Application of an 800 Gold Microelectrode Array for Rapid Voltammetric Detection of Nitrite Pollution in Environmental Waters

A simple voltammetric procedure for direct determination of nitrites in natural water samples is described. Measurements are carried out in an inert medium of 0.1 M KCl. The procedure is based on the oxidation of N(III) to N(V) as a result of a change in electrode potential from +0.40 V to +0.96 V. The use of a combined electrode consisting of approximately 800 gold microelectrodes enables undisturbed determinations to be performed in the presence of high concentrations of organic compounds at a level of 20 mg l −1 . The calibration plot for NO 2 − was linear in the range from 2 × 10 −6 to 8 × 10 −4 M with a detection limit of 6 × 10 −7 M. The proposed procedure was successfully applied to nitrate determination in three natural water samples with passable results.