Photometric Assay of Nitrite in Various Samples

Abstract

The assay is based on the reaction of nitrite in acidic medium with m-nitroaniline to form the corresponding diazonium ion which is coupled with N-(1-naphthyl)ethylenediamine to form a stable purplish azo dye that shows maximum absorption at 530 nm. Beer's law is obeyed over the concentration range 0.04-1.0 ppm. The molar absorptivity is (4.6x104l.mol-1.cm-1), and Sandell's sensitivity index of (0.1 ng. cm-2).The proposed method has been applied to the determination of nitrite in meat, water and soil.