Thermo Scientific™ Orbitrap Exploris™ GC S Mass Spectrometer

Thermo Scientific Orbitrap Exploris GC S — Expert Summary

Importance of the topic

The analysis of persistent organic pollutants (POPs), dioxins, pesticides, and PFAS in food and environmental matrices requires ultra-trace sensitivity, high selectivity, robust uptime, and regulatory-grade data integrity. Modern high-resolution accurate-mass (HRAM) GC–MS solutions enable simultaneous screening, quantitation, and confirmation while supporting retrospective interrogation. Laboratories face growing demands for lower detection limits, broader compound scope, faster throughput, and streamlined compliance workflows; the Orbitrap Exploris GC S is presented as a platform designed to meet these requirements.

Objectives and overview of the system and study

This document presents the capabilities and workflows of the Thermo Scientific Orbitrap Exploris GC S mass spectrometer, emphasizing performance for dioxins (including dl‑PCBs), pesticides, PFAS, and emerging POPs. The aim is to demonstrate that a single GC‑Orbitrap platform can deliver the sensitivity, selectivity, robustness, and usability needed for routine and high‑throughput regulatory testing while enabling method consolidation and future scalability.

Used instrumentation

The platform components, sources, and software highlighted include:

• Thermo Scientific Orbitrap Exploris GC S mass spectrometer (HRAM Orbitrap analyzer; up to 60,000 resolving power at m/z 200).
• Advanced Electron Ionization (AEI) source with NeverVent capability (filament replacement and maintenance without venting).
• Advanced Quadrupole Technology (AQT) with isolation widths down to 0.4 Da, C‑Trap, and Advanced Active Beam Guide (AABG) to reduce neutrals entering quadrupole.
• Thermo Scientific TRACE 1600 Series GC with modular iConnect injectors/detectors.
• Thermo Scientific TriPlus RSH SMART autosampler (robotic sample handling and automated prep cycles, including online microSPE for QuEChERS cleanup).
• TRACE Dioxin column configured for dioxin/furan congener separation.
• Thermo Scientific Chromeleon Chromatography Data System with Dioxin HRAM eWorkflow and reporting templates, plus Compound Discoverer for unknown identification and retrospective analysis.
• Optional higher‑performance variant: Orbitrap Exploris GC 240 (up to 240,000 resolving power and MS/MS capability).

Methodology and workflows

Key method elements and laboratory workflows described:

• Ionization and acquisition modes: High‑stability EI using AEI; full‑scan HRAM acquisition; SIM HRAM options; CI and variable‑energy ionization available on some configurations; MS/MS available on higher‑end models.
• NeverVent maintenance: column changes, ion source cleaning, and filament replacement without venting the mass spectrometer to maximize uptime.
• Preconfigured software eWorkflows: Chromeleon Dioxin HRAM eWorkflow provides templates for method setup, system suitability, real‑time QC monitoring (13C standard recovery, ion ratios, TEQ), automated LOQ flagging, and regulation‑ready reporting (e.g., EPA 1613 implementation support).
• Sample preparation examples: QuEChERS extracts for pesticides (wheat, baby food spinach), fat matrices and fish oil for dioxins; matrix‑matched calibrations and use of 13C internal standards for quantitation.
• Data handling: full‑scan HRAM enables multi‑point identification (accurate mass, isotope pattern, retention index, library spectral matching) and retrospective interrogation without re‑running samples.

Main results and discussion

Performance highlights summarized from presented data and examples:

• Dioxin sensitivity and precision: Demonstrated detection at 10 fg on‑column for 2,3,7,8‑TCDD with consistent response across ~180 injections. Ion ratio compliance at ±15% was maintained across large batches, indicating regulatory‑suitable confirmation capability.
• Mass resolution and accuracy: Measured resolution for dioxin congeners exceeded the regulatory target of 10,000, with typical values near 20,000 at 5% peak height. Mass accuracy for pesticide ions shown routinely within tenths of ppm (e.g., <0.3 ppm), supporting reliable elemental composition assignment.
• Pesticide detection limits and repeatability: Distribution of calculated IDLs for hundreds of pesticides in QuEChERS extracts showed most analytes below a few pg on‑column (many <2.5 pg). Repeatability across diverse matrices at 10 µg/kg showed acceptable %RSD for many compounds, demonstrating robustness without internal standard correction.
• Spectral fidelity and library matching: Full‑scan HRAM spectra provided strong isotope cluster fidelity and high library match scores (forward/reverse), increasing confidence in identifications and enabling multiple identification points beyond single ion ratios.
• Comparability to sector HRMS: WHO‑PCDD/F‑TEQ results in food matrices compared favorably with traditional GC‑HRMS magnetic sector instrumentation, indicating the Orbitrap solution can meet regulatory quantitation performance.

Benefits and practical applications

The Orbitrap Exploris GC S platform offers several laboratory advantages:

• Single‑platform consolidation: Screening, quantitation, and confirmation workflows for POPs, pesticides, and PFAS can be run on one system, reducing instrument fleet complexity.
• Regulatory readiness: Preconfigured eWorkflows, system suitability checks, and automated reporting ease compliance with regulated methods (e.g., dioxin TEQ workflows).
• High uptime and maintainability: NeverVent source technology and modular TRACE GC components reduce downtime and simplify maintenance tasks.
• Flexible sample throughput and automation: TriPlus RSH autosampler and automated prep cycles (dilution, internal standard addition, microSPE cleanup) increase throughput and reproducibility.
• Retrospective analysis: HRAM full‑scan data supports later interrogation for emerging contaminants without additional injections.
• Wide dynamic range and linearity: Supports quantitation across broader concentration ranges within complex matrices.

Future trends and potential uses

Emerging directions and opportunities enabled by the platform include:

• PFAS analysis expansion: Quantitative workflows for volatile PFAS and discovery workflows to find novel PFAS species using HRAM full‑scan data.
• Higher resolving power and MS/MS for complex cases: Upgrading to 240,000 resolving power and MS/MS capability for the most challenging identification tasks and structural elucidation.
• Deeper unknown screening and non‑targeted discovery: Node‑based processing and statistical workflows (Compound Discoverer) for sample profiling, trend detection, and unknown identification in environmental and food surveillance.
• Greater automation and informatics integration: Laboratory automation, centralized CDS deployments, and AI‑assisted data review can accelerate throughput and decision quality in multi‑site operations.
• Method consolidation and regulatory adoption: Wider adoption of HRAM Orbitrap platforms could reduce dependence on traditional sector HRMS instruments for many regulated assays while maintaining data quality.

Conclusion

The Orbitrap Exploris GC S is positioned as a modern HRAM GC–MS solution that balances ultra‑trace sensitivity, high selectivity, and robust day‑to‑day operation for dioxins, pesticides, PFAS, and other POPs. Key enablers include the AEI NeverVent source for continuous operation, Orbitrap resolving power and mass accuracy for confident identification, and integrated software eWorkflows for regulatory compliance and rapid implementation. The system supports method consolidation, retrospective data mining, and scalable upgrades, making it suitable for food safety and environmental laboratories facing evolving analytical and regulatory challenges.

References

• Thermo Fisher Scientific. Orbitrap Exploris GC S: Product brochure and technical summary (2026).
• Thermo Fisher Scientific. Chromeleon Dioxin HRAM eWorkflow and TriPlus RSH SMART autosampler product materials (2026).