摘要：An investigation adopting coprecipitation with Zr (OH)4 followed by flame atomic absorption spectrometry was conducted to develop a facile method for quantitative determination of Ca and Mg in water. The results indicated that this method was quite satisfactory for determination of both Ca and Mg in water in concentrations of 0.04 to 10 ppm and 0.002 to 0.3 ppm, respectively, and that the presence of 10 ppm of each of Al3+, Cl-, Cu2+, Fe2+, K+, Na+, NO3-, PO43-, SiO32-, SO42-, and Zn2+ offered no significant interference, giving rise to more than 95% recovery ratios of Ca and Mg from tap water, river water, hot spring water, and sea water with less than 6% of S.D. values. The most crucial point of the operation procedure was the use of (1+1) ammonia water as the alkali agent instead of 4 N NaOH in the coprecipitation process. Comparison of the recovery ratios obtained by the coprecipitation method and those by the direct atomizing method revealed that the former method provided higher recoveries with smaller S.D. values.
