Electrooxidation and voltammetric determination of hydrazine in aqueous media at the surface of glassy carbon electrode in the presence of chlorohydroquinone as a homogeneous electrochemical catalyst

According to environmental protection agency (EPA), hydrazine and its derivatives are known as environmental pollutants, and the hydrazine limit in sewage is set to be 1 ppm [1]. Hydrazine is absorbed through the skin, lungs, and gastrointestinal tract and is spread rapidly throughout the body. In the case of acute human toxicity, such as, multiple respiratory system infections, central nervous system, liver, lungs, brain, kidneys, DNA, as well as cancer, has been reported [2]. Therefore, its measurement was of great importance, but electrooxidation of hydrazine at the surface of carbon electrodes and most other common electrodes has a slower kinetics and requires high over potential. For this reason, in the recent years, much attention has been paid to the expansion of the use of catalysts for hydrazide electrooxidation [3,4]. In this work, electrochemical oxidation and voltammetric determination of hydrazine has been studied an the surface of glassy carbon electrode (GCE) in the presence of chlorohydroquinone as a homogeneous electrochemical catalyst in hydrazinum hydroxide aqueous solution. The electrochemical behavior of chlorohydroquinone was studied in aqueous media by using cyclic voltammetry method. The electrochemical oxidation of hydrazinum hydroxide in the presence of this mediator at GCE and the effect of various factors on the its electrocatalytic ability were investigated. The results show that the optimum pH value for electrocatalytic oxidation of hydrazinum hydroxide in the presence of chlorohydroquinone is pH=8.00. The electrocatalytic oxidation peak current of hydrazinum hydroxide in the presence of this mediator at GCE were linearly depended on its concentration in the range of 1.0×10-5 M – 2.0×10-2 M using cyclic voltammetry method. The detection limit (3σ) was determined as 6.040×10-6 M.