Simultaneous screening and quantification of pesticide residues in potato using GC-Orbitrap MS

Importance of the Topic

The presence of pesticide residues in potatoes poses significant risks to consumer health and international trade. Monitoring these residues at trace levels is essential for compliance with regulatory limits set by the European Commission and the Food Safety and Standards Authority of India. High-resolution accurate mass spectrometry enables both targeted screening and non-targeted retrospective analysis, improving selectivity and reducing false negatives in complex food matrices.

Objectives and Study Overview

This work aimed to establish a single method for simultaneous screening and quantification of over 197 pesticides in potato using a QuEChERS extraction followed by gas chromatography coupled to Orbitrap mass spectrometry. Method performance was benchmarked against SANTE/12682/2019 guidance and MRL requirements from EU and FSSAI.

Methodology and Instrumentation

Sample preparation employed the EN 15662 citrate-buffered QuEChERS protocol and an alternative AOAC 2007.01 approach. Extracts in acetonitrile were directly analyzed without solvent exchange. Instrumental analysis used a Thermo Scientific TRACE 1310 GC with TriPlus RSH autosampler, a TraceGOLD TG-5SIL MS column, and an Exactive GC Orbitrap MS operated in full scan mode at 60 000 resolving power over m/z 50–550. Data acquisition and processing were carried out in TraceFinder software with user-defined filters for retention time, mass error, linearity, recovery and precision.

Results and Discussion

Linearity in matrix-matched standards ranged from 0.001 to 0.1 mg/kg with R2 values greater than 0.99 and RF RSD below 10%. Limits of identification reached as low as 0.0005 mg/kg for many analytes and LOQ was set at 0.005 mg/kg, achieving recoveries between 76% and 116% with repeatability below 13%. Mass accuracy for 94% of compounds was within ±1 ppm and ion ratios remained within ±30% over 35 injections. Matrix effects varied but were effectively compensated by matrix-matched calibration and high-resolution extraction of target ions.

Benefits and Practical Applications

• Rapid multi-residue screening and quantification in a single run
• High selectivity reduces interference and false negatives
• Retrospective analysis capability for non-target compounds
• Compliance with EU and FSSAI MRLs in potato and other matrices
• Simplified workflow without the need for solvent exchange

Future Trends and Opportunities

Advances in high‐resolution mass spectrometry will drive non‐targeted screening of unknown contaminants and metabolites. Integration with machine learning and AI will enhance data interpretation and automation of quality control. Development of universal extraction methods and streamlining calibration strategies will further improve throughput. Harmonization of global regulatory guidelines will expand adoption of HRAM approaches in food safety laboratories.

Conclusion

The combined QuEChERS GC-Orbitrap method delivers robust, sensitive and high-throughput screening and quantitation of pesticide residues in potatoes. It meets stringent regulatory criteria for accuracy, precision and detection limits, offering a reliable solution for routine monitoring and research applications.

References

• SANTE 12682 2019 Guidance document on analytical quality control and method validation for pesticide residues
• EN 15662 QuEChERS method for pesticide residues analysis in food of plant origin
• AOAC Official Method 2007.01 Pesticide residues by acetonitrile extraction