What is the benefit of high mass resolving power on the Orbitrap Exploris GC Series?

Importance of High-Resolution GC-MS Analysis

High mass resolving power and sub-ppm accuracy on GC-MS instruments such as the Orbitrap Exploris GC Series provide critical advantages for resolving analytes from matrix interferences and coeluting compounds. This ensures confident compound identification, narrow mass extraction windows, and retrospective data analysis capabilities that are essential for targeted and untargeted workflows in environmental, food safety, and forensic laboratories.

Objectives and Overview

This product spotlight evaluates the performance and benefits of the Thermo Scientific Orbitrap Exploris GC 240 mass spectrometer. It highlights how high-resolution accurate-mass (HR/AM) acquisition improves selectivity, sensitivity, and mass accuracy for volatile and semi-volatile small molecules. The study reviews resolving power up to 240,000 across the 50–600 Da scan range and demonstrates real-world examples of compound separation and matrix interference mitigation.

Used Instrumentation

• Thermo Scientific Orbitrap Exploris GC 240 Mass Spectrometer, hybrid quadrupole-Orbitrap system
• Gas chromatography interface optimized for volatile small molecules

Methodology

Full-scan HR/AM data were acquired over m/z 50–600 at resolving powers of 15,000, 30,000, 60,000, 120,000, and 240,000 (FWHM at m/z 200). Samples included QuEChERS leek extract spiked with chlorpropham and mixtures of flurenol methyl ester (m/z 240.0781) and dimetilan (m/z 240.1217). Narrow mass extraction windows (<±5 ppm) were applied to evaluate mass accuracy and selectivity under different resolution settings.

Main Results and Discussion

• Resolution versus m/z: Maximum resolving power reaches 240,000 at low m/z, decreasing toward higher masses but maintaining >30,000 across the scan range, aligning with typical volatile analytes.
• Matrix Interference Example: At 15K and 30K, chlorpropham could not be fully separated from isobaric matrix ions in leek extract, leading to mass errors up to 18.4 ppm. At 60K and above, the pesticide is resolved with mass errors <0.5 ppm.
• Compound Pair Separation: Flurenol methyl ester and dimetilan, differing by 0.0436 Da, are baseline resolved at all tested resolutions. Higher resolving power further improves peak shape and mass accuracy, supporting confident identification even at a 10:1 intensity ratio.

Benefits and Practical Applications

• Enhanced Selectivity: Narrow extraction windows reduce false positives and improve detection in complex matrices.
• Expanded Analytical Scope: Full-scan HR/AM data enable targeted quantitation, suspect screening, and non-target profiling in a single run.
• Retrospective Analysis: Complete high-resolution datasets can be reprocessed for new targets without additional experiments.
• Structural Elucidation: Accurate isotopic patterns and mass defects facilitate elemental composition proposals.

Future Trends and Applications

Advances in GC-MS technology will drive integration with AI-based data processing, automated annotation workflows, and further miniaturization for mobile or field-based analysis. Increasing scan speeds and resolving power will extend the technique to emerging contaminants, complex biological samples, and high-throughput screening demands.

Conclusion

The Orbitrap Exploris GC 240 mass spectrometer offers unmatched resolving power and sub-ppm mass accuracy for GC-amenable compounds, enabling confident identification, quantitation, and discovery across diverse analytical workflows. Its compact design and energy-efficient operation support sustainable laboratory practices while expanding analytical capabilities.

References

1. Thermo Fisher Scientific. Orbitrap Exploris GC 240 Mass Spectrometer Brochure; 2024.
2. Thermo Fisher Scientific. Orbitrap Exploris GC 240 Product Specifications; 2024.
3. Thermo Fisher Scientific. Technical Note 10730: Mass Resolving Power of 240,000 for Confident Compound Identification; 2024.
4. Thermo Fisher Scientific. White Paper 003116: Accelerating Research with Orbitrap Exploris GC 240; 2024.