Exploring the application of a universal method for pesticide screening in foods using a high data acquisition speed MS/MS

Significance of the Topic

The monitoring of pesticide residues in food is critical for public health and environmental protection. A rapid, universal screening approach reduces analytical complexity, accelerates decision making, and supports regulatory compliance across diverse commodities.

Study Objectives and Overview

This work evaluates a generic, high-throughput multiple reaction monitoring (MRM) method for the simultaneous screening of 172 pesticides in various food matrices. The goal is to demonstrate that ultra-fast data acquisition MS/MS can reliably identify trace levels of agrochemicals without compound-specific method development.

Methodology and Instrumentation

The sample preparation follows a modified QuEChERS protocol:

• 5 g of homogenized sample hydrated with water
• Extraction with 50 mL acetonitrile and salting-out with NaCl and phosphate buffer
• Cleanup using ENVI-Carb/LC-NH₂ SPE
• Concentration and reconstitution in methanol for LC/MS analysis

The analytical platform comprises:

• UHPLC: Nexera system equipped with Shim-pack XR-ODSII column (75 × 2 mm, 2.2 µm)
• Mobile phases: 5 mM ammonium acetate in water and methanol, gradient 30–95 % B over 15 min
• MS/MS: Shimadzu LCMS-8040 triple quadrupole with ESI (±), 350 °C desolvation
• MRM: 344 transitions (two per compound), 5 ms dwell time, 1 ms pause, positive/negative polarity switching in 15 ms

Key Results and Discussion

Ten pesticides spiked at 10 ppb in leek, paprika, and green tea were automatically detected without retention time scheduling. MRM chromatograms showed clear baseline separation and consistent signal intensity. False positive rates ranged from 7 to 10 across matrices, reflecting the challenges of complex backgrounds but demonstrating robust automatic peak selection.

Benefits and Practical Applications

• Eliminates the need for individualized MRM scheduling, simplifying method setup
• Supports high sample throughput with full-run acquisition (0–20 min) and rapid MRM cycling
• Offers reliable detection at regulatory-relevant levels (≤10 ppb)
• Applicable across diverse food types without revalidation for each analyte

Future Trends and Opportunities

Integrating high-resolution full-scan workflows could complement universal MRM for non-target screening. Advances in data processing and machine learning may further reduce false positives. Expansion of compound libraries and green extraction protocols will enhance sustainability and broaden applicability.

Conclusion

The universal high-speed MRM method on the LCMS-8040 platform provides a rapid, flexible solution for multi-pesticide screening in foods. It achieves automated detection at low ppb levels across various matrices without compound-specific optimization, streamlining routine monitoring workflows.