Zinc, copper, lead and cadmium contents in green tea

The levels of zinc, copper, lead and cadmium in green tea have been determined by atomic absorption spectrophotometry. With the growth and development of tea shoots, zinc, copper, lead and cadmium concentrations decreased gradually. Some of the lead in green tea was eliminated by washing with water before manufacturing. The range and mean of the zinc, copper, lead and cadmium in 139 green teas were as follows: zinc, 23.4–100.5 and 54.4 μg/g; copper, 4.7–36.5 and 11.4 μ/g; lead, 0.11–1.93 and 0.49 μg; cadmium, 0.013–0.098 and 0.036 μg/g. Significant differences in the contents of copper and lead were observed among the different districts of the country. The green tea produced in some districts near the metropolis areas contained the highest concentration of lead.