Concentration levels of selected metals in the leaves of different species of thyme (T. schimperi and T. vulgaris) grown in Ethiopia.

The contents of some selected metals Ca, Mg, Fe, Mn, Co, Cu, Zn, Ni, and Cd in different thyme leaf samples widely consumed in Ethiopia were determined by flame atomic absorption spectroscopy (FAAS) after acid digestion with 1:1 HNO(3)/HClO(4) for 3 h at a temperature of 240°C by a Kjeldahl apparatus hot plate digester. The level of the nutrients in the four samples ranged from 1,239-2,517 μg/g, Ca; 1,524-1,786 μg/g, Mg; 728-2,517 μg/g, Fe; 37.7-114 μg/g, Mn; 2.59-4.3 μg/g, Co; 7.69-9.3 μg/g, Cu; 8.7-52 μg/g, Zn; and 9.83-14.2 μg/g, Ni; respectively. While the level of toxic metal Cd in the four samples ranged from 0.87-1.3 μg/g. The concentration of Ca was higher than the other metals in the three samples and Cd was the least of all the metals in the analyzed samples. The overall reproducibility of the method obtained from spiking experiment was within the range ±10%. This result will complement available data on food composition in Ethiopia.