Abstract:

Totally 150 Pu er tea samples from 5 main producing areas (including 6 representative brands with 5 replicates each brand comprising 3 raw Pu er tea and 3 ripe Pu er tea each area) in Yunnan province were tested for the contents of As and Hg by the atomic fluorescence spectrometric (AFS) methods recommended by the Chinese national standards GB/T 5009.11 －2003 and GB/T 5009.17－2003. Results showed that the content ranges of As and Hg in the Pu er tea samples were 0.026－0.37 mg/kg md and 0.0014－0.020 mg/kg md, respectively. No Hg was detected in 85.9% of the total number of samples. The determination results demonstrate that these samples are all in accordance with the quality standard requirements of the Chinese Ministry of Agriculture for Pu er tea. There were differences in the contents of As and Hg among Pu er tea samples from 5 main producing areas in Yunnan province. Differences in the contents of As and Hg were observed between raw Pu er tea and ripe Pu er tea, whereas they both exhibited good quality safety. In conclusion, the quality safety status of all these samples is good in terms of the contents of As and Hg.

Key words: Pu er tea, arsenic, mercury, safety status