Parameter optimization for metal (Mn, Cu, Ni) digestion from Cactus opuntia leaf.

ABSTRACT : Cactus is a member of the Cactaceae family, which was originated in Mexico and grows in many other parts of the world, such as Africa, Australia and the Mediterranean basin. Cactus is generally known as a plant has great economical value, which occurs in the dry zone of north Ethiopia, mostly in south tigray and east tigray. It is a popular fruit all over tigray. Heavy metals are natural components of the earth’s crust and they can enter the water and food cycles through a variety of chemical and geochemical processes. Living organisms require trace amounts of some heavy metals, including Co, Cu, Fe, Mn, Mo, Ni and Zn. Excessive levels of these metals, however, can be detrimental to living organisms. This paper was focus on level of the metals and to investigate the effect of digestion temperature and time on the concentration metals. The method was developed by adjusting reagent volume and by varying the time and temperature, then the digested sample was run into atomic absorption spectrophotometer (AAS). Sample leaf collected from Kidane Mhiret (KM), the concentration of metals with respect to time was found in the order of Cu>Mn>Ni but, with respect to temperature Ni>Mn>Cu. Therefore, in the leaf of cactus in KM, Mn abundantly existed as the micronutrients. At the MK the concentration of metals with respect to time was found in the order of Ni >Cu >Mn but, with respect to temperature Mn>Cu>Ni. Therefore, in the leaf of cactus in MK, Mn abundantly existed as the micronutrients .