Determination of trace elements in zhaoping green tea by atomic absorption spectrometry with microwave digestion

The aanalysis of trace elements in tea is one of the important projects in tea research because of their great impact on the quality of tea.A method to determine trace elements of Cu,Fe and Zn in three kinds of green tea from Zhaoping was proposed.It used microwave assisted digestion with the mixtures of HNO3 and H2O2,and atomic absorption spectrometry detection.When temperature-programmed is used in digestion,higher recovery rates were achieved.The results of three kinds of green tea were comparatively analyzed.The recovery rates of determined elements were from 93.6% to 101.5%.The relative standard deviations for determination of these elements ranged from 0.58% to 3.16%;the content of each trace element in samples is Fe:98.95177.8μg/g,Zn:45.6759.29μg/g,Cu:19.7724.22μg/g.This method can provide a reliable,sensitive,selective,simple and environmental friendly approach in determine trace elements in tea and is suitable for routine analysis.