Easy and rapid method for the quantitative determination of pyrrolizidine alkaloids in honey by ultra performance liquid chromatography-mass spectrometry: An evaluation in commercial honey

Pyrrolizidine alkaloids (PAs) are toxins biosynthesised by plants and they are known to be present in approximately 6000 plant species, about 3% of all flowering plants. PAs are probably the most widely distributed natural toxins and represent a potential risk to human health, since poisoning caused by these toxins is associated with acute and chronic liver damage and may lead to death. One of the most common sources of PAs exposure in humans is honey consumption. We have developed a quick and easy method to quantify nine different PAs (echimidine, heliotrine, intermedine, lycopsamine, lasiocarpine, retrorsine, seneciphylline, senecionine, senkirkine) in honey based on QuEChERS sample extraction and ultra fast liquid chromatography coupled with mass spectrometry detection. We performed a validation study of the method and it resulted in good precision and accuracy, high recoveries, and good linear calibrations. The limit of detection ranged from 0.021 to 1.39 μg Kg−1 and the limit of quantification from 0.081 to 4.35 μg Kg−1. This new approach was applied to the quantification of PAs in retail honeys purchased in local supermarkets, classified by their country of origin: Italian honeys, blends of honey of European countries and blends of honey of European and non-European countries. The concentrations detected ranged from 1 to 169 μg PAs/kg−1 with higher concentrations in blends of European and non-European honeys. This study reveals that many samples tested would exceed the tolerable daily intake suggested for these substances and they could be a hazard to human health.