Toxic and essential elements in five tree nuts from Hangzhou market, China.

In this study, a total of 35 tree nut samples of walnut, pecan, pine seed, hickory nut and torreya were obtained from 5 farm product markets in Hangzhou, China, and investigated for essential (Cr, Mn, Fe, Mo, Cu, Zn, Se and Sr) and toxic (Al, As, Cd and Pb) elements by inductively coupled plasma-mass spectroscopy. Mean elemental concentrations of different tree nuts were in the following ranges: Cr 0.26-0.78 mg kg ^-1 , Mn 42.1-174 mg kg ^-1 , Fe 33.7-43.9 mg kg ^-1 , Mo 0.11-0.48 mg kg ^-1 , Cu 10.3-17.6 mg kg ^-1 , Zn 21.6-56.1 mg kg ^-1 , Se 0.015-0.051 mg kg ^-1 , Al 1.44-37.6 mg kg ^-1 , As 0.0062-0.047 mg kg ^-1 , Cd 0.016-0.18 mg kg ^-1 and Pb 0.0069-0.029 mg kg ^-1 . The estimated provisional tolerable daily intake of Al, As, Cd and Pb was much lower than the provisional tolerable daily intake.