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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/2097

Advisors: Prof. B. S. Chandravanshi
Keywords: FAAS
Non-essential and Toxic metals
Essential metals
Croton leaves infusion
Croton leaves powder
Croton macrostachyus
Copyright: Jul-2010
Date Added: 2-May-2012
Publisher: aau
Abstract: The concentration of nine essential metals (Ca, Mg, Fe, Mn, Zn, Cu, Co, Cr, Ni) and two non- essential and toxic metals (Cd, Pb) were determined in leaves of the same species of Croton macrostachyus collected from four different areas (Akaki, Abomsa, Bonga and Dilla) and infusions of leaves collected from Akaki using flame atomic absorption spectrometry (FAAS). An optimized digestion procedure was selected based upon less reagent consumption, digestion time and mass of sample using 2 mL of HNO3 and 2 mL of HClO4 with 2:30 hours total time at temperature round 270 oC for digestion of 0.5 g of powder sample while 4 mL of HNO3 and 1 mL of HClO4 with 2:30 hours total time for 25 mL infusion evaporated up to 3 mL. The validity of the optimized procedure was evaluated by the analysis of spiked samples whose recovery was in the range 92-103% for the Croton leaves powder and 94-105% for the infusion samples. The mean concentration range of each metal in Croton leaves powder samples were Ca (1202–7040 μg/g), Mg (271–2961 μg/g), Fe (169–581 μg/g ), Mn (157–1776 μg/g), Zn (19.7–60.5 μg/g), Cu (6.31–18.6 μg/g), Co (19.7–34.5 μg/g), Cr (21.3–87.5 μg/g), Ni (2.65–26.2 μg/g), Cd (1.08 – 0.75 μg/g) and Pb (10.5–21.9 μg/g) for the Croton leave powders and Ca (467–1087 μg/g), Mg (13.9–52.6 μg/g), Fe (3.43–6.53 μg/g), Mn (2.17–3.42 μg/g), Zn (2.24–9.51 μg/g), Cu (2.17– 2.54 μg/g), Co (2.15–2.83 μg/g), Cr (2.61–13.44 μg/g), Ni (2.17–2.80 μg/g), Cd (0.207 μg/g) and Pb (0.371–2.07 μg/g) for the infusion samples. The Croton leave powders contained more amounts of metals than the infusions and it was rich in Ca to a largest extent followed by Mg and Fe for Akaki and Abomsa and for Bonga and Dilla sites, respectively. Fe concentration was determined to be the highest followed by Cr and Zn out of the trace microelements Croton leaves powder taken from Akaki and Abomsa whereas Mn concentration was the second next to Ca for Bonga and Dilla sites. The metals were observed to leach in to the infusions at a rate highest for Ca (61.5%) in the 24 h infusion and lowest for Fe (1%) in the 3 h infusion. The concentrations of metals in the Ethiopian Croton macorostachyus are comparable to values for other medicinal plants reported in other parts of the world. Poor correlation was observed between Mn as well as x Co with almost all metals Croton leave powder samples and good correlation between all metals in Croton leaves infusion was observed.
URI: http://hdl.handle.net/123456789/2097
Appears in:Thesis - Chemistry

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