Determination of Nitrite in Vegetable by Catalytic Kinetic Photometry

A catalytic kinetic spectrophotometric method for the determination of nitrite with cetylpyridine bromide surfactant as sensitizer was developed based on the catalysis of NO - 2 to the discoloring reaction of pyronine B oxidized by potassium bromate in dilute H 3PO 4 solution,which increases the sensitivity by about 2.5 times.The linear range is 0.005—0.25mg/L with the detection limit of 0.004mg/L.The method was applied to the determination of trace nitrite in water and vegetable samples with satisfactory results.