Elemental content in hemp-based herbal teas by ICP-MS

Cannabis sativa L. is one of the earliest and most widely cultivated herbaceous plants. It is known for its medicinal and healing properties, thanks to cannabinoids, but it has applications in various industrial and edible hemp products. Recently, it has found widespread use as a herbal tea, especially among young people (Fig. 1). However, contaminants, including toxic or potentially toxic metals, can accumulate in the cannabis plant and are a potential source of risk for human health and for the safety of marketed food products [1,2]. This study reports an analytical method to miniaturize the sample digestion for hemp-based herbal teas by inductively coupled plasma mass spectrometry (ICP-MS) in order to achieve accurate and reproducible results with low detection limits for the analyzed elements. The best sample preparation procedure was evaluated using different reagent mixtures and four food standard reference materials (NIST1515, NIST1547, INCT-TL-1 and BCR482). The use of a 3 mL reagent mixture consisting of HNO3 and H2O2, 2:1 (v/v) was found to produce satisfactory results in all cases. The optimized method was subsequently applied to real commercially available samples. The detected levels of the most toxic elements were below the prescribed limits established by the WHO. This method can be used for routine analysis and food quality control applications. Acknowledgements: This work was funded by the project 2021 RM12117A5D872C39 (Principal Investigator M.L. Astolfi) financed by Sapienza University of Rome. References [1] Zafeiraki E., Kasiotis K.M., Nisianakis P., Machera K. Frontiers in Chemistry, 2021, 9, 654308. [2] Placido D.F., Lee C.C. Plants, 2022, 11, 595.