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Zinc, copper, lead and cadmium contents in green tea
Author(s) -
Tsushida Tojiro,
Takeo Tadakazu
Publication year - 1977
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740280306
Subject(s) - cadmium , copper , zinc , chemistry , atomic absorption spectroscopy , lead (geology) , green tea , environmental chemistry , food science , biology , paleontology , physics , organic chemistry , quantum mechanics
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.