Multimycotoxin UPLC−MS/MS for Tea, Herbal Infusions and the Derived Drinkable Products

In recent years the consumption of tea and herbal infusions has increased. These hot drinks are consumed as daily drinks as well as for medicinal purposes. All tea varieties (white, yellow, green, oolong, black and puerh) originate from the leaves of the tea plant, Camellia sinensis. All extracts made of plant or herbal materials which do not contain Camellia sinensis are referred as herbal infusions or tisanes. During processing and manufacturing fungal contamination of the plant materials is possible, enabling contamination of these products with mycotoxins. In this study a multimycotoxin UPLC−MS/MS method was developed and validated for the analysis of the raw tea and herbal infusion materials as well as for their drinkable products. The samples were analyzed by ultra-high-performance liquid chromatography−tandem mass spectrometry (UPLC−MS/MS), with a mobile phase consisting of variable mixtures of water and methanol with 0.3% formic acid. The limits of detection for the different mycotoxins varied between 2.1 μg/kg and 121 μg/kg for raw materials and between 0.4 μg/L and 46 μg/L for drinkable products. Afterward 91 different tea and herbal infusion samples were analyzed. Only in one sample, Ceylon melange, 76 μg/kg fumonisin B1 was detected. No mycotoxins were detected in the drinkable products.