Regulation for Water Supply

Criteria values and measurement conditions determined by the japanese regulations (the administrative order of the Ministry of Health, Labour and Welfare #101 (May 30, 2003) and #261 (July 22, 2003)) are shown in the table below. When the method is adopted, it is necessary that its detection limit be less than one tenth of the criteria values. IC I-524A, NI-424 and SI-90 4E (columns for anions analysis) satisfy this condition.

Regulations for water supply introduced on
April, 2004

Item Criteria value Usable method
Nitrate nitrogen
& Nitrite nitrogen
10mg/L or less
Ion chromatography
0.8mg/L or less
Ion chromatography
200mg/L or less
Ion chromatography or
Titrimetric method