Rapid and Simple Approaches to Multi-residue Pesticide Analysis in Fruits and Vegetables on both GC-MS/MS and LC-MS/MS

Significance of the Topic

Rapid and accurate detection of multiple pesticide residues in fruits and vegetables is critical for food safety, regulatory compliance, and public health.
Combining efficient sample preparation with tandem mass spectrometry enables high-throughput monitoring of complex food matrices.

Goals and Study Overview

This study aimed to develop and demonstrate fast, simple protocols for multi-residue pesticide analysis on both GC-MS/MS and LC-MS/MS systems.
It evaluated an improved QuEChERS extraction, optimized MRM method development using Compound Based Screening (CBS), and assessed performance across vegetables with varying moisture and fat content.

Methodology

An enhanced QuEChERS extraction protocol was applied to rice, avocado, and spinach to represent low-moisture, high-fat, and high-water matrices.
Thirty pesticides were spiked into blank extracts for calibration and recovery tests.
Calibration solutions were prepared at 1–100 ppb for GC-MS/MS and 0.1–100 ppb for LC-MS/MS using matrix-matched standards.
The CBS workflow in Bruker MSWS 8.1 software automated target selection, timed-MRM scheduling, retention time updates, and quantifier/qualifier ratio calculations.

Used Instrumentation

• Bruker Scion GC-MS/MS with Scion 436 GC, electron ionization (EI), BR-5MS column (30 m × 0.25 mm, 0.25 µm), 36 min run time.
• Bruker EVOQ Elite LC-MS/MS with Advance UHPLC, electrospray ionization (ESI) positive mode, Phenomenex Synergi Hydro-RP column (100 mm × 2.0 mm, 2.5 µm), 14 min run time.

Results and Discussion

Both platforms achieved excellent linearity across calibration ranges (R2 > 0.99) in rice, avocado, and spinach matrices.
Sensitivity reached 5 ppb in spinach for GC-MS/MS and 1 ppb for LC-MS/MS; sub-ppb detection (0.1 ppb) was demonstrated on the LC-MS/MS system.
The automated CBS workflow significantly reduced method development time and ensured consistent MRM scheduling and ion ratio monitoring.

Benefits and Practical Applications

• The modified QuEChERS protocol provides a unified, cost-effective extraction suitable for both GC and LC analyses, reducing sample preparation steps.
• CBS automation simplifies MRM method creation, accelerates deployment in quality control and regulatory laboratories, and minimizes manual intervention.
• High sensitivity and broad linear range support reliable monitoring of low-level pesticide residues in diverse food matrices.

Future Trends and Opportunities

Integration of enhanced spectral libraries and machine learning algorithms may further automate multi-residue method development.
Expansion of QuEChERS adaptations for emerging analytes and non-traditional matrices (e.g., processed foods) could broaden applicability.
Development of miniaturized or field-deployable MS platforms may enable on-site screening for rapid decision-making.

Conclusion

The combined optimized QuEChERS extraction and CBS-based MRM workflow on GC-MS/MS and LC-MS/MS platforms delivers a robust, efficient solution for routine multi-residue pesticide analysis.
This approach enhances throughput, sensitivity, and method consistency, meeting the demands of modern food safety laboratories.

References

• Olusegun Ajayi et al., Rapid SPE Multiresidue Method for the Analysis of Polar and Nonpolar Pesticides in High Moisture Food Products. FDA/ORA/DFS, LIB#4495.
• Olusegun Ajayi et al., Los Angeles Micro Method: Rapid SPE Multiresidue Method for the Analysis of Polar and Nonpolar Pesticides in High Moisture Matrices, 2012 AOAC Conference Poster.