector and detector interchangeability.
• Chromeleon™ CDS software featuring AutoSRM, Timed-SRM, SmartTune and eWorkflows for streamlined method development and daily operation.

Key Results and Discussion

Sensitivity tests demonstrate detection limits in the attogram range:

• Octafluoronaphthalene IDL below 0.4 fg on-column, corresponding to ~120 ag RSD.
• 2,3,7,8-TCDD detectable at 5 fg on-column, with an IDL RSD of ~580 ag.
• QuEChERS pesticide extracts achieved IDLs down to 0.05 pg on-column, seven-fold more sensitive than competitor data.
• Baby-food pesticide screen: over 60% of 211 compounds identified below 0.1 µg/kg and more than 90% below 0.5 µg/kg.

Robustness studies:

• AEI source endured 900 injections of acetonitrile QuEChERS extracts with <20% RSD for >90% of 150 monitored pesticides.
• PBDE repeatability across 320 fish matrix injections showed average RSD below 8% for all congeners.
• NeverVent column and source exchanges reduced downtime by up to 98%, enabling return to analysis in under five minutes.

Benefits and Practical Applications

The TSQ 9000 AEI system offers:

• Ultra-low detection limits for environmental, food-safety and dioxin analyses.
• Extended uptime and minimal maintenance through inert source materials and rapid exchange capabilities.
• High-throughput potential via compressed GC methods and high SRM speeds.
• User-friendly software tools for seamless migration from single quadrupole to triple quadrupole methods and automated tuning.
• Scalable configurations from entry-level to advanced NeverVent EI/CI setups to match budget and performance needs.

Future Trends and Possibilities

Ongoing developments may include:

• Further miniaturization of ion sources to push detection into the zeptogram range.
• Integration of machine-learning algorithms for predictive maintenance and automated method optimization.
• Expansion of rapid collision cell capabilities to support even greater transition densities and faster chromatographic gradients.
• Cloud-based data management and cross-platform interoperability for multi-technique laboratories.

Conclusion

The TSQ 9000 GC-MS/MS system with AEI source and NeverVent technology achieves unprecedented sensitivity, robustness and ease of use. It addresses the most demanding trace-level analyses while offering scalable, future-proof configurations and intuitive software workflows. Laboratories can confidently achieve lower detection limits, higher throughput and reduced downtime to meet evolving analytical challenges.

Used Instrumentation

• Thermo Scientific TSQ 9000 Triple Quadrupole GC-MS/MS with Advanced Electron Ionization source
• EvoCell Rapid Collision Cell Technology
• Thermo Scientific TRACE 1300 Series GC with Instant-Connect modules
• Chromeleon™ Chromatography Data System with AutoSRM, Timed-SRM and SmartTune