Monovalent and Divalent Cation Standards (8) (Ethylenediamine Containing Sample)

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.,10micro-L
1. Li⁺ 2mg/L
2. Na⁺ 10mg/L
3. NH₄⁺ 10mg/L
4. K⁺ 20mg/L
5. Mg²⁺ 10mg/L
6. Ca²⁺ 20mg/L
7. Ethylenediamine, EDA 50mg/L

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