INVESTIGATION OF HEAVY METALS CONTENT IN SELECTED TEA BRANDS MARKETED IN PODGORICA, MONTENEGRO

Medicinal plants are sources of different chemical substances with different biological activities in living organism. Some of the chemical compounds so-called “heavy metals”, can be dangerous because they tend to bioaccumulate and transported in all biota via the food chain. The aim of our study was to investigate the concentration of heavy metals in commercially available tea samples purchased in markets in Podgorica, Montenegro state. The samples preparation has been performed using microwave digestion. The content of metals concentrations was determined by ICP-OES, while the mercury content is determined by DMA 80 and Perkin-Elmer Analyst 300. Results obtained in the present study showed that analysed samples of the investigated medicinal plants contain heavy metals namely copper, cobalt, chromium, iron, manganese, nickel, and zinc that are considered essential elements; and arsenic, cadmium, lead and mercury which are classified as highly toxic metals. The concentration (mg kg^-1) of heavy metals in all the tea samples was found to be as follows: arsenic (0.0107 to 0.2495), cadmium (0.001 to 0.01), copper (9.18 to 38.44), cobalt (0.005 to 0.032), chromium (0.007 to 0.089), iron (69.36 to 741.55), manganese (20.08 to 1521.15), mercury (0.0035 to 0.0177), nickel (1.32 to 10.68), lead (0.22 to 2.24) and zinc (16.44 to 30.04). Significant variation exists in the concentration of heavy metals in tea samples. Overall, the results of this study give current insights into the metal levels in analysed samples of teas which are commonly consumed in Podgorica. The variations in metals concentrations of the commercially available samples were attributed to several factors.