Evaluation of the Performance of a Method for the Determination of Highly Polar, Anionic Pesticides in Foodstuffs Using LC-MS/MS

Importance of the Topic

Highly polar and anionic pesticides are not readily analyzed by traditional multiresidue methods. Effective monitoring of these compounds is critical to ensure food safety and regulatory compliance. The combination of QuPPe extraction and specialized LC-MS/MS separation addresses this analytical gap.

Objectives and Study Overview

The study evaluated the performance of an LC-MS/MS protocol for quantifying ten highly polar, anionic pesticide residues and metabolites across four food matrices: cucumber, rice, soybean, and milk. Spike recovery, repeatability, and detection limits were assessed to confirm suitability for compliance testing and due diligence analysis.

Methodology and Instrumentation

The method uses QuPPe extraction with acidified methanol, followed by chromatographic separation on a Waters Anionic Polar Pesticide column. Quantification is performed on a triple quadrupole mass spectrometer with multiple reaction monitoring. Matrix-matched calibration and stable isotope internal standards ensure accurate quantitation across diverse commodities.

Used Instrumentation

• ACQUITY UPLC H-Class PLUS system with FTN sample manager
• Xevo TQ-S micro tandem quadrupole mass spectrometer
• Anionic Polar Pesticide (APP) column based on BEH/DEA chemistry

Main Results and Discussion

Recovery of analytes ranged from 78 to 92% across all matrices, with repeatability (RSDr) between 0.4 and 6.4%. Linearity in matrix-matched calibration curves achieved R² > 0.99. Chromatographic performance showed stable peak shapes and retention over four days. One exception was AMPA in soybean, where signal suppression impaired quantification, suggesting further dilution for that matrix.

Benefits and Practical Applications

• No derivatization or ion-pair reagents required, simplifying workflow.
• Reliable quantitation below typical maximum residue limits (MRLs).
• Suitable for both official control laboratories and due diligence testing by food business operators.
• Outcome-based support model facilitates global implementation.

Future Trends and Opportunities

Further expansion of this approach may include additional commodity validation and low-level screening for emerging polar pesticides. Integration with high-throughput workflows and advanced data processing algorithms could enhance routine laboratory capacity and regulatory compliance efficiency.

Conclusion

The evaluated LC-MS/MS method combining QuPPe extraction and APP column separation provides a robust, sensitive, and reproducible platform for monitoring highly polar, anionic pesticides in food. Its validated performance across multiple matrices supports its adoption in routine residue analysis and compliance screening.

References

• Anastassiades M et al. Quick Method for the Analysis of Numerous Highly Polar Pesticides in Food Involving Extraction with Acidified Methanol and LC-MS/MS Measurement (QuPPe-PO-Method v12), Food of Plant Origin, 2021.
• Waters Application Note 720006645EN. Determination of Anionic Polar Pesticides in High Water Foodstuffs, 2019.
• Waters Application Note 720007154EN. Evaluation of the Performance of an LC-MS/MS Method for the Determination of Anionic Polar Pesticide Residues, 2021.
• European Commission. SANTE/12682/2019 Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticide Residue Analysis in Food and Feed, 2019.