DETERMINATION OF COPPER, NICKEL AND CHROMIUM CONTENTS IN CULTIVATED TEA IN NORTH OF IRAN

摘要

The aim of this study is to investigate the copper (Cu), nickel (Ni) and chromium (Cr) levels in cultivated black tea in north of Iran. The infusions of Cu, Cr and Ni in tea after 5, 15 and 60 min brewing time were measured. Results showed that the highest (2.32 +/- 2.63 mg/kg) and the lowest (2.16 +/- 1.84 mg/kg) mean levels of Cu were observed after 15 and 60 min, respectively. The mean levels of Ni and Cr at 60 min were the highest (13.72 +/- 8.09 mg/kg and 1.30 +/- 1.03 mg/kg, respectively) and at 5 min were the lowest (6.80 +/- 4.95 mg/kg and 0.88 +/- 0.79 mg/kg, respectively).