Multivariate characterization of elements accumulated in Wolfiporia extensa mushroom from Yunnan province of China

Dried sclerotia of Wolfiporia extensa have been used as medicine in Asia from Eastern Han Dynasty, and also used as traditional snack called "fulingjiabing" in Beijing, China. In this paper, 18 macro and trace elements (Ag, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Li, Mn, Ni, Pb, Rb, Se, Sr, V, and Zn) in both flesh and peel of Wolfiporia extensa from seven sites of Yunnan province in China were determined by inductively coupled plasma mass spectrometer. The average recovery rates of certified reference materials for GBW10015 (spinach leaves) ranged from 90.5 to 113%, for GBW10028 (citrus leaves) from 92.8 to 106%, and for GBW07603 (bush branch and leaves) from 83.3 to 114.6%. Generally speaking, the concentration of all elements determined was at common level. The results of this survey indicate that mineral compositions in peel were higher than in flesh. In peel, the contents of investigated trace metals in mushroom samples were found to be in the range of 1,660-13,400 mu g. g(-1) dry matter (dm) for Fe and 29.6-710 mu g.g(-1) dm for Mn. The mean contents of Cr, Cu, Rb, V, and Zn in peel were between 10 and 20 mu g.g(-1) dm, followed by As, Co, Li, Ni, Pb, Se, and Sr with mean contents between 1 and 10 mu g.g(-1) dm, while Ag, Cd, and Cs had mean contents of < 1 mu g.g(-1) dm. In flesh, the concentration of Fe was in the range of 54-900 mu g.g(-1) dm, and it was 1.5-49 mu g.g(-1) dm for Mn, followed by Ba, Cu, Rb, and Zn in the range of 1 to 10 mu g.g(-1) dm, while for Ag, As, Cd, Co, Cr, Cs, Li, Ni, Pb, Se, Sr, and V it was < 1 mu g.g(-1) dm. The concentration of toxic elements, such as As, Cd, and Pb, in both flesh and peel was below the permissible limits of World Health Organization. However, As and Pb contents in peel were higher than the limits permitted in the Chinese Pharmacopoeia. The results of principal component analysis showed that the flesh of Wolfiporia extensa from all the seven sites of the Yunnan province tend to cluster together, most probably because the origin of mineral elements in both flesh and peel is wood substrate (old and dead pine trees).