Levels of Common Ions in Bottled Mineral Waters Consumed in Addis Ababa, Ethiopia

Abstract

The inorganic compositions of nine brands of bottled mineral water (Ambo, Aquaddis, Highland, Abyssinia, Aqua Safe, Crystal, Kool, Oasis and Real Springs) and municipal water samples from different sources that are consumed in Addis Ababa (Ethiopia) were determined using standard methods. Flame atomic absorption spectrometry was used for the determination of heavy metals (Fe, Zn, Cu, Cr, Cd and Pb); Cu, Cr, Cd and Pb were not detected in all the samples. Ion chromatography was used for the determination of common cations (Na⁺, K⁺, Ca²⁺, and Mg²⁺) and common anions (F^-, Cl^-, NO₃^-, SO₄^2- and PO₄^3-) in the mineral water and municipal water samples. Common cations were found to be higher in Ambo mineral water than other mineral water samples, some of the anions were not detected in some of the mineral water samples; phosphate was not detected in all the samples. Fe and Zn were in higher levels in municipal water as compared to mineral waters and the reverse was true in the case of common cations and anions. Some brands of bottled mineral water were found not to comply with international guidelines for drinking water with respect to trace metals (e.g., Zn, Cu, Cr, Cd and Pb) and some anions (e.g., F^-, NO₃^-, PO₄^3-) and may not be suitable for babies and people suffering from heart or kidney diseases. Some physical parameters, pH and electrical conductivity of each water sample were also determined; pH in some samples was found to be below the lower limit of who’s guideline.