Flow-injection Spectrophotometric Determination of Nitrite in Water Samples

Department of Chemistry, University of Balochistan, Quetta-Pakistan Institute of Biochemistry, University of Bal chistan, Quetta-Pakistan Manuscript received 29 August 1991, revised 26 December 1991. accepted 27 January 1992 A sensitive and rapid method is described for the determination of nitrite. Nitrite is reacted with 4-aminosalicylic acid in acidic medium to give diazonium ions and merged with a coupling agent (1 naphthol) in alkaline medium resulting in the formation of azo compound quantified spectrophoton3etrically at 515 nm This method allows the determination of nitrite concentration in the range of 0 05 µg ml-1 with a sampling rate of 180 h-1 at a relative standard deviation of ≤ 1%