Multi-Residue Method for Determination of 350 Pesticides in Food Extracts by utilizing new GC-MS/MS technology

Significance of the Topic

Reliable multi‐residue pesticide analysis in foodstuffs is critical for ensuring public health and meeting stringent regulatory standards. Complex food matrices such as herbs, spices and baby foods pose significant analytical challenges due to co-extracted interferences. High selectivity and sensitivity in detection are therefore essential to compensate for limited sample cleanup and to achieve unambiguous confirmation of trace-level residues.

Objectives and Study Overview

The study aimed to develop and validate a comprehensive GC-MS/MS method capable of quantifying 350 pesticide compounds in fruit and vegetable extracts. Key goals included:

• Implementing a generic QuEChERS-based sample preparation workflow with minimal cleanup.
• Enhancing detection selectivity and sensitivity using triple quadrupole MRM technology.
• Ensuring robust retention time reproducibility through Retention Time Locking (RTL).
• Demonstrating method linearity, limits of detection and ease of transfer across instruments.

Methodology and Instrumentation

Sample preparation employed a generic QuEChERS extraction of blank food matrices, spiked at levels of 1–200 ppb. Matrix-matched calibration standards were prepared in peppermint extract. Chromatographic separation was performed on an Agilent 7890A GC equipped with an HP-5MS Ultra Inert capillary column (30 m × 0.25 mm × 0.25 µm), using a PTV inlet in cold splitless mode and helium as carrier gas. An Agilent 7000A Triple Quadrupole MS system operated in MRM mode monitored two transitions per analyte (quantifier and qualifier). Retention time alignment was achieved via RTL locked to chlorpyrifos-methyl (16.59 min).

Main Results and Discussion

• Total Ion Chromatograms (TICs) and extracted MRM traces demonstrated clear separation and peak shapes for all target compounds at 200 pg on-column.
• Overlaid qualifier and quantifier ions confirmed identity for each analyte, even in complex peppermint extract.
• Calibration curves across seven levels (1–200 ppb) yielded correlation coefficients > 0.99 for all 350 pesticides.
• Limits of detection, calculated at S/N > 3, were below 2 pg on-column for most compounds, attesting to the high sensitivity.

Benefits and Practical Applications

• Exceptional selectivity and sensitivity enable reliable screening and confirmation of a broad pesticide panel in challenging matrices.
• Generic sample cleanup reduces method complexity and cost, while retaining performance.
• RTL facilitates rapid method transfer and reproducibility across multiple Agilent 7000A systems.
• Compliance with EU regulatory performance criteria supports application in food safety testing laboratories.

Future Trends and Opportunities

Advances in GC-MS/MS and data processing will continue to expand multi-residue capabilities. Potential developments include:

• Integration with high-resolution mass spectrometry for non-target screening.
• Automation of sample preparation and data review to increase throughput.
• Expansion of compound libraries to emerging and transformation products.
• Implementation of digital workflows and cloud-based analytics for decentralized testing.

Conclusion

The presented method employing Agilent 7000A GC-MS/MS with RTL and QuEChERS sample preparation delivers robust quantitative performance for 350 pesticides in complex food extracts. High sensitivity, selectivity and ease of transfer make it a powerful tool for routine pesticide monitoring in compliance with regulatory standards.