SPECTROMETRIC DETERMINATION OF NITRITE IN AQUEOUS-SOLUTION BY THE DIAZOTIZATION-COUPLING METHOD WITH PARA-AMINOBENZOPHENONE-N-(1-NAPHTHYL)-ETHYLENEDIAMINE

Nitrite ion at low concentration is determined spectrometrically by diazotization of p-aminobenzo-phenone and coupling of the resulting diazonium cation with N-(l-naphthyl)-ethylene-diamine to form a reddish-violet coloured water-soluble azo dye with maximum absorption at 555 nm. The method is suitable for the determination of nitrite over the range of 0.04-1.00ppm. Beer's law is obeyed over this range of concentrations. The observed molar absorptivity and Sandell's sensitivity of the azo dye are 7.0 × 104lmoP' cm−1and 6.5 x I0-4μgcnrT-2, respectively. Interferences due to other ions were studied to test the selectivity. © 1990, Taylor & Francis Group, LLC. All rights reserved.