SCIENCE ALERT: Pyrrolizidine alkaloids: an optimized green method of analysis for aromatic herbs (Food Chemistry)

Editor's Note

Pyrrolizidine alkaloids (PAs) are secondary plant metabolites that have been found in more than 6000 species globally including in common widespread plant families such as Asteraceae, Boraginaceae, and Fabaceae. Some PAs have been reported to be hepatotoxic to humans and livestock, and European authorities proposed maximum limits for PAs in a variety of foodstuffs, ranging from 150-400 ug/kg for most herbal products. Researchers here report an optimized validated method for PA analysis using a novel environmentally friendly microextraction method paired with ultra-high performance liquid chromatography coupled to tandem mass spectrometry detection for efficient and accurate determination of 21 PAs. The method was applied to 17 aromatic herbs in commerce including thyme, rosemary, and basil. All 17 samples showed presence of PAs with lasiocarpine, europine N-oxide, and senecivernine N-oxide as the main PAs detected in samples, with an average concentration of 262 ug/kg.

June 2022

Food Chemistry

DOI: https://doi.org/10.1016/j.foodchem.2022.132189

Miniaturized and modified QuEChERS method with mesostructured silica as clean-up sorbent for pyrrolizidine alkaloids determination in aromatic herbs

Abstract

This work proposes the miniaturization and modification of the QuEChERS strategy using different large pore mesostructured silicas, non-modified and modified with amino groups (NH2), as dispersive clean-up sorbents for multi-component extraction of 21 pyrrolizidine alkaloids from different aromatic herbs, combined with ultra-high performance liquid chromatography coupled to tandem mass spectrometry analysis. The procedure was miniaturized by reducing the amounts of sample (0.2 g), solvents (2 mL), clean-up sorbents (25 mg sorbent + 150 mg MgSO4) and partitioning salts (0.65 g) employed. Best results were achieved using mesostructured silicas (LP-MS-NH2) than conventional PSA. The method was validated (overall recoveries 73–105%) and applied to the analysis of 17 samples. All the samples were contaminated with PAs (average concentration 262 µg/Kg). Thyme and basil samples were the most contaminated, whereas rosemary was the least. Lasiocarpine, senecivernine N-oxide and europine N-oxide were the main PAs that contributed to their contamination.