DETERMINATION OF HEAVY METALS CONCENTRATION IN DIFFERENT BRANDS OF BOTTLE WATER AVAILABLE IN ETHIOPIAN MARKETS BY USING FLAME ATOMIC ABSORPTION SPECTROSCOP

Abstract

Flame 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