Polarographic determination of selenium in tea leaves using a dropping mercury electrode

A new polarographic method is described for the estimation of selenium in tea leaves. Copper with selenium can produce intermetallic Cu-Se compound in acetic acid-EDTA solution. The intermetallic Cu-Se compound yields a well-defined high sensitivity polarographic wave at a potential of about −0.7 V (vs SCE). Under optimum conditions, the wave height is proportional to the concentration of selenium (IV) in the range of 0.04–0.4 μg/ml. The method has been used to determine selenium in tea leaves and results obtained agreed favourably with an atomic absorption method.