DETERMINATION OF PESTICIDE RESIDUES IN QUECHERS EXTRACTS OF FRUIT COMMODITIES BY GC-MS/MS

Significance of the Topic

Food safety regulations impose strict limits on pesticide residues in fruits and vegetables. Multiresidue analysis is essential for consumer protection and regulatory compliance, requiring methods that combine sensitivity, accuracy and high throughput to meet maximum residue limits across diverse commodity matrices.

Objectives and Study Overview

This study aimed to demonstrate a streamlined gas chromatography tandem mass spectrometry GC-MS/MS workflow for detecting a wide range of pesticides in QuEChERS extracts of fruit commodities. The method uses the CEN QuEChERS extraction, dispersive SPE cleanup and a new GC-MS/MS system to achieve low ppb quantitation in apple and raisin matrices.

Methodology and Instrumentation

The samples were prepared by CEN QuEChERS: 10 g of organic apple or 5 g of rehydrated raisin extracted with acetonitrile, salts and buffer, followed by d-SPE cleanup with PSA and MgSO4. Extracts were evaporated, reconstituted in ethyl acetate and spiked with pesticide standards. Analysis was performed on an Agilent 7890 GC with Rtx-5MS column (30 m x 0.25 mm x 0.25 µm) coupled to a Waters Xevo TQ-GC triple quadrupole. Electron ionization at 70 eV, pulsed splitless injection, MRM acquisition via the Quanpedia database ensured automated transition generation.

Results and Discussion

Automated MRM setup using Quanpedia facilitated rapid method development with minimal optimization. Calibration in apple and raisin showed excellent linearity (R2 > 0.993) between 0.001 and 0.100 mg/kg. Repeatability at three QC levels (n=5) yielded mean recoveries within 85-115 and RSD below 20. Sensitivity met SANTE 11813/2017 guidelines for MRL compliance.

Benefits and Practical Applications

The presented workflow offers high throughput multiresidue capability, robust quantitation at low ppb, and automated method setup. Laboratories can screen over 1000 pesticides across varied fruit matrices with confidence in regulatory and quality control scenarios.

Future Trends and Opportunities

Advances in database-driven MRM optimization and software automation will further reduce method development time. Integration of high-resolution MS and novel sample preparation formats may expand scope to more polar and thermally labile pesticides and enable multi-class analyses in complex matrices.

Conclusion

The GC-MS/MS method combined with QuEChERS extraction and d-SPE cleanup provides a reliable, sensitive and efficient solution for routine pesticide residue analysis in fruits. The use of the Xevo TQ-GC and automated MRM commissioning supports regulatory compliance and high laboratory throughput.

Used Instrumentation

• Sample Preparation: CEN QuEChERS extraction with PSA and MgSO4 d-SPE tubes
• Gas Chromatograph: Agilent 7890 GC
• Column: Rtx-5MS, 30 m x 0.25 mm x 0.25 µm
• Mass Spectrometer: Waters Xevo TQ-GC triple quadrupole
• Ionization: Electron impact 70 eV
• Acquisition Mode: MRM via Quanpedia database

References

1. European Commission (2016) EU Pesticide Database
2. EURL-FV (2018) Multiresidue Method using QuEChERS for Fruits and Vegetables
3. European Union (2017) SANTE 11813/2017 Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticide Residues