Spectrophotometric determination of nitrite in environmental samples using a new reagent system

Abstract

A sensitive and rapid spectrophotometric method has been investigated for the trace determination of nitrite in potable and polluted water. The method is based on the Griess reaction in which nitrite is diazotised with sulphadiazine in acid medium and then coupled with N-(1-naphthyl)-ethylenediamine dihydrochloride to give a purple coloured azo dye, having theta-max at 545 nm and a molar absorptivity of 6.9 x 10sup(4) 1.mol sup(-1) cm sup(-1). The proposed reagent system has also been used as spot reaction for the qualitative determination of nitrite in effluents (limit of identification, 0.025 mu g).