Fast analysis of multi-class Pesticides panel in wine and olive oil extracts using Single Run LC-Triple Quadrupole Mass Spectrometry

Importance of the Topic

Modern food safety laboratories face increasing demands for sensitive, broad-spectrum pesticide residue analysis to comply with stringent regulations and growing trade requirements. Rapid, reliable methods that cover hundreds of compounds in complex matrices such as wine and olive oil are essential to ensure consumer protection and regulatory compliance.

Objectives and Study Overview

This study presents a complete workflow, from sample preparation to data report, for multi-class pesticide analysis in wine and olive oil. The goals were to develop robust, high-throughput LC-MS/MS methods that meet EU SANTE validation criteria, enabling both quantitative determinations (over 250 analytes) and broad screening (over 550 analytes) in a single run.

Methodology and Instrumentation

Sample Preparation:

• Modified QuEChERS extraction without dispersive SPE cleanup.
• One microliter injection of pure acetonitrile extract for analysis.

Used Instrumentation:

• UHPLC: Thermo Scientific Vanquish Flex binary pump.
• Column: Accucore aQ, 100 × 2.1 mm, 2.6 µm, 25 °C.
• Mobile phases: Water + 5 mM ammonium formate/0.1% formic acid (A) and MeOH + 5 mM ammonium formate/0.1% formic acid (B).
• MS: Thermo Scientific TSQ Quantis triple quadrupole with ESI, polarity switching (–2,500 V; +3,500 V).
• Source gases and temperatures: sheath gas 30, aux gas 6, sweep gas 1, vaporizer 350 °C, transfer tube 290 °C.

Main Results and Discussion

Calibration and Linearity:

• Individual standards for 720 pesticides optimized by automated SRM infusion.
• Over 95% of 550 screened compounds achieved r2 > 0.990 over 0.5–100 ppb.

Limits and Recoveries:

• LODs and LOQs determined per EU guidelines; white wine LODs down to 0.5 ppb.
• Matrix-matched standards and extracted spikes yielded recoveries within acceptable ranges.

Method Robustness:

• Consistent retention times and peak shapes across ~1,000 injections.
• Stable column lifetime and reproducible ion ratios for confirmation transitions.

Benefits and Practical Applications

The developed methods allow routine food testing laboratories to:

1. Screen large pesticide panels quickly in a single LC-MS/MS run.
2. Minimize sample prep time and solvent use with simplified QuEChERS.
3. Meet EU MRL requirements with confident quantitation and confirmation.

Future Trends and Potential Applications

Potential extensions include:

• Expanding the compound database to emerging contaminants.
• Adapting protocols for additional complex matrices (e.g., juices, oils).
• Integrating advanced data-handling platforms for automated reporting and trend analysis.

Conclusion

A single-run LC-MS/MS workflow combining QuEChERS extraction and triple quadrupole detection offers a fast, sensitive, and robust solution for multi-class pesticide residue analysis in wine and olive oil, fully aligned with EU regulatory demands.

References

1. EUROPEAN COMMISSION – SANTE/11813/2017, November 2017