Levels of Essential and Non-essential Metals in Garlic (Allium sativum L.) Samples Collected from Different Locations of East Gojjam Zone, Ethiopia

Abstract

The concentrations of essential metals (Na, K, Ca, Mg, Fe, Zn, Mn, Cu, Co and Ni) and non-essential metals (Cd and Pb) in garlic samples were determined using flame photometer for Na and K, and flame atomic absorption spectrometry (FAAS) for the rest of the metals. The samples were collected from four agricultural areas (Debre Markos, Dejen, Bichena and Debre Werk), East Gojjam Zone, Ethiopia. Wet digestion method using a mixture of 4 ml HNO3 and 1 ml HClO4 was used for digestion of the samples. The results obtained revealed that the concentrations of metals in the garlic samples in mg/kg dry weight were in the range of: Na (244-306), K (6514-8592), Ca (3142-4004), Mg (798-1322), Fe (136-172), Zn (57.6-83.6), Mn (27.2-27.5), Cu (8.15-13.4), Co (11.4-28.3), Ni (14.1-19.6), Cd (0.10-0.14) and Pb (0.68-1.43), respectively. In general, the levels of metals in Allium sativum collected from all sampling site was found to be decreased in the order of: K > Ca > Mg > Na > Fe > Zn > Mn > Co > Ni > Cu > Pb > Cd. The levels of metals determined in the analyzed garlic samples were found below the WHO maximum permissible limit; hence they are safe for human consumption and can be considered as good sources of essential nutrients.

Keywords: Essential and non-essential metals, allium sativum (Garlic), wet digestion, FAAS, flame photometer