Highly Sensitive and Selective Voltammetric Method for the Determination of Hydrazine at a Poly(Eriochrome Black T) Modified Pencil Graphite Electrode (p-EBT/PGE)

Abstract

This paper presents a simple, sensitive, selective, cost-effective indirect voltammetric method for determining hydrazine using a poly(Eriochrome black T) modified pencil graphite electrode (p-EBT-PGE). Alizarin Red S (ARS) was used as a mediator in acetic acid–acetate buffer (pH 5.5) and 0.2 M KCl. The difference between the mediator’s oxidation currents measured in hydrazine’s presence and absence served as the analytical response for voltammetrically determining hydrazine. The ARS–hydrazine system’s voltammetric properties at the p-EBT-PGE were also investigated. The limit of detection and two analytical ranges of the method were estimated to be 0.87 nM and 2.9 to 10.0 nM and 3.0 to 60.0 μM. The method has the best limit of detection among reported voltammetric methods. The recoveries in tap water, wastewater, and drinking water samples were between 99.60% and 104.74%, while the relative standard deviations were between 1.6 and 4.2. Uncertainty calculations were also evaluated for hydrazine-spiked samples by following a top–down approach.