Breakthrough performance of the Orbitrap Exploris GC for analytical testing and scientific research applications

Significance of the Topic

Gas chromatography–high resolution mass spectrometry is essential for sensitive detection and confident identification of trace analytes in complex matrices.

Objectives and Study Overview

The study evaluates the Orbitrap Exploris GC’s performance for analytical testing and scientific research, focusing on dynamic range, sensitivity, scan speed, mass accuracy, spectral fidelity, library matching, positive chemical ionization confirmation and resolving power.

Methodology and Instrumentation

The Orbitrap Exploris GC (including the 240 model) was coupled to a TRACE 1310 GC and TriPlus RSH autosampler. Electron ionization at 60 000 resolution (FWHM at m/z 200) was used, with positive chemical ionization (methane) for confirmation. Calibration used PFTBA, and lock-mass correction relied on siloxane column bleed. Sample preparations included dilution of MegaMix and pesticide standards, and QuEChERS extraction of flour and oats for matrix-matched analyses.

Main Results and Discussion

• Scan speed: Achieved 15 points across a 2.3 s peak, ensuring accurate integration and reproducible spectra.
• Library matching: NIST forward/reverse scores >890 for aldrin; consistent high scores for 142 pesticides in flour matrices.
• Dynamic range: Linear response over six orders of magnitude (0.1–10 000 pg on column) with R²>0.999 and repeatability (%RSD) of 1.0–4.9%.
• Sensitivity: Instrument detection limits averaged 0.7 pg on column (range 0.18–2.45 pg) for 142 pesticides spike-tests, with excellent repeatability.
• Spectral fidelity: Sub-ppm mass accuracy maintained at low (1 pg) and high (500 pg) levels, preserving isotopic cluster integrity in complex matrix.
• Mass accuracy: Average error of −0.2 ppm across 10 injections; 140 injections over two days yielded <1.1 ppm error without recalibration.
• Resolving power: At 240 000 resolution, matrix interferences were fully separated from target ions, improving mass accuracy from −6 ppm (30 k) to <1 ppm.
• PCI confirmation: Methane PCI produced [M+H]+, [M+C2H5]+ and [M+C3H5]+ adducts with <1 ppm accuracy, confirming elemental compositions.

Benefits and Practical Applications

High-resolution accurate-mass GC-MS workflows enable robust screening, identification and quantification of trace contaminants and unknowns in regulatory, food safety and environmental laboratories.

Future Trends and Possibilities

Advances in data analytics, expanded spectral libraries and integration with metabolomics platforms will extend the capabilities of high-resolution GC-MS to new applications in trace pollutant monitoring, biomarker discovery and real-time screening.

Conclusion

The Orbitrap Exploris GC delivers unparalleled dynamic range, sensitivity, mass accuracy, resolving power and spectral fidelity in full-scan acquisition, supporting demanding analytical testing and research without frequent maintenance.

Used Instrumentation

• Orbitrap Exploris GC and Exploris GC 240
• Thermo Scientific TRACE 1310 Gas Chromatograph
• TriPlus RSH Autosampler
• PFTBA for tuning and calibration

Reference

• The Power of High Resolution Accurate Mass Using Orbitrap Based GC-MS. Thermo Scientific White Paper 10456 (2015).
• Fast Screening, Identification, and Quantification of Pesticide Residues in Baby Food Using GC Orbitrap MS Technology. Thermo Scientific Application Note 10449.