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
Fluoride	0.8mg/L or less	Ion chromatography
Chloride	200mg/L or less	Ion chromatography or Titrimetric method