Determination of essential and toxic heavy metals in barley (Hordeum vulgare) cultivated in selected places in Amhara Region, Ethiopia

Abstract

Barley (Hordeum vulgare. L) is used as food, for feeding animals and for malting in the world and in Ethiopia. The levels of essential metals (K, Mg, Ca, Na, Zn, Fe, Ni, Mn, Cu, Cr and Co) and toxic heavy metals (Pd and Cd) in barley samples collected from East Gojjam, Awi zone and West Gojjam, Ethiopia, were determined by flame atomic absorption spectrometry. For the determination, first 0.5 g barely sample was digested using mixtures of 2 mL of HNO₃, 1 mL of HClO₄ and 1 mL of H₂O₂ at 210^oC for 2:30 hr based on the optimized wet digestion procedure. The optimized wet digestion procedure was evaluated using standard addition (spiking) method and an acceptable percentage recovery was obtained. The mean metal concentration ( mg/kg dry weight basis) ranges in barley are : K (4094–12238), Mg (827–983), Ca (320–886), Na (49.2–62.3), Zn (33.7–76.7), Fe (15.7 – 106), Ni (3.78–27.6), Mn (8.83–13.7), Cu (5.83–10.5), Cr (4.33–6.11), Co (3.38–5.83), Pb (1.44–2.33) and Cd (0.98–1.55). The results were compared with values reported in the literature.