Simultaneous determination of the hardness and alkalinity in drinking water by inductively coupled plasma atomic emission spectrometry
HUO Jian-zhong1,DUAN Xu-chuan*2
1. College of Chemistry, Tianjin Normal University, Tianjin 300387, China; 2. Tianjin Key Laboratory of Animal and Plant Resistance,College of Life Sciences,Tianjin 300387, China
Abstract：The feasibility of simultaneous determination of hardness and alkalinity of drinking water by inductively coupled plasma atomic emission spectrometry (ICP-AES) was studied. the water sample was acidified off-line with diluted hydrochloric acid. The bicarbonates in water sample were in-situ converted into carbon dioxide, which was also dissolved in original water. Then, the solution was sampled by conventional single tube of inductively coupled plasma atomic emission spectrometer. The simultaneous sampling of CO2, Ca and Mg was realized at relatively low atomizer pressure. Among them, CO2 was sampled in gas state, while Ca and Mg were sampled in atomizing state. In this study, the bicarbonates with low sampling efficiency in atomizing method were converted into gas carbon dioxide, which had high sampling efficiency, thus the determination sensitivity of carbon was increased, realizing the accurate determination. The measured content of inorganic carbon was converted to the content of bicarbonates, so the alkalinity of drinking water was obtained. Meanwhile, the content of Ca and Mg was converted to the content of calcium carbonate to calculate the hardness of water. Under the optimal experimental conditions, i.e., atomizer pressure of 241.3 kPa and dilution ratio of 5 for water sample, the hardness and alkalinity of drinking water were simultaneously determined by this method. The found results were consistent with those obtained by titration method.
霍建中,段旭川. 电感耦合等离子体原子发射光谱法同时测定饮用水的硬度和碱度[J]. 冶金分析, 2013, 33(8): 55-58.
HUO Jian-zhong,DUAN Xu-chuan. Simultaneous determination of the hardness and alkalinity in drinking water by inductively coupled plasma atomic emission spectrometry. , 2013, 33(8): 55-58.
