[Analysis of 23 mineral elements in tea samples collected from China and Japan by using ICP-AES and ICP-MS combined with a closed decomposition].

After a closed decomposition, the concentrations of Al, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, La, Mg, Mn, Na, Ni, Pb, Rb, Sb, Sr, Th, U, Y and Zn in thirteen Chinese tea samples and six Japanese tea samples were analysed by using ICP-AES and ICP-MS, a tea standard reference material (GBW07605) was used to verify the accuracy and the precision of analytical method. It was demonstrated that a closed decomposition can help to get good results for the concentrations of mineral elements in tea samples. Compared with those in Japanese tea samples, the concentrations of Cd, Co, Cr, Cs, Fe, Pb, Rb, Sb, Th, U and Zn in Chinese tea samples are significantly high, which means the atmosphere in China is contaminated by heavy metal particles more severely than that in Japan. Moreover, it was found that the concentrations of many mineral elements in tea samples correlate each other.