New electrochemical sensors for detection of nitrites and nitrates

Platinum electrodes modified with a cellulose acetate membrane or with poly (1,8-diaminonaphthalene) film were assembled and used for rapid amperometri c detection of nitrites and nitrates in water by batch and flow injection a nalysis. Parameters such as the permeability of the electropolymerised films to nitr ites and nitrates, interference effects and recovery studies of these kinds of sensors have been optimised to demonstrate the analytical suitability o f the proposed method. Contrary to the standard colorimetric method, which is based on carcinogeni c reagents, the amperometric detection of nitrites and nitrates is very sim ple and rapid and does not require any reagent for nitrite detection. Also, this method could be extended easily to the analysis of nitrites and nitra tes in various types of samples such as food, soils, vegetables and fertili sers. (C) 2001 Elsevier Science B.V. All rights reserved.