Determination of concentration of some essential and heavy metals in roots of Moringa stenopetala using flame atomic absorption spectroscopy

Abstract

This study is aimed at determination of concentration of essential (Ca, K, Na and Mg) and heavy (Cd, Cr, Pb, Hg, Cu and Zn) metals using Flame Atomic Absorption Spectroscopy (FAAS) of samples taken from fresh roots of Moringa stenopetala. A wet digestion method involving use of mixture of (HCl and HNO 3 , ratio 3:1) and 10 ml of 30% H 2 O 2 at an optimum temperature and time duration was deployed during sample preparations. Results show that concentration of essential elements Mg, Ca, Na, and K range from 10.12 to 10.99 mg/kg, 2.6 to 5.64 mg/kg, 4.3 to 5.26 mg/kg, and 1.26 to 1.77 mg/kg, respectively. Among the heavy metals, concentration of Cu fall in the range of 0.81 _ 1.44 mg/kg while that of zinc fall in the range of 0.37 _ 2.34 mg/kg, both lying below toxic level. The levels of toxic metals (Cd, Cr, Pb and, and Hg) were not detected. The results of the study indicate that the concentration of the entire essential and heavy metals are below the range of WHO/FAO limits.