MULTIRESIDUE PESTICIDE ANALYSIS IN FRUITAND VEGETABLE COMMODITIES USING BOTH UPLC AND APGC ON A SINGLE MASS SPECTROMETER PLATFORM

Significance of the Topic

Ensuring reliable detection of multiple pesticide residues in fruits and vegetables is critical for food safety compliance with global MRL regulations. Rapid screening methods help regulatory bodies and industry laboratories monitor unauthorized or excessive pesticide use.

Study Objectives and Overview

This work aimed to develop a single analytical workflow on a unified triple quadrupole mass spectrometer platform, combining UPLC-MS/MS and GC-APCI-MS/MS (APGC) for the simultaneous determination of approximately 200 pesticides across diverse fruit and vegetable commodities.

Methodology

Sample Preparation and Cleanup employed a QuEChERS approach with dispersive SPE tailored by matrix:

• Celery, lemon and corn extracts: 150 mg MgSO4, 25 mg PSA, 7.5 mg GCB per 1 mL aliquot
• Kale extracts: 900 mg MgSO4, 150 mg PSA, 150 mg GCB per 6 mL aliquot

Chromatographic and MS/MS Conditions:

• UPLC-MS/MS: Waters ACQUITY UPLC H Class with BEH C18 column (2.1 × 100 mm, 1.7 µm); mobile phases water and methanol with 10 mM ammonium acetate; ESI+ ionization
• APGC-MS/MS: Agilent 7890A GC with Rxi-5MS column (30 m × 0.25 mm × 0.25 µm); proton-transfer ionization via universal source; Xevo TQ-S micro mass spectrometer
• Data acquisition using QuanPedia for method generation and TargetLynx processing; at least two MRM transitions per compound; fast scanning rates to maintain ≥12 points per peak

Instrumentation Used

A single Waters Xevo TQ-S micro triple quadrupole mass spectrometer equipped with a Universal Source supported both UPLC-ESI and GC-APCI analyses, enabling rapid inlet switching without hardware changes.

Main Results and Discussion

Calibration and Sensitivity:

• Matrix-matched standards prepared in celery, lemon, corn and kale across 0.001–0.050 mg/kg
• UPLC responses were linear (R² ≥ 0.995) while APGC responses required quadratic fitting for certain analytes
• Quantitation down to 0.010 mg/kg achieved for over 99 % of pesticides with residuals within ± 20 % of calibration points

Precision and Repeatability:

• RSDs < 10 % for > 90 % of compounds across both methods (n = 3); APGC in kale showed RSD < 10 % for > 80 % of analytes
• Mean scan repeatability RSD approximately 5.2 %

Matrix Interference Assessment:
RADAR full-scan experiments uncovered matrix enhancement effects, exemplified by tetrachlorvinphos interference in kale, guiding potential cleanup or chromatographic adjustments.

Benefits and Practical Applications

The dual-mode platform simplifies multi-residue pesticide testing by consolidating UPLC and GC methods on one instrument. Method generation via QuanPedia accelerates protocol development, and compliance with SANTE/11945/2015 ensures regulatory acceptance. High throughput supports routine QA/QC and regulatory monitoring.

Future Trends and Opportunities

Potential advancements include the integration of high-resolution accurate mass for non-target screening, machine learning algorithms to predict matrix effects, automated method optimization, expansion to additional matrices and analyte classes, and enhanced workflow automation for high-volume laboratories.

Conclusion

A universal tandem quadrupole approach combining UPLC-ESI and GC-APCI on the Xevo TQ-S micro delivers rapid, robust and regulatory-compliant multi-residue pesticide analysis, streamlining laboratory efficiency while maintaining high sensitivity, precision and throughput.

References

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3. Tienstra M, Portoles T, Hernandez F, Mol JGJ. Fast Gas Chromatographic Residue Analysis in Animal Feed Using Split Injection and Atmospheric Pressure Chemical Ionisation Tandem Mass Spectrometry. J Chromatogr A. 2015;1422.
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5. European Commission. Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticides Residues Analysis in Food and Feed (SANTE/11945/2015), Rev. 0, 2015.