An Assessment of GC Orbitrap MS Technology for the Routine Screening and Quantification of Pesticide Residues in Food

Significance of the Topic

Pesticide residue monitoring in fruits and vegetables is essential for consumer safety and compliance with international regulations. High-resolution full-scan gas chromatography mass spectrometry offers the potential for broad screening capabilities, superior selectivity and confident identification of regulated compounds at low concentration levels.

Goals and Study Overview

This work evaluates the performance of a high-resolution Orbitrap mass spectrometer coupled to gas chromatography for routine screening and quantification of 51 pesticides in complex food matrices. The study follows established European guidance for method validation and seeks to demonstrate robustness, sensitivity and long-term repeatability for routine laboratory use.

Materials and Methods

The analytical workflow employs a QuEChERS extraction for tomato, leek and orange samples, followed by ethyl acetate reconstitution of matrix blanks spiked with pesticides. Calibration standards cover 0.5 to 500 µg per kilogram, with test injections at 10 µg per kilogram and 100 repeat injections for repeatability assessment.

Instrumentation Used

• Gas chromatograph: TRACE 1310 GC with single taper liner and helium carrier gas
• Mass spectrometer: Exactive GC Orbitrap system with electron ionization at 70 electronvolts
• Acquisition: full-scan mode at 60 000 resolving power (full width half maximum) over 50 to 550 m/z
• Data processing: TraceFinder software for automated identification, quantification and quality flags

Main Results and Discussion

All 51 pesticides were detected and confirmed at levels below 5 µg per kilogram and 93 percent were quantified at or below 1 µg per kilogram in accordance with regulatory guidelines. Mass accuracy remained below 1 part per million across six orders of magnitude in concentration, with resolving power ensuring interference-free detection. Repeatability tests of 100 sequential tomato injections over 66 hours showed consistent peak areas and sub-1 ppm mass accuracy, and percent relative standard deviations below 6 percent. Ten replicate injections in three matrices at 10 µg per kilogram yielded RSD values below 10 percent, well within the 20 percent threshold.

Practical Benefits and Applications

• Comprehensive full-scan acquisition enables retrospective data analysis for non-target compounds.
• High resolving power and sub-ppm accuracy enhance confidence in trace-level identifications.
• Robust repeatability and resistance to detector saturation support high-throughput routine testing.
• Automated software workflows accelerate data review, flagging and reporting for regulatory compliance.

Future Trends and Potential Applications

Advances in high-resolution mass spectrometry will further expand non-target and suspect screening capabilities for emerging contaminants. Integration with machine learning algorithms may streamline data interpretation, while miniaturized or portable formats could enable on-site screening in supply chains. Ongoing developments in software automation are expected to reduce analyst workload and improve laboratory throughput.

Conclusion

The Exactive GC Orbitrap mass spectrometer demonstrates the selectivity, sensitivity and long-term stability required for routine pesticide residue analysis in food matrices. Its full-scan high-resolution capabilities meet regulatory performance criteria and provide a flexible platform for comprehensive screening.

Reference

1. SANTE119452015 Guidance document on analytical quality control and method validation procedures for pesticides residues analysis in food and feed implemented 2016
2. Belmonte Valles N, Retamal M, Martinez-Uroz MA, Mezcua M, Fernandez-Alba AR, de Kok A Determination of chlorothalonil in difficult-to-analyse vegetable matrices using various multiresidue methods Analyst 137 2012 p 2513–2520