Pesticide residues in herbs and their transfer for infusions.

In this work, a cost-effective gas chromatography-mass spectrometry method was validated for the analysis of twenty-five pesticide residues in herbs and infusions using a quick, easy, cheap, effective, rugged, and safe procedure or a dispersive liquid-liquid microextraction method, respectively. Figures of merit of the method showed good accordance with current guidelines. From the 58 herb samples studied (pertaining to 20 different species), 80% presented at least one detectable pesticide, with 62% of them above the maximum residual level. Results showed that pesticide residues from naturally contaminated herbs were not transferred at a significant rate to the herbal infusions. When a control assay was conducted by spiking a blank herb sample with a large amount of each pesticide (7 mg/L) 15 analytes were detected below the limit of quantification in the infusion.