ION EXCLUSION CHROMATOGRAPHY FOR THE TRACE ANALYSIS OF SODIUM, POTASSIUM, MAGNESIUM AND CALCIUM IONS IN WATER CONTAINING INTERFERING CONCENTRATIONS OF AMMONIUM IONS (CATION EXCHANGE, PARTITION CHROMATOGRAPHY)

<p>Ion Exclusion Chromatography has been investigated as a technique for separating trace quantities of sodium, potassium, magnesium and calcium ions in water containing interfering quantities of ammonia. Using water as eluent and a hydroxide-form strong-base anion exchange resin, the interfering ammonia was successfully separated from the metal ions. To effect a separation of calcium and magnesium ions, either individually or together, from sodium and potassium ions, the use of a complexing agent as eluent was required. It was not possible to separate sodium ions from potassium ions. To determine the optimum conditions for separation, various factors were investigated including: choice of resin, inclusion of methanol in the eluent, pH, choice of complexing anion, and concentration of eluent and sample ions.</p>