Analysis of trace metals and perfluorinated compounds in 43 representative tea products from South China

Six trace metals (Cd, Pb, Cr, Cu, Zn, and Mn) and 2 perfluorinated compounds (PFCs), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), were analyzed in 43 representative tea products (including 18 green, 12 Oolong, and 13 black teas) from 7 main tea production provinces in China, using the atomic absorption spectrophotometer for trace metals analysis and HPLC-MS/MS for PFOS and PFOA analysis. The average contents of the 3 essential metals Mn, Cu, and Zn ions in the tea samples were 629.74, 17.75, and 37.38 mg/kg, whereas 3 toxic metals Cd, Cr, and Pb were 0.65, 1.02, and 1.92 mg/kg, respectively. The contents of heavy metals in the 3 types of tea were in the order of black tea > Oolong tea > green tea. Both PFOS and PFOA contents were low and PFOA content was higher than PFOS in the tea samples. The highest concentration of PFOA was 0.25 ng/g dry weight found in a Hunan green tea. The Principal component analysis was performed with the trace metals and PFCs to analyze the relationships of these indices. The results showed that black teas had higher trace metals and PFCs than green and Oolong teas, and the teas from Hunan and Zhejiang provinces had higher Pb and Cr than others.

This paper reports trace metals, and perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in wide range of tea products produced in the south China area. This paper also warns the low PFOS and PFOA pollution in tea.