Targeted and Untargeted Analysis of Pesticides and Other Contaminants in Fruits and Vegetables Using Multi-Platform GC-MS/MS and GC/Q-TOF

Importance of the Topic

Ensuring the safety and quality of fruits and vegetables requires sensitive detection of trace-level pesticide residues and other contaminants. Advances in gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and high-resolution GC/Q-TOF now deliver comprehensive workflows combining targeted quantitation and broad-spectrum screening. This multi-platform approach streamlines analysis in complex food matrices, supports regulatory compliance, and enhances public health protection.

Objectives and Study Overview

This work demonstrates a complete analytical workflow for both targeted and untargeted assessment of pesticides and other contaminants in fruits and vegetables. Key goals include:

• Integrating triple quadrupole GC-MS/MS for sensitive quantification of predefined analytes.
• Employing high-resolution GC/Q-TOF for full-spectrum accurate-mass screening and identification.
• Establishing a consistent retention time-locked method across platforms.

Methodology and Instrumentation

A QuEChERS-based extraction provided rapid cleanup and extraction compatible with both GC-MS platforms. Chromatographic separation used a 15 m HP-5MS UI column under a 20 min retention time-locked program. Instrument configurations:

• GC-Q/TOF: Agilent 7890 GC with 7200 high-resolution Q-TOF, mid-column backflush.
• GC-MS/MS: Agilent 7890 GC with 7010 triple quadrupole MS/MS operating in electron impact (EI) mode.

Injection: 1 µL cold splitless at 280 °C. Transfer line and interface maintained at 280 °C, ion source at 300 °C. Q-TOF acquired 45–550 m/z at 5 spectra/s. Data processed using Agilent MassHunter with SureMass, PCDL for targeted screening and NIST library for untargeted analysis.

Main Results and Discussion

The multi-platform workflow enabled efficient screening and quantification:

• Targeted GC/Q-TOF screening identified over 60 spiked pesticides (10 ng/mL) across various produce matrices with retention time precision below 0.01 min and mass errors under 5 ppm.
• Untargeted library searches detected additional contaminants such as PAHs and phthalates in 128 real samples.
• Positive hits were confirmed and quantified by GC-MS/MS, showing strong agreement between platforms.

Benefits and Practical Applications

This integrated approach offers:

• High confidence in compound identification through accurate mass and retention time locking.
• Flexible adaptation to regulated residue methods or comprehensive contaminant screening.
• Improved laboratory throughput with a unified sample preparation for both targeted and untargeted analyses.

Future Trends and Opportunities

Emerging directions include:

• Expanding in-house accurate-mass libraries for broader analyte coverage.
• Automation of data processing workflows to handle larger sample batches.
• Combining GC-Q/TOF screening with machine learning for predictive contaminant profiling.

Conclusion

A dual-platform GC-MS strategy effectively addresses both targeted quantitation and untargeted contaminant profiling in fruits and vegetables. The retention-time locked, backflush method ensures reproducible separations and high-resolution mass measurements, delivering robust results that meet regulatory and research needs.

References

1. Chen K, Stevens J, Nieto S. GC/Q-TOF screening of pesticides in food. Agilent Technologies Application Note 5991-6884EN (2016).