Sensitive Electrochemical Detection of the Nitrite Ion Using an ISEM-3 Graphite Electrode and Comparison with Other Carbon-Containing Materials

The need for an accurate, rapid, and affordable method for determining nitrite ions arises from their toxic effects on humans at elevated levels in wastewater and drinking water. The electrochemical determination is faster, cheaper, and less labor-intensive. It is based on the study of the electrochemical oxidation of NO2− ions at different carbon electrodes. In this work, it was established that the cyclic voltammograms for the ISEM-3 graphite electrode have an excellent limit of detection for nitrite ions: 5 × 10−6 M at pH 3, which makes it possible to determine the NO2− content below the maximum permissible concentration (6.5 × 10−5 M) in water.