鉱泉の研究 (第1報)

Abstract

Determination of sodium ion by flame photometry by direct ignition of hot spring and mineral spring water, using the standard calibration curve of standard sodium chloride solution gives negative error which cannot be disregarded, with the exception of a common salt spring. Good analytical result can be obtained if the spring water is treated at pH 4 to remove carbon dioxide and hydrogen sulfide, passed through an R-Cl type column of ion exchange resin (Amberlite IRA-410), thereby changing all the anions in the sample water to chlorine ion, and finally submitted to flame photometry. This method can be applied widely to the majority of neutral salt springs in Japan, excluding the acid, alum, and acid alum-vitriol springs. It is better than the chemical determination of sodium in that it gives better accuracy and the shorter time required. The weak acid components which cannot be substituted by the foregoing resin can be disregarded.