Effectiveness of accelerated solvent extraction compared to QuEChERS methods for the multiresidue analysis of pesticides in organic honey by GC-MS/MS

Importance of the topic

Honey is a complex natural product valued for its nutritional and therapeutic properties but prone to pesticide contamination through environmental exposure and hive treatments. Monitoring multiresidue levels in organic honey is crucial to ensure food safety, comply with regulatory limits, and protect bee health while maintaining analytical efficiency and cost-effectiveness.

Objectives and Study Overview

This work compares two inline accelerated solvent extraction (ASE) cleanup strategies with a standard QuEChERS protocol for the simultaneous determination of 53 pesticides in organic honey using GC-MS/MS. The aim is to evaluate extraction efficiency, cleanup performance, method sensitivity, and repeatability against European SANTE validation criteria.

Methodology and Instrumentation

• Samples: 45 organic honey lots (10 German orange blossom; 15 Calabria, south Italy; 20 Trentino-Alto Adige, north Italy) stored at –20 °C prior to analysis.
• Extraction approaches:
  • ASE with acetonitrile and PSA sorbent in-line cleanup
  • ASE with n-hexane/ethyl acetate (4:1) and Florisil sorbent
  • Conventional QuEChERS with MgSO₄, salts and dSPE cleanup (PSA/C18)
• Instrumentation:
  • Thermo Scientific Dionex ASE 350 extractor
  • Rocket Evaporator for extract concentration
  • Thermo Scientific TRACE 1310 GC with TG-5SilMS column (30 m × 0.25 mm × 0.25 µm)
  • Thermo Scientific TSQ 8000 Triple Quadrupole GC-MS/MS in SRM mode
• Validation: SANTE/11945/2015 guidelines—selectivity, linearity, limits of detection (LOD/LOQ), recovery (70–120%), and precision (RSD ≤ 20%). Matrix-matched calibration with internal standard (3-fluoro-2,2,4,4,6-pentabromodiphenyl ether).

Main Results and Discussion

• Linearity: ASE with acetonitrile/PSA achieved r² > 0.99 and LOQ ~7 ng/g; QuEChERS gave r² ~0.95 and LOQ ~22 ng/g.
• Recoveries: Both QuEChERS and ASE–acetonitrile/PSA yielded 70–120% for most analytes at 10, 50, 100 ng/g fortification levels, whereas ASE with hexane/ethyl acetate/Florisil showed sub-70% recoveries for several pesticides.
• Precision: Repeatability (CV) was < 20% for over 90% of compounds with QuEChERS and ASE–acetonitrile/PSA.
• Matrix effects: Inline ASE cleanup minimized co-extracted sugars and waxes, reducing maintenance and improving quantification stability.
• Real samples: Boscalid and diazinon detected in all Italian samples (up to 10 ng/g); chlorpyrifos-methyl found at high levels in some German samples (up to 390 ng/g), reflecting regional pesticide use patterns.

Benefits and Practical Applications

Inline ASE with acetonitrile and PSA offers a single-step extraction and cleanup, lowering solvent consumption, shortening preparation time, and reducing instrument contamination. The approach meets stringent validation criteria for multiresidue pesticide screening and quantification in complex food matrices.

Future Trends and Potential Applications

Further development may include adapting inline ASE workflows to other food and environmental matrices, exploring greener solvents, integrating automatic fractionation, and coupling with high-resolution mass spectrometry for broader pesticide and contaminant profiling. High-throughput miniaturized systems could enhance routine monitoring in industrial and regulatory laboratories.

Conclusion

The ASE method employing acetonitrile and PSA inline cleanup outperformed QuEChERS and ASE with Florisil in terms of sensitivity, recovery, and precision for the analysis of 53 pesticide residues in organic honey by GC-MS/MS. This efficient, cost-effective workflow simplifies sample preparation and ensures compliance with food safety standards.

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