Development, validation, and application of a multimatrix UHPLC-MS/MS method for quantification of Datura-type alkaloids in food

Abstract

A quantitative ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the determination of tropane alkaloids (TAs), atropine and scopolamine, in a variety of food products. The sample preparation of cereal-based food, oilseeds, honey, and pulses consisted of a solid–liquid extraction with an acidified mixture of methanol and water, while an additional step of solid-phase extraction on a cation-exchange sorbent was introduced in the treatment of teas and herbal infusions, aromatic herbs, spices and food supplements. The limits of quantification of the method varied from 0.5 to 2.5 µg kg−1. Apparent recovery was in the range of 70–120%, and repeatability and intermediate precision were below 20%. The method was successfully applied in a proficiency testing exercise as well as in the analysis of various commercial foods. Only 26% of the analysed food samples contained one or both TAs. The mean concentrations for atropine and scopolamine amounted to 21.9 and 6.5 µg kg−1, respectively, while the maximum concentrations were 523.3 and 131.4 µg kg−1, respectively. Overall, the highest levels of TA sum were found in an herbal infusion of fennel and a spice mix containing fennel and anise seeds.