Analysis of anions and cations in drinking water samples by Capillary Ion Analysis

Abstract

The use of capillary ion electrophoresis (CIE, Waters’ tradename: Capillary Ion Analysis, CIA) for the analysis of four anions and four cations in drinking water samples available on the Malaysian market, such as natural mineral water, bottled drinking water and tap water, was investigated. In addition, zam-zam water (an underground water, much sought-after by Muslims and only available in Mekah, Saudi Arabia) was also analyzed. The anions analyzed were chloride, sulphate, nitrate and fluoride while the cations analyzed were potassium, calcium, sodium and magnesium. Results of this determination generally show a low content of anions and high content of calcium and magnesium in natural mineral water and non-detectable amounts of anions and cations in bottled drinking water. Out of the 15 mineral waters of different brands that were analyzed, four brands show anionic and cationic levels almost similar to that of tap water. With the exception of fluoride, an abnormally high level of both anions and cations were detected in all the zam-zam water samples analyzed, as compared to the other drinking waters.