Ethylenediamine (0.1 % v/v of 50 mg/mL) is added to water samples to prevent HCl production from the reaction between residual chloride and chlorous acid. Ion chromatography (cation) column, IC YS-50 was used to separate mono- and di-valent cations in the presence of ethylenediamine. 10 % ACN was added to the mobile phase to shorten ethylenediamine retention. Addition of crown ether can improve the separation of Na⁺ and NH₄⁺ , but this will increase the ethylenediamine retention.


Sample : Cation std.,10 μL
1. Li⁺ 2 mg/L
2. Na⁺ 10 mg/L
3. NH₄⁺ 10 mg/L
4. K⁺ 20 mg/L
5. Mg²⁺ 10 mg/L
6. Ca²⁺ 20 mg/L
7. Ethylenediamine, EDA 50 mg/L

Column       : Shodex IC YS-50 (4.6 mm I.D. x 125 mm) 
Eluent       : (A); 4 mM Nitric acid aq./CH3CN=90/10
               (B); 4 mM Nitric acid + 1.5 mM 18-Crown 6-ether aq./CH3CN=90/10
Flow rate    : 1.0 mL/min
Detector     : Non-suppressed conductivity
Column temp. : 40 °C