Quantitation of Neonicotinoid Pesticides in Honey with the Agilent 1290 Infinity II LC and Agilent 6470 Triple Quadrupole LC/MS

Importance of the topic

Neonicotinoid insecticides are widely used in agriculture but may contaminate honey at trace levels, posing risks to pollinator health and food safety. Robust analytical methods capable of detecting these residues at sub-µg/kg levels are crucial for regulatory compliance and environmental monitoring.

Objectives and Study Overview

This study presents a streamlined LC–MS/MS approach for quantifying eight neonicotinoids in commercial honey samples using an Agilent 1290 Infinity II liquid chromatograph coupled to an Agilent 6470 triple quadrupole mass spectrometer. Samples were spiked at 5 and 20 µg/kg to assess method performance in terms of recovery, repeatability, and matrix effects over extended sequences.

Methodology and Instrumental Setup

Sample preparation consisted of simple dilution and the addition of isotopically labeled internal standards without cleanup steps. Separation was achieved on an Agilent InfinityLab Poroshell 120 SB-C18 column (2.1×100 mm, 2.7 µm) at 40 °C with a gradient elution of ammonium formate/formic acid in water and 0.1% formic acid in acetonitrile. The flow rate was 0.3 mL/min and injection volume 20 µL. Detection employed electrospray ionization in positive mode with scheduled multiple reaction monitoring transitions optimized for each analyte.

Main Results and Discussion

The method showed excellent retention time precision (%RSD < 0.5%) and signal stability over a 52-hour sequence involving 90 injections of spiked honey and reference solutions. Uncorrected peak area variability ranged from 3.7% to 13.2%, improving to below 5% for most analytes after correction with labeled internal standards. Limits of quantitation ranged from 0.5 to 2 µg/kg, aligning with EU maximum residue levels. Recoveries after isotope dilution correction were 95–112%, while uncorrected recoveries varied between 70% and 130%, highlighting the importance of internal standard calibration.

Practical Benefits and Applications

The described workflow enables high-throughput, sensitive quantification of neonicotinoids in honey without extensive sample cleanup, reducing analysis time and matrix interferences. It is well suited for routine monitoring laboratories to ensure compliance with MRLs and support research into pesticide exposure in apiculture.

Future Trends and Potential Applications

Future developments may include coupling targeted LC–MS/MS methods with high-resolution mass spectrometry for non-target screening, miniaturized sample preparation for on-site testing, and automated platforms for large-scale surveillance of bee products.

Conclusion

The combination of the Agilent 1290 Infinity II LC and 6470 triple quadrupole MS provides a robust, sensitive, and efficient solution for monitoring neonicotinoid residues in honey. The method maintains performance over prolonged sequences, supports regulatory compliance, and contributes to environmental and food safety efforts.

References

1. Raina‐Fulton R, Behdarvandan A. Liquid Chromatography‐Mass Spectrometry for the Determination of Neonicotinoid Insecticides and their Metabolites in Biological, Environmental and Food Commodity Matrices. Trends in Chromatography. 2016;10:51–79.
2. Proietto Galeano M, et al. UHPLC/MS-MS Analysis of Six Neonicotinoids in Honey by Modified QuEChERS: Method Development, Validation, and Uncertainty Measurement. Int J Food Sci. 2013;1–7.
3. Neonicotinoids: The Science and Regulatory Complexity. Covance ebook EBKCPC005. 2019.
4. Annex 1 to Regulation (EC) No. 369/2005 of the European Parliament and of the Council on Maximum Residue Levels of Pesticides in or on Food and Feed. 2005.