HJ 668-2013 《Water quality.Determination of total nitrogen by flow injection analysis (FIA) and N-(1-naphthyl)ethylene diamine dihydrochloride spectrophotometry》 Related products

The HJ 668-2013 standard specifies a flow injection-muriatic acid naphthalenediamine Spectrophotometric method, spec-trophotometry for the determination of total nitrogen in water. It is suitable for the determination of total nitrogen in surface water, groundwater, domestic sewage and industrial wastewater. The method has a detection limit of 0.03 mg/L and a measurement range of 0.12 to 10 mg/L at a 10 mm optical path. The method is based on a chemical reaction. The nitrogen-containing compound is oxidized to nitrate and then reduced to nitrite, and finally reacts with muriatic acid naphthalenediamine to form a purple compound. Absorption measurement at 540 nm is performed.