Complete Pesticides Workflow - Combination of LC-MS/MS and LC-HRAM Analysis

Significance of the topic

The routine surveillance of pesticide residues in food is critical to ensure consumer safety and to comply with stringent regulatory standards. Advanced analytical workflows that combine high sensitivity, accuracy, and broad compound coverage directly support quality assurance/control laboratories, regulatory agencies, and research groups in guaranteeing food integrity.

Objectives and Study Overview

This study presents a complete solution for pesticide residue analysis by comparing two mass spectrometry–based approaches:

• Liquid chromatography coupled to triple quadrupole mass spectrometry (LC-MS/MS)
• Liquid chromatography coupled to high-resolution accurate mass spectrometry (LC-HRAM)

The goal was to validate both methods against the European SANCO 12495/201 guidelines and to evaluate their performance across key food matrices: strawberry, leek, wheat flour, tea, and honey.

Methodology and Instrumentation

Both workflows used an UltiMate 3000 RSLC system with an Accucore aQ column (100×2.1 mm, 2.6 µm). Mobile phases were water/methanol (98:2) and methanol/water (98:2), each containing 5 mM ammonium formate and 0.1% formic acid. The injection volume was 1 µL, flow rate 300 µL/min, column temperature 25 °C, and total runtime 15 min.

• Triple Quadrupole MS: Thermo Scientific TSQ Endura, HESI source, targeted SRM with 1,045 transitions.
• HRAM MS: Thermo Scientific Q-Exactive Focus, HESI source, full-scan variable data-independent acquisition (vDIA).

Sample preparation employed QuEChERS extraction kits with matrix-matched calibration.

Main Findings and Discussion

Limits of quantitation (LOQs) for all 12 representative pesticides were below or at the regulatory maximum residue limits (MRLs) in every matrix. Key observations included:

• Triple quadrupole LOQs ranged from 0.005 to 1.0 µg/kg in solvent and maintained compliance across matrices.
• HRAM LOQs demonstrated enhanced sensitivity in complex matrices such as tea and honey, achieving <1 µg/kg for several analytes.
• Recovery studies at 10 µg/kg fortification showed 70–120% recoveries with repeatability (RSD) below 15% for both platforms.

Overall, both instruments met criteria for linearity, specificity, precision, and accuracy under SANCO guidelines.

Benefits and Practical Applications

The dual-platform strategy offers a flexible workflow:

• LC-MS/MS provides robust, high-throughput quantitation for routine monitoring.
• LC-HRAM enables retrospective data analysis and screening for non-target or suspect compounds.
• Unified sample preparation and runtime simplify method transfer across laboratories.

This integrated approach supports regulatory testing, food safety investigations, and research into emerging contaminants.

Future Trends and Potential Applications

Emerging developments likely to enhance pesticide residue analysis include:

• Advanced algorithms and AI-driven spectral deconvolution for complex matrix screening.
• Expansion of compound libraries and suspect screening databases in HRAM workflows.
• Miniaturized and green LC systems to reduce solvent use and environmental impact.
• Cloud-based data management to facilitate multi-lab harmonization and real-time reporting.

Conclusion

Both LC-MS/MS and LC-HRAM workflows demonstrated reliable, regulatory-compliant performance for pesticide residue analysis in diverse food matrices. Their complementary strengths—quantitative robustness and high-resolution screening—provide an effective, transferable solution for laboratories seeking comprehensive pesticide monitoring capabilities.

References

• European SANCO guidelines 12495/201