Determination of the inorganic constituents of commercial teas and their infusions by the technique of energy dispersive X-ray fluorescence spectrometry

摘要

With the global increase in use of herbal products, such as herbal teas, it has become necessary to obtain information about their inorganic constituents. In this context, the objective of this research was to determine the inorganic constituents of commercial teas (dry leaves) and their infusions in hot water by Energy Dispersive Fluorescence X-ray Spectrometry. In this study, fourteen different varieties of tea were selected from the most commonly encountered and consumed in Brazil. Energy Dispersive Fluorescence X-ray Spectrometer was able to identify in dry tea the elements potassium, sulfur, calcium, copper, phosphorus, iron, and manganese. In the infusions, only sulfur, calcium, and potassium were detected in low concentrations. Potassium has presented the highest concentration in the samples of commercial dry teas and while the infusions, sulfur has presented the highest migration and consequently, it was the most abundant element. Moreover, heavy metals were not found in any concentrations that would be considered harmful to human health.