Routine Quantitative Method of Analysis for Pesticides using GC Orbitrap Mass Spectrometry in accordance with SANTE/11945/2015 Guidelines

Significance of Pesticide Residue Analysis

International trade and year-round availability of fruits and vegetables create challenges for regulatory laboratories tasked with enforcing maximum residue levels. The SANTE/11945/2015 guidance defines strict criteria for method validation and analytical quality control to ensure data reliability in official controls and consumer exposure assessment.

Objectives and Study Overview

This study evaluated the performance of a full-scan GC Orbitrap high-resolution mass spectrometer for routine quantitation of 51 GC-amenable pesticides in tomato, leek and orange matrices. The key goals were to demonstrate compliance with SANTE requirements for limits of identification, linearity, repeatability and mass accuracy while simplifying acquisition settings and enabling retrospective data mining.

Methodology and Sample Preparation

Pesticide standards were spiked into blank extracts from homogenized samples prepared by citrate-buffered QuEChERS. Ten-point matrix-matched calibration curves (0.5–500 µg/kg) were established in each matrix. Replicate injections at 10 µg/kg assessed precision and long-term stability, with leek serving as a high-complexity challenge.

Instrumentation

• Exactive GC Orbitrap mass spectrometer (60 000 FWHM at m/z 200, EI full-scan).
• TRACE 1310 gas chromatograph with TraceGOLD TG-5SilMS 30 m × 0.25 mm × 0.25 µm column and split/splitless inlet.
• Thermo Scientific TriPlus RSH autosampler.
• TraceFinder software for acquisition, processing and reporting with accurate-mass compound database.

Main Results and Discussion

• Limits of identification were ≤ 2 µg/kg for 79 % of pesticide/matrix pairs; limits of detection were ≤ 1 µg/kg for 93 % of combinations.
• Linearity across 0.5–500 µg/kg yielded R² > 0.99 in all matrices.
• Peak area repeatability at 10 µg/kg showed RSD < 10 %, exceeding the SANTE target of 20 %.
• Mass accuracy remained < 1 ppm across the full concentration range, maintained by automatic gain control to prevent detector saturation.
• High resolving power (60 000 FWHM) effectively resolved co-eluting matrix interferences, securing confident identification and quantitation.
• Extended testing (100 injections over 66 hours) demonstrated stable sensitivity and mass measurement without intermediate maintenance.

Benefits and Practical Applications

This full-scan HRMS approach eliminates the need for scheduled ion monitoring, increases scope for multi-residue screening, and allows retrospective interrogation for emerging contaminants. Its selectivity, sensitivity and robust mass accuracy support regulatory compliance, enforcement and risk assessment workflows.

Future Trends and Potential Applications

Advances in high-resolution MS, artificial intelligence-driven data processing and cloud connectivity will further enhance non-targeted screening capabilities. Integration of spectral libraries, isotope pattern recognition and automated quality control is expected to streamline routine pesticide residue analysis and adapt to evolving regulatory landscapes.

Conclusion

The Exactive GC Orbitrap system meets SANTE/11945/2015 guidelines for routine pesticide analysis, delivering sub-ppm mass accuracy, excellent sensitivity and precision across complex matrices. Full-scan acquisition simplifies method management and future-proofs laboratories for comprehensive and retrospective screening.

References

1. European Commission Regulation (EC) No. 396/2005 on maximum residue levels of pesticides in or on food and feed.
2. Directive 91/414/EEC concerning the placing of plant protection products on the market.
3. SANTE/11945/2015 Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticide Residues Analysis in Food and Feed.
4. Kellmann M. et al., Full Scan MS in Comprehensive Qualitative and Quantitative Residue Analysis in Food and Feed Matrices: How Much Resolving Power is Required? J. Am. Soc. Mass Spectrom., 2009, 20, 1464–1476.
5. Belmonte Valles N. et al., Determination of chlorothalonil in difficult-to-analyse vegetable matrices using various multiresidue methods. Analyst, 2012, 137, 2513–2520.
6. Mol H.G.J. et al., Evaluation of gas chromatography-electron ionization full scan high-resolution Orbitrap mass spectrometry for pesticide residue analysis, Analytica Chim. Acta, 2016, doi:10.1016/j.aca.2016.06.017.