Departments of Physics
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Item ANALYSIS OF HEAVY METAL CONCENTRATIONS IN COATINGS OF SCRATCH LOTTERY CARDS AND SCRATCH PHONE RECHARGE CARDS IN ETHIOPIA USING FLAME ATOMIC ABSORPTIONS SPECTROSCOPY(HAWASSA UNIVERSITY, 2024-06) KEDIR EDAO WABEThis research work was focused on the presence and level of heavy metals in coatings of scratch mobile cards and lottery cards in Ethiopia using flame atomic absorptions spectroscopy .The study mainly stressed on heavy metals such as Copper, Lead, Manganese, Chromium, and Nickel, so that the coatings of this scratch mobile cards and lottery cards were acidic digested for the determinations of the presence and levels of heavy metals concentrations. According to the laboratory results the concentrations of heavy metals in certain amounts in all these heavy metals indicated above and when we saw the levels and concentration of this heavy metals one by one with a value Cu(0.954,1.07) ,Pb(0.085,0.071), Mn(0.084,0.055), Cr(0.073,0.060) and Ni(0.051,0.041) in ppm respectively for both mobile recharge and lottery cards. This indicated that heavy metals Cu had the largest value as we compared with heavy metals and heavy metals Ni had the least and the rest heavy metals were next to the copper metal respectively for both mobile recharge cards and lottery cards and the calibrations of concentration to absorbance would obtained the result and the concentration of heavy metals in coatings of scratch mobile recharge cared and lottery cards in standards solution and its within R2 (0.994-0.999). Although the concentrations of all this heavy metal in the scratch cards are low, over time they can accumulate on the environment if not properly disposed, and can cause health problems as they are poisonous and dangers to human health when taken above the limit set by WHO. Therefore public awareness become advised not to use finger nails to scratch mobile recharged card and lottery cared rather it is advisable to use sharp edge materials in order to scratch this mobile recharge cards and lottery cardsItem DETERMINATION OF HEAVY METALS CONCENTRATION IN DIFFERENT BRANDS OF BOTTLE WATER AVAILABLE IN ETHIOPIAN MARKETS BY USING FLAME ATOMIC ABSORPTION SPECTROSCOP(2024-11) : AYENEW BERHANU LIBENFlame atomic absorption spectrometry (FAAS) is a crucial analytical technique widely used in environmental studies to detect and quantify heavy metals. In this research we used FAAS to determine the concentrations of Ni, Cu, Cr, Co, and Pb in 18 different brands of bottled water collected from Ethiopian’s markets. Samples were stabilized with 2% nitric acid and analyzed using flame atomic absorption spectroscopy (FAAS) after precise calibration with standard solutions. The concentrations of Ni, Cu, Cr, Co, and Pb ranged from 0.021 - 0.068 mg/L, 0.021 - 0.084 mg/L, 0.044 - 0.049 mg/L, 0.00 mg/L, and 0.005 – 0.0093 mg/L respectively. The method validation demonstrated excellent linearity, with correlation coefficients (R2 ) of 0.9994, 0.9995, 0.9998, 0.9990, and 0.9999 for Ni, Cu, Cr, Co and Pb, respectively. Precession (%RSD) was within acceptable limits ranging from 0.21% to 8.5% for Ni, 0.0% to 8.8% for Cu, 0.2% to 9% for Cr, and 0.0% to 13.04% for Pb. These values are acceptable as compared to the standard acceptable value of R 2 > 0.999 for linearity and %RSD ≤ 16% for precision based on ICH value. Recoveries (accuracy) ranged from (92.6 – 101.7) % which is within the acceptable range of recovery test of 90% - 110% based on ICH values. The concentration of heavy metals found in all bottled water samples are below the recommended World Health Organization’s (WHO’s) and Ethiopian’s quality guidelines for drinking water for heavy metals so that there is no safety compliance with respect to thi