Ion Chromatographic Determination of Sodium, Potassium, Magnesium and Calcium Ions in River Water

The factors affecting the ion chromatographic separation of the alkaline earth metal cations on silica gel columns were investigated using different types of dicarboxylic acids as retention modifiers. The mobile phase pH and acid concentration showed marked influence on the separation of the analytes. When a 0.002mol dm-3 lithium oxalate solution of pH 7 was used as a mobile phase, the major four cations in river water (Na+, K+, Mg2+ and Ca2+) were completely separated on a Nucleosil column (50mm×4.6mm id.) within about 16min.