Determination of Selected Essential and Toxic Metals in the Leave of Moringa Oleifera of Pawi District, Benishangul Gumuz Regional State, Ethiopia

Abstract

Leave of Moringa oleifera was collected from Pawi district of Metkel Zone, Benishangul Gumuz Regional state,Ethiopia. It was digested by wet digestion method using mixture of HNO 3, H 2O2 and HCl and Concentration of selected essential (Fe, Cu, Zn & Mn) and toxic heavy metals (Cd & Pb) were determined by flame atomic absorption spectroscopy (FAAS). For quantitative determination of the target analytes, external calibration curves utilized were exhibited acceptable coefficient of deterimination ,r 2 ,0.996 or better. The mean concentration of the metals in the studied Moringa Oleifera ranges from 0.05 - 0.17 mg/kg, 2.92 - 4.98 mg/kg, 0.04 - 0.06 mg/kg, 0.16 - 0.38 mg/kg, 0.40 - 0.54 mg/kg for Pb, Fe, Cu, Zn and Mn, respectivily; however Cd was not detected.The efficiency of the method was also evaluted using recovery studies by spiking known amount of the standered to the sample before wet digestion and satisfactory recoveries in the range of 86-116% were obtained. The obtained results indicated that the concentrations of the studied metals are below the primissible limit of WHO/FAO.Therefore,the consumption of the Moringa leave of the study area could not posse health problem to the consumers.