Abstract: Taking the commercial black tea,green tea and slimming tea as the research object,six kinds of water samples from dormitory water,laboratory tap water and water from outside the school in Yuzhong Campus of Northwest University for Nationalities were selected.6 kinds of tea samples of different water samples of concentrated tea,light tea,tea leaf tea and tea in the detection of heavy metal elements Zn,Te,Sn,Cd and Pb content.Three kinds of tea samples were digested by wet method,and the other six kinds of water samples were sonicated respectively.The content of five heavy metal elements in each sample was determined by air-acetylene flame method (AAS) under the best working condition of the instrument.The results showed that both Te and Sn in black tea and green tea were detected,the content of toxic heavy metals Pb and Cd were lower than the standard limit of GB 2762-2017,and the content of Zn was higher.Te and Sn were not detected in slimming tea,and Pb and Cd The content of Zn was relatively high,and the content of Zn was also relatively high.The contents of heavy metals in concentrated tea and light tea brewed by 6 different water samples were different.The contents of Zn,Te,Sn,Cd and Pb were detected,and the content of Cd was slightly exceeded.No Te element was detected in the commercial packaging water 2 (pure water) and 3 (mineral water),and the other 4 trace elements All of the six water samples were detected by Pb (slight over standard),the other elements were within the normal range;the repeatability of the test and the precision of the instrument were good with the recoveries of 94.53% -108.56%.The contents of heavy metal elements in three kinds of tea tested in this research were different,and the contents of heavy metal elements in tea were related to water quality.Meanwhile,the quality of three kinds of commercial drinking water was good and the quality of three kinds of tap water was not equal.Drinking tap water was not recommended.

Key words: atomic absorption method, tap water, drinking water, tea, heavy metal element