Routine Pesticide Screening Solution: Data Independent Acquisition with a New LC/Q-TOF and Dedicated Screening Software

Importance of the Topic

Reliable detection of pesticide residues in food products is critical for consumer safety and regulatory compliance. As the list of regulated chemicals grows and diverse food matrices are analyzed daily, robust screening workflows with high sensitivity, specificity, and throughput are essential.

Study Objectives and Overview

The study aimed to develop and demonstrate a routine screening solution for over 200 pesticides in complex food matrices. The workflow combines data independent acquisition (DIA) on a high-resolution LC/Q-TOF system with a dedicated screening software to enable confident target and retrospective non-target analyses.

Methodology and Instrumentation

Sample Preparation and Acquisition

• An organic broccoli matrix was homogenized and extracted using QuEChERS for pigmented fruits and vegetables.
• Extracts were spiked with a 200-pesticide standard mixture at eight concentration levels (0.625–100 ppb) plus four heavy-labelled standards at 50 ppb (n=6).
• Reverse-phase separation was performed on an Agilent 1290 Infinity II LC.
• All Ions DIA acquisition was conducted in positive and negative modes with stepped collision energies of 20 and 40 eV, and reference ions were used for continuous mass accuracy correction.

Used Instrumentation

• Agilent 1290 Infinity II ultra-high-performance liquid chromatograph.
• Agilent Revident LC/Q-TOF with thermally controlled flight tube and new detector for extended dynamic range and mass stability.
• MassHunter Quantitative Analysis 12 Screener software featuring the SureMass feature detection algorithm.

Main Results and Discussion

Performance metrics demonstrated:

• Mass accuracy within ±2 ppm for over 200 analytes across 48 injections over 18 hours.
• Abundance precision with %RSD <20% for >99% of target compounds at 5 ppb and 10 ppb levels.
• Linear calibration curves (R² ≥ 0.99) from 0.625 to 100 ppb.
• Detection of 214 compounds including separation of five isomeric pairs in the standard mix.

The DIA approach provided both molecular and fragment ion information, enabling confident identification, data visualization, and retrospective suspect screening without requiring method stoppage for maintenance.

Benefits and Practical Applications

This workflow offers:

• High-throughput routine screening of regulatory and emerging pesticides in food matrices.
• Retrospective analysis of previously acquired data to address new contaminants of concern.
• Flexible library-driven screening that adapts to varying levels of reference information, supporting suspect prioritization without standards.
• User-friendly interface for rapid review of sample summaries, chromatograms, and fragment coelution scores.

Future Trends and Opportunities

Advances to watch include

• Expansion of curated spectral libraries and predictive retention time models for suspect screening.
• Integration of machine learning algorithms to automate feature detection and reduce false positives.
• Higher multiplexing capabilities and ultra-high-throughput workflows for large-scale food safety monitoring.
• Cloud-based data management for collaborative method development and regulatory reporting.

Conclusion

The combination of an advanced LC/Q-TOF platform, data independent acquisition, and specialized screening software delivers a robust, precise, and adaptable solution for routine pesticide residue analysis in complex food matrices, meeting regulatory demands and enabling future method expansions.

References

1. Yannell CE, Simmermaker C, et al. Enhanced Food Safety Testing: A Pesticide Screening Methodology Using the Agilent 6546 LC/Q-TOF and MassHunter Quantitative Analysis Software 10.0 LC/Q-TOF Screener Tool. Agilent Technologies Application Note 5994-0738EN, 2019.
2. European Commission. Analytical Quality Control and Method Validation Procedures for Pesticide Residues Analysis in Food and Feed. SANTE/11312/2021.