Determination of heavy metals concentration in commercial green tea samples by using inductively coupled plasma optical emission spectrometer (ICP-OES)

Abstract

Tea is one of the most consumed beverages across the world as it refreshes their psychic health rejuvenating them from stress. The aim of the present work is to determine the heavy metals and physicochemical parameters present in green tea (GT) made from major brands available in the local Indian market, more specifically heavy metals Arsenic (As), Cadmium (Cd), Chromium (Cr), Lead (Pb), Selenium (Se) and Zinc (Zn). A total of four samples were investigated with the Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). Arsenic concentration was not detected in any one of the samples. Cr concentration was found to be the same in all the samples at a very low concentration of 0.001mg kg-1, Cd concentration varies from 0.04 to 0.07 mg kg-1, Pb concentration varies from 0.03 to 0.08 mg kg-1, Se concentration varies from 0.068 to 0.098 mg kg-1 and Zn concentration varies from 9.45 to 18.16 mg kg-1 respectively and their concentration levels are below the permissible limits of WHO. The concentrations of present anion groups like SO42-, S2-, NO3-, NO2-, PO43- and NH3 in the selected samples were high and might affect the health of the consumers of green tea.