Abstract:
Determination of trace heavy metals level with high accuracy and precision is one of the most
important concerns of the analytical methodology as they pose health threat at high
concentrations. The aim of this study was to analyze selected trace heavy metals concentration in
Teff grain samples collected from Minjar Shenkora Woreda, North Shewa Zone, Amhara
Regional State, Ethiopia using Inductively Coupled Plasma Optical Emission Spectrometer
(ICP-OES). A wet digestion procedure using mixtures of HNO3 and HCl was developed for
decomposition of powdered Teff sample. The Teff grains samples were collected from the three
widely Teff growing Kebeles (Namely:Ameti, Menber and Adama) of Minjar Shenkora for the
analysis of eight heavy metals such as iron (Fe), manganese (Mn), zinc (Zn), copper (Cu),
Chromium (Cr), Cadmium (Cd), lead (Pb) and nickel (Ni) by using ICP-OES. The average
concentration of heavy metals in White teff, Red and Mixed teff respectively were: Fe (90.547,
208.363, 104.147 ), Mn (30.631, 65.410, 28.023), Zn (13.959, 27.993, 13.062), Cu (12.304,
5.413, 2.011), Cr (5.025, 4.801, 5.527), Cd (0.012, 0.004, 0.008 ), Pb (< 0.004,< 0.004, <
0.004) and Ni (1.207, < 0.002 , < 0.002 ) mg/L. The order of uptake of heavy metals
concentration by three types of teff grains were Fe > Mn > Zn > Cu > C r > Cd > Pb > Ni. In
addition, the mean concentrations of heavy metals in teff samples obtained from the three kebeles
farmland decreases in the following order: Fe > Zn > Mn > Cu > Cr > Co > Ni > Pb > Cd. The
author concluded that the levels of heavy metals determined in the analyzed teff samples were
found below the permissible limits set by FAO/WHO. Hence they are safe for human
consumption at the present concentrations in all the three Teff varieties. A statistical analysis of
variance (ANOVA) using excel and SPSS software revealed that there is a significant difference
between the mineral content of the three teff types at 95% ( p < 0.05) CL.
