Abstract

In order to control the pollution of nitrite, a simple, accurate and sensitive reverse reference flow injection analysis (rrFIA) spectrophotometric method for determination of nitrite in tannery effluent is proposed. In acid conditions, nitrite with sulfanilamide is diazotized, and then the diazo material is coupled with N-1-naphthyl ethylenediamine hydrochloride (NEH) to form a red product. The absorbance of the complex compound is measured at 540nm. Chemical factors and rrFIA variables affecting the system are also discussed. Under the optimal conditions, the linear range of this method was 0-50.0 g l-1; the detection limit was 0.03 g l-1; the relative standard deviation was 0.844%. This method was suitable for automatic and continuous analysis, and successfully applied to determine the content of nitrite in tannery effluent.