Heavy Metals in some Commercial Herbal Teas

Nicoleta MUNTEAN, Edward MUNTEAN, Călina CRETA, Marcel DUDA

Abstract


As plant matrix from which herbal teas are prepared are subjected to environmental pollution, the focus of this study was directed towards the heavy metal content of some commercially available products: basil (Basilici Folium), chamomile (Chamomillae Folium), mulberry (Mori Folium), plantain (Plantaginis Folium), dandelion (Taraxaci Herba), mint (Menthae Herba), St. John's wort (Hyperici Herba), marigold (Calendula Flos), fennel (Foeniculi Fructus) and dill (Anethi Fructus). Heavy metals were determined using atomic absorption spectrophotometry, measurements being performed using a Shimadzu AA-6300 double beam atomic absorption spectrophotometer with graphite furnace, after microwave-assisted digestion. All analyses were made in triplicate and mean values were reported. The recorded concentrations for copper ranged from 2.34 mg/kg (dill) to 13.32 mg/kg (mint), with an average of 6.30 mg/kg; a close average concentration was recorded for Zn (6.34 mg/kg), with a range of values from 1.45 mg/ kg (fennel) to 20.09 mg/kg (mint). For cadmium, the concentration range was from 0.88 μg/ kg (plantain) to 20.22 μg/kg (mint), with an average of 6.65 μg/kg. Lead concentrations ranged from 0.07 μg/ kg (chamomile) to 45.01 μg/kg (dill), with an average of 15.39 μg/kg. The heavy metals contents of herbal teas are variable due to the factors like differences between the plants species, geographical area and exposure to different pollution sources, conditions of drying process.


Keywords


: heavy metals, herbal teas, atomic absorption spectrophotometry, GFAAS

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