NACRW: SUB 1μg/kg DETECTION OF GLYPHOSATE AND OTHER ANIONIC POLAR PESTICIDES USING A GENERIC EXTRACTION AND DETECTION BY LC-MS/MS

Importance of the Topic

Routine monitoring of anionic polar pesticides like glyphosate, AMPA and related metabolites is critical for food safety and regulatory compliance. Traditional single‐residue methods are laborious and time-consuming. The adoption of generic extraction strategies combined with sensitive LC-MS/MS detection addresses throughput and detection limit challenges in QA/QC, research and industrial laboratories.

Objectives and Study Overview

This study evaluates a generic QuPPe v12 extraction protocol coupled with the Xevo TQ Absolute mass spectrometer to achieve sub-µg/kg limits of quantification (LOQs) for ten anionic polar pesticides in representative wet (cucumber) and dry (wheat flour) matrices. Key aims include demonstrating method sensitivity, accuracy and repeatability across a wide concentration range.

Methodology and Instrumentation

The extraction procedure follows the QuPPe version 12 protocol for both high-water and dry commodities. Matrix standards were prepared from 0.5 to 200 µg/kg.

• Chromatography: ACQUITY UPLC I-Class PLUS system with Waters Anionic Polar Pesticide Column (2.1×100 mm, 5 µm), 0.9% formic acid in water and acetonitrile mobile phases, 10 µL injection, column at 50 °C.
• Mass spectrometry: Xevo TQ Absolute with electrospray ionisation in negative mode, MRM transitions optimized for each analyte, cone voltages and collision energies tuned for best sensitivity.

Main Results and Discussion

Limits of quantification of 0.5 µg/kg in cucumber and 2 µg/kg in wheat flour were achieved for most analytes (5 µg/kg LOQ for AMPA in wheat). Calibration curves over 0.25–100 ng/mL (cucumber) and 0.25–25 ng/mL (wheat) exhibited R² ≥ 0.99 and residuals below 20%. Accuracy (trueness) ranged from 89% to 117% with repeatability RSDs below 10% at both low and high concentration levels. Differences in LOQs reflect matrix dilution factors in QuPPe extraction for wet versus dry samples.

Benefits and Practical Applications

The combined generic extraction and high‐sensitivity MS approach enables multi-residue analysis of polar anionic pesticides in diverse food matrices with minimal sample cleanup. The Xevo TQ Absolute system allows lower injection volumes or improved detection limits, enhancing system robustness by reducing matrix load. This workflow supports high throughput screening and routine compliance testing.

Future Trends and Opportunities

Further development may focus on expanding the pesticide panel, automating QuPPe extraction, coupling with high-resolution MS or ion chromatography for even greater selectivity, and implementing data-driven analytics to streamline result review. Continuous improvements in column chemistry and MS sensitivity will drive lower detection thresholds and broader applicability across complex food and environmental matrices.

Conclusion

The integration of the QuPPe generic extraction protocol with the Xevo TQ Absolute mass spectrometer delivers robust, sensitive detection of anionic polar pesticides at sub-µg/kg levels in both wet and dry commodity matrices. This streamlined approach meets the needs of modern analytical laboratories for efficiency, reliability and regulatory compliance.

References

• Quick Method for the Analysis of Highly Polar Pesticides in Food of Plant Origin (QuPPe-PO Method) Version 12, EURL-SRM, 2021.
• Hird S, Adams S, De-Alwis J. Evaluation of a Method for Highly Polar Anionic Pesticides in Foodstuffs Using LC-MS/MS. Waters App Note 720007505, 2022.
• De-Alwis J et al. Interlaboratory Study on Anionic Polar Pesticides in Crops and Foodstuffs. Waters App Note 720007154, 2021.
• Kumar KP et al. Determination of Anionic Polar Pesticides in Grapes Using UPLC-MS. Waters App Note 720006925, 2020.
• Ross E et al. Determination of Anionic Polar Pesticides in High Water Foodstuffs. Waters App Note 720006645, 2019.