Abstract: Platinum electrodes modified with non-conducting films were assembled and used for the rapid amperometric detection of nitrites and nitrates in water by batch and flow injection analysis (FIA). Parameters such as the permeability of electropolymerised films to nitrites and nitrates, interference effects and recovery studies of these kinds of sensors have been optimized to demonstrate the analytical suitability of the proposed method. Contrary to the standard colorimetric method, which is based on carcinogenic reagents, the amperometric detection of nitrites and nitrates is very simple and rapid and does not require any reagent for nitrite detection. In addition, this method could be easily extended to the analysis of nitrites and nitrates in various types of samples such as food, soils, vegetables and fertilizers.

Abstract: One of the problems associated with an experimental technique in flow injection analysis is choosing the appropriate detection method and equipment that will best describe the selected topic. This paper discusses some theoretical considerations and presents a few practical designs of modular electrochemical cells used in connection with flow injection analysis systems.