Determination of Fifteen Rare Earth Elements in Green Tea Leaves and Their Tea Infusions Consumed in Zhejiang Province, China

Using the inductively coupled plasma mass spectrometer (ICP-MS) determined the contents of 15 rare earth elements in 28 green tea samples and 6 tea infusions which collected in Zhejiang province, China. La, Ce, Nd and Y are the dominants elements amongst 15 rare earth elements, the maximum of rare earth elements in the 28 green tea samples is 2.0 mu g g(-1), the content of Ce. Total rare earth elements oxide of 28 samples range from 0.4 to 7.3 mu g g(-1), the total rare earth elements oxides of 6 samples exceed the national standard of maximum levels. Otherwise the rare earth elements in the infusion of those 6 green tea samples are far more below the permission concentration in drinking water. The extraction efficiency of rare earth elements into the infusion is 3.4 % in average. The contradiction between the standards of green tea leaves and their infusion concentrations can be contribute to the low extraction efficiency of rare earth elements in the green tea samples into their infusions.