Study Reveals Low Transfer of Pesticide Residues from Herbs to Infusions

In a recent study published in the Journal of Separation Science, researchers have validated a gas chromatography-mass spectrometry method for the analysis of pesticide residues in herbs and their subsequent transfer to infusions (1). Lead author Sara C. Cunha and her team employed a quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure for analyzing pesticide residues in herbs, as well as a dispersive liquid-liquid microextraction method for analyzing infusions.

Wooden crate with variety of potted culinary herbs | Image Credit: © exclusive-design - stock.adobe.com

The method demonstrated excellent performance, aligning well with existing guidelines for pesticide residue analysis. Out of the 58 herb samples examined, belonging to 20 different species, an alarming 80% contained detectable levels of at least one pesticide. Furthermore, 62% of these samples exceeded the maximum residual level allowed.

Interestingly, the study found that naturally contaminated herbs did not transfer pesticide residues significantly to the herbal infusions. To confirm this, the researchers conducted a control experiment by artificially spiking a blank herb sample with a high concentration of each pesticide (7 mg/L). Surprisingly, only 15 analyzed pesticides were detected in the infusion, and their levels were below the limit of quantification.

These findings provide valuable insights into the safety of herbal infusions and address concerns regarding pesticide residues. The validated gas chromatography-mass spectrometry method presented in this study offers a cost-effective approach for the analysis of pesticide residues in herbs. With its good accordance with current guidelines, this method holds promise for future quality control and safety assessments of herbal products.

Further studies are warranted to explore additional factors that may affect the transfer of pesticide residues and to expand the analysis to a wider range of herbs and infusions. Nonetheless, this study provides a significant step forward in understanding the dynamics of pesticide residues in herbal products, paving the way for safer and more reliable herb consumption.

Reference

(1) Caldeirão, L.; Godoy, H. T.; Fernandes, J.; Cunha, S. C. Pesticide residues in herbs and their transfer for infusions. J. Sep. Sci. 2023. DOI: https://doi.org/10.1002/jssc.202300069