Development of a high-resolution MRM quantitative method for pesticides in apple, honey, olive oil, orange and tomato food matrices

Importance of the Topic

The reliable quantitation of trace pesticide residues in diverse food matrices is essential to protect consumer safety and comply with regulatory standards. High-resolution mass spectrometry techniques offer enhanced sensitivity and selectivity for multi-residue analysis, enabling detection at or below established maximum residue levels.

Objectives and Overview of the Study

This work aimed to develop and validate a high-resolution multiple reaction monitoring (MRM) method using an LC-QTOF instrument for quantifying over 300 pesticide residues in apple, honey, olive oil, orange, and tomato matrices. The method was benchmarked against a data-independent acquisition (DIA-MS/MS) approach to assess improvements in detection limits and selectivity.

Materials, Methods, and Instrumentation

• Sample preparation: 317 pesticides and 10 deuterated internal standards spiked into five food commodities at 0.1–100 µg/kg, extracted via QuEChERS.
• Chromatography: reverse-phase separation on Shim-pack Velox Biphenyl column (100×2.1 mm, 2.7 µm) at 45 °C.
• Mass spectrometry: Shimadzu LCMS-9050 QTOF in positive ESI mode with external calibration, full MS scan (m/z 110–950) and targeted MRM transitions using optimized collision energies from a triple quadrupole database.

Used Instrumentation

• Shimadzu LCMS-9050 high-resolution QTOF mass spectrometer
• Shim-pack Velox Biphenyl column with guard
• Standard QuEChERS extraction tools

Main Results and Discussion

• High-resolution MRM mode produced up to twofold higher fragment ion intensities compared to DIA-MS/MS, achieving quantitation limits below 1 µg/kg for many targets.
• System repeatability (%RSD ≤20%) was demonstrated for 312 pesticides at 10 µg/kg in tomato matrix (n=6).
• Tailored collision energies and narrow mass windows (±30 mDa) enhanced reference ion signal-to-noise and selectivity.
• In complex matrices like olive oil, MRM improved both sensitivity and selectivity over DIA with wide precursor isolation windows.

Benefits and Practical Applications

• Compliant with EU SANTE 11312/2021 guidelines for multi-residue pesticide analysis at the default MRL of 10 µg/kg.
• Enables laboratories to achieve lower limits of quantitation and robust trace-level detection.
• Applicable to routine food safety QA/QC and regulatory compliance across varied commodity types.

Future Trends and Applications

Incorporating high-resolution MRM workflows can extend to other contaminants such as veterinary drugs and mycotoxins. Advances in ion mobility separation and hybrid acquisition strategies may further enhance throughput and analytical specificity.

Conclusion

The developed high-resolution MRM method on a QTOF platform demonstrated superior sensitivity and selectivity over DIA-MS/MS for over 300 pesticides across multiple food matrices. This approach satisfies regulatory requirements and supports reliable low-level residue quantitation for food safety analysis.