NACRW 2017: Two Years On: The Impact of Orbitrap™ GC-MS in Food Analysis

Importance of the topic

Food analysis demands accurate detection of contaminants and adulterants at trace levels. Orbitrap GC-MS offers ultra-high resolution and mass accuracy to enhance confidence in compound identification and quantification across diverse food matrices.

Study objectives and overview

This review examines two years of application data for Orbitrap GC-MS in food analysis, covering pesticide residues, persistent organic pollutants, food contact materials, and product authenticity. It highlights performance metrics, methodological advantages, and practical outcomes of high-resolution accurate-mass (HRAM) GC-MS.

Methodology and instrumentation

Orbitrap GC-MS systems integrate gas chromatography with an Orbitrap mass analyzer capable of resolving power up to 120,000 FWHM at m/z 200 and mass accuracy below 1 ppm. Ionization modes include electron ionization (EI) at 70 eV and chemical ionization (CI). Key instruments:

• Q Exactive GC Orbitrap GC-MS/MS: full-scan, timed-SIM and MS/MS capability
• Exactive GC Orbitrap GC-MS: full-scan and timed-SIM

Main results and discussion

Pesticide residues:

• Limits of detection comparable to triple quadrupole systems at low ppt levels in fruit and vegetable matrices.
• Full-scan HRAM enables simultaneous quantitative determination and broad-spectrum non-target screening.

Persistent organic pollutants (chlorinated paraffins, PBDEs):

• High resolution (60,000–120,000) resolved isomers in complex CP mixtures without chromatographic separation.
• Negative chemical ionization provided linear responses (25–5 000 ppb) with R2>0.9996 for C10–C13 homologues.
• PBDE analysis achieved quantification at 0.01 ng/g with excellent sensitivity and selectivity in complex matrices.

Food contact materials:

• High-resolution full-scan and fragmentation modes identified non-intentionally added substances (NIAS) using accurate mass matching and HRF scores above 95%.
• Examples include α-tocopherol acetate and various acrylate monomers confirmed by precursor and fragment masses within sub-ppm error.

Authenticity testing:

• Comprehensive volatile profiling of whiskies differentiated production methods and aging using principal component analysis.
• Mass accuracy below 1 ppm and high spectral quality improved discrimination of major and minor components.

Benefits and practical applications

Orbitrap GC-MS offers:

• Ultra-high resolving power and mass accuracy for unambiguous compound identification.
• Sensitivity comparable to triple quadrupole instruments in full-scan mode.
• Simultaneous targeted quantification and non-targeted screening in a single analysis.
• Potential for reduced sample preparation and faster workflows for persistent organic pollutants.

Future trends and potential applications

Anticipated advances include real-time data processing, expanded non-target spectral libraries, multi-residue methods combining diverse contaminants, and enhanced software automation for streamlined data interpretation.

Conclusion

Orbitrap GC-MS has proven transformative for food analysis, delivering robust performance across multiple applications. Its combination of high resolution, mass accuracy, and versatile scan modes supports routine and advanced testing for food safety, quality, and authenticity.

References

Mol HGJ, Tienstra M, Zomer P. Evaluation of gas chromatography-electron ionization-full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis. Anal Chim Acta. 2016;
Ucles S, Lozano A, Martínez-Bueno MJ, Fernandez-Alba AR. Shifting the paradigm in gas chromatography mass spectrometry pesticide analysis using high resolution accurate mass spectrometry. J Chromatogr A. 2017;
Krätschmer K, et al. High resolution accurate mass screening for chlorinated paraffins in food samples using GC-Orbitrap mass spectrometry. Dioxin. 2017;
Martínez-Bueno MJ, Hernando MD, Uclés S, Rajski L, Cimmino S, Fernández-Alba AR. Identification of non-intentionally added substances in food packaging nanofilms by gas and liquid chromatography coupled to Orbitrap mass spectrometry. Talanta. 2017;172:68–77;
Cortés-Francisco N. Practical experiences of implementing POPs methods using Orbitrap GC-MS. BFR. 2017;
Hajslova J, Pulkrabova J, Stupák M. Comprehensive chemical profiling of whiskies using Q Exactive GC. RAFA. 2016