Investigation of heavy metal ion content in imported green tea using inductively-coupled plasma-optical emission spectroscopy (ICP-OES)

CHED 328

John F. Curran and Dr. Yuan Mei-Ratliff. Department of Chemistry, Western Connecticut State University, 181 White Street, Danbury, CT 06810
Green tea has become a popular everyday beverage in the US in recent years due to its many believed health benefits that are currently under investigation worldwide. Since most green tea products on the US market are imported from developing countries, there have been concerns over possible contamination including heavy metal ions that might be present in the soil in which the tea plants grew or introduced during the processing of tea products. Using ICP-OES as an analytical tool, studies have been carried out to analyze the lead and cadmium content, both in the tea leaves as well as the tea fusion, for over a dozen commercial green tea samples. Results from these analyses shed light on (1) the leaching patterns of heavy metal elements from tea leaves into their brew and (2) the varying abilities of tea leaves to retain minerals from their environment of growth.