Determination of trace elements and heavy metals content of green and black tea varieties consumed in Iran

Abstract

The aim of the present study was to determine the level of selected heavy metals in green and black tea varieties consumed in Iran. Samples were prepared with the acid digestion method and measured by polarography. The mean concentration of Zn, Cd, Pb and Cu was 0.505±1.632, 0.417±0.268, 0.325±0.249 and 4.151±3.739 mg/100 g for black tea, and 2.442±4.003, 0.284±0.198, 0.395±0.279 and 5.723±4.286 mg/100 g for green tea, respectively. Results showed no statistically significant difference among the samples with various flavors. Green tea samples were accompanied with high concentration of Zn, Pb and Cu and lower concentration of Cd in comparison with black tea samples. The mean concentration of Cu and Cd had no significant difference in the level of the reference article. Although the level of heavy metals in samples varied from non-detectable doses to extremely high concentration, the mean concentration of each element was in an acceptable range.