LEVELS OF ESSENTIAL AND NON-ESSENTIAL METALS IN ETHIOPIAN OUZO

Abstract

The levels of selected metals (Na, Ca, Mg, Fe, Zn, Mn, Cr, Co, Cu, Ni, Cd and Pb) in five different brands (Kokeb, National, Liyu Addis, Victoria and Balezaf) of Ethiopian ouzo sampled from different supermarkets in the capital city Addis Ababa were determined. 10 mL of ouzo samples were digested by using 2 mL of HNO₃ and 5 mL of H₂O₂ for 90 minutes at a temperature of 180°C and the levels of the minerals in the digests analyzed by flame atomic absorption spectrometer. The following results were recorded in mg/L for each five ouzo brands Na (8.529–18.194), Ca (8.330–12.830), Mg (1.345–10.977), Fe (0.942–2.881), Zn (0.642–2.215), Mn (0.015–0.225), Cr (0.054–0.121), Co (0.072–0.130). Cu (0.212 mg/L) was detected only in Kokeb brand while Ni and Cd were below the method detection limit in all the five brands of ouzo analyzed. The toxic metal Pb (0.127–0.507 mg/L) was detected in all the five brands of ouzo samples. The level of Na was the highest in all the brands followed by Ca and Mg respectively except for Kokeb ouzo in which the level of Mg was higher than Ca. Among the trace elements, Zn was found to be highest next to Fe followed by Mn and Co. The levels of metals were higher in Liyu Addis ouzo compared to the other brands. Generally, ouzo contains some nutritionally essential minerals in large quantity so that it can be used as one source of minerals. Non-essential and trace metals were either not detected or found only in smaller quantity. But non-essential metal Pb was detected in all ouzo brands which ranged from 0.13 to 0.51 mg/L. Thus, periodic determinations are advisable in view of the potential medium and long-term risks associated with Pb contamination.