%0 Journal Article
%T Levels of essential and non-essential metals in Rhamnus prinoides (Gesho) cultivated in Ethiopia
%A A Gebre
%A B Singh Chandravanshi
%J Bulletin of the Chemical Society of Ethiopia
%D 2012
%I Chemical Society of Ethiopia
%X The objective of this study was to assess the levels of essential and toxic metals in leaf and stem of Rhamnus prinoides which are used for bitterness of local alcoholic beverages in Ethiopia and as traditional medicine in some African countries. Levels of essential metals (Ca, Mg, Cr, Mn, Fe, Co, Ni, Cu and Zn) and toxic metals (Cd and Pb) in the leaves and stems of Rhamnus prinoides (Gesho) cultivated in Ethiopia were determined by flame atomic absorption spectroscopy. Known weights (0.5 g) of dried samples were digested with the optimized mixture of HNO3, H2O2 and HClO4 on a Kjeldahl apparatus with a reflux condenser. The efficiency of the optimized procedure was validated by spiking experiment and the percentage recovery for all the metals was in the range of 92每103% for leaf samples and 91每103% for the stem samples. The levels (mg/kg) of the metals were found to be: Ca (6304每22236), Mg (3202每5706), Cr (5.08每20.6), Mn (8.12每17.9), Fe (47.9每187), Co (22.2每42.1), Ni (12.8每27.3), Cu (6.5每73.0), Zn (12.2每43), Cd (0.81每3.10), and Pb (17.7每25.0) in the leaf samples and Ca (3601每5675), Mg (2635每5528), Cr (ND每16.3), Mn (2.16每3.98), Fe (22.0每124), Co (18.7每91.7), Ni (9.68每19.2), Cu (16.8每233), Zn (17.4每28.2), and Cd (ND每1.56) in the stem samples. However, the levels of Cr and Cd in stem samples at one and two sample sites, respectively, and the levels of Pb in stem samples at all sample sites were below the method detection limit. This study showed that the leaf and stem of R. prinoides (Gesho) are good sources of essential minerals and virtually free from toxic metal Cd but not from Pb in the leaf.   KEY WORDS: Rhamnus prinoides, Gesho, Leaf, Stem, Minerals, Alcoholic beverages, Ethiopia   Bull. Chem. Soc. Ethiop. 2012, 26(3), 329-342. DOI: http://dx.doi.org/10.4314/bcse.v26i3.2
%U http://www.ajol.info/index.php/bcse/article/view/80262