Monovalent and Divalent Cations Analysis in Tap Water (Ethylenediamine Containing Sample)

Chloric acid should be analyzed by ion chromatography for water quality standard in accordance to the Ministry of Health, Labor and Welfare in Japan. 1mL of Ethylendiamine (EDA) solution (50mg/mL) is to be added into 1L sample, to prevent generation of chloric acid through the reaction between chlorous acid and residual chlorine. Monovalent and divalent cations in tap water were analyzed by IC YS-50.

Sample : 50micro-L
Cation std. containing EDA 50mg/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

Sample : 50micro-L
Tap water (Water) containing EDA 50mg/L
2. Na+
3. NH4+
4. K+
5. Mg2+
6. Ca2+
7. Ethylenediamine, EDA 50mg/L

Column       : Shodex IC YS-50 (4.6mmID*125mm) 
Eluent       : 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