High Resolution Accurate Mass GC-MS based on Orbitrap Technology - A new chapter in GC-MS

Importance of the Topic

Gas chromatography mass spectrometry GC-MS has long been a cornerstone in analytical chemistry. The introduction of high resolution accurate mass HRAM using Orbitrap technology marks a significant advance, offering unprecedented selectivity, confidence in compound identification, and quantitative precision across complex matrices.

Objectives and Study Overview

• Introduce the Thermo Scientific Orbitrap GC-MS family
• Detail system architecture and HRAM benefits
• Assess analytical performance for targeted and untargeted workflows
• Demonstrate applications in food safety, environmental analysis, metabolomics, and more

Instrumentation

• Q Exactive GC system with Orbitrap mass analyzer
• Exactive GC system for routine analyses
• TRACE 1310 GC system with modular injector and detector
• ExtractaBrite ion source with patented RF lens and vacuum-free column replacement
• High-energy collision dissociation HCD fragmentation cell
• TraceFinder and Compound Discoverer software for data processing

Main Results and Discussion

• Resolving power up to 120 000 FWHM at m/z 200 enables clear separation of isobaric compounds
• Mass accuracy below 1 ppm across six orders of magnitude dynamic range without in-sequence recalibration
• Sensitivity down to low femtogram on-column detection and ppt levels in complex matrices
• Fast full-scan acquisition generating over 17 scans per narrow GC peak at RP 60 000
• Pesticides in baby food: 132 compounds quantified with IDLs below 2 ng/g, RSD around 6 %, and mass errors under 0.5 ppm
• Non-targeted screening identified over 2500 peaks in tap water, including iodinated disinfection by-products and novel contaminants
• Untargeted metabolomics in a rat model demonstrated biomarker discovery for post-mortem interval using multivariate analysis
• Drugs of abuse and leachable impurities characterized with high confidence in biological and material samples

Benefits and Practical Applications

• Enhanced selectivity and spectral fidelity boost identification certainty in complex samples
• Full-scan HRAM quantitation matches triple quadrupole sensitivity while enabling retrospective data mining
• Broader dynamic range facilitates simultaneous detection of trace and abundant analytes
• Streamlined workflows for targeted quantitation, suspected screening, and non-targeted discovery

Future Trends and Opportunities

• Expansion of non-targeted screening in environmental, food, and clinical fields
• Integration of advanced software tools and machine learning for automated spectral interpretation
• Development of high-throughput methods and microfluidic interfaces for rapid profiling
• Broader adoption of HRAM GC-MS in regulatory and quality assurance laboratories

Conclusion

Orbitrap-based GC-MS platforms deliver a new level of performance in both targeted and untargeted analyses, combining exceptional mass accuracy, resolving power, and sensitivity. These systems enable confident compound identification and robust quantitation across diverse applications, setting the stage for future analytical breakthroughs.

Reference

• Thermo Fisher Scientific Webinar High Resolution Accurate Mass GC-MS based on Orbitrap Technology, 25 November 2016