Method for the determination of 431 Residual Pesticides in Honey using LCMS-8050 and GCMS-TQ8040 NX

Importance of the Topic

The presence of pesticide residues in honey poses significant health risks and is tightly regulated by the European Union. Analytical challenges arise from the complex, high-sugar matrix of honey, demanding sensitive and reliable multi-residue methods for routine monitoring.

Study Objectives and Overview

This work presents a validated protocol for the simultaneous determination of 431 pesticides in honey using two complementary techniques:

• LC-MS/MS for 244 compounds
• GC-MS/MS for 214 compounds
• 27 common analytes quantified by both methods

The method aims to achieve low limits of quantitation, high throughput and regulatory compliance for pesticide residue analysis in honey.

Methodology and Sample Preparation

Honey samples were homogenized and spiked to prepare matrix-matched calibration standards and recovery samples. A single liquid-liquid extraction using ethyl acetate and Na2SO4 was performed, followed by:

• GC-MS/MS cleanup: primary-secondary amine (PSA) and anhydrous MgSO4
• LC-MS/MS reconstitution: methanol:water (60:40, v/v)
• Filtration of both extracts through 0.22 µm nylon filters
• Calibration ranges: 0.2–20 µg/L (LC) and 1–50 µg/L (GC) with weighted (1/C2) external standards

Instrumentation Used

• Shimadzu LCMS-8050 with Nexera X2, Shim-pack XR-ODS column, ESI source
• Shimadzu GCMS-TQ8040 NX with AOC-20i+s, SH-Rxi-5Sil MS column, EI source
• LabSolutions Insight software and Shimadzu Method Packages/Smart Pesticides Databases for method optimization

Main Results and Discussion

Validation followed SANTE guidelines for specificity, linearity, recovery and precision:

• Specificity: blank signals < 30 % of reporting limits
• Linearity: correlation coefficients (R2) > 0.98; accuracy 80–120 % at all levels
• Recoveries at LOQ: 190 (LC) and 207 (GC) analytes between 70 and 120 %; all RSDR < 20 %
• Precision: RSDr and RSDR < 20 % across spiking levels
• LOQ achievements:
  
  • LC-MS/MS: 1 µg/kg for 123 compounds, 2 µg/kg for 18, 5 µg/kg for 80, 10 µg/kg for 21
  • GC-MS/MS: 1 µg/kg for 18 compounds, 5 µg/kg for 158, 10 µg/kg for 50

Benefits and Practical Applications

• Rapid, ultra-fast analysis with minimal sample prep
• High sensitivity suitable for trace-level pesticide monitoring
• Wide pesticide coverage aligning with EU MRL requirements
• Ease of implementation in QA/QC laboratories and research settings

Future Trends and Potential Applications

• Integration of high-resolution mass spectrometry for non-targeted screening
• Automation of sample preparation workflows to increase throughput
• Expansion of pesticide databases to include emerging and transformation products
• Adaptation of this approach to other challenging food matrices

Conclusion

The combined LC-MS/MS and GC-MS/MS method provides a robust, sensitive and reproducible platform for the comprehensive analysis of pesticide residues in honey, supporting regulatory compliance and consumer safety.

Reference

Guidance document on analytical quality control and method validation procedures for pesticide residues and analysis in food and feed. SANTE/11312/2021