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.

Sample : Tap water (Water), 100micro-L

1. F^–

2. Cl^–

3. NO₃^–

4. SO₄^2-

 Column : Shodex IC NI-424 (4.6mmID*100mm)
 Eluent : 8mM 4-Hydroxybenzoic acid + 2.8mM Bis-Tris + 2mM Phenylboronic acid + 0.005mM *CyDTA aq.
 Flow rate : 1.0mL/min
 Detector : Shodex CD
 Column temp. : 40°C

^* CyDTA: trans-1,2-Diaminocyclohexane-N,N,N’,N’-tetraacetic acid