Tap Water (7) (NI-424)

The administrative order of the Ministry of Health, Labour and Welfare #261 (July 22, 2003) specifies the acceptable levels for F^-, Cl^-, NO₂^- and NO₃^-. Their concentrations are measured using ion chromatography. Here, anions in tap water were analyzed using IC NI-424 though NO₂^- could not be detected in tap water.
Please refer to 'Regulation for Water Supply'.


Sample : Tap water (Water), 50micro-L
1. F^-
2. Cl^-
3. NO₃^-
4. SO₄^2-

Column       : Shodex IC NI-424 (4.6mmID*100mm)
Eluent       : *18mM 4-Hydroxybenzoic acid + 2.8mM Bis-Tris + 2mM Phenylboronic acid + 0.005mM *2CyDTA(pH4.2) 
Flow rate    : 1.0mL/min
Detector     : Shodex CD
Column temp. : 40deg-C

^*1 The prescribed pH can be obtained by mixing the reagents in the composition described here.
^*2 CyDTA: trans-1,2-Diaminocyclohexane-N,N,N',N'-tetraacetic acid