Determination of nitrite in water by flow injection spectrophotometry

A determination for the nitrite in water by flow injection spectrophotometry was studied.The advanced CCD in the prototype was used as a detector.Nitrite was determined directly using the Griess diazo-coupling reaction and the formed azo dye was measured at 540 nm in the flow cell of the fibre-optic spectrophotometer.The best concentration of sulfanilamide and N-(1-naphthyl)-ethylenediamine is 1.0 and 60 g/L respectively.The linear range is 0.002～1.0 mg/L,the detection limit is 0.37 μg/L,the RSD is 2.0% and the recoveries of intirte added to the real samples ranged from 96.5%～101.2%.The determination frequency is 60 times per hour.This method is simple,quick and high sensitivity.