Electrocatalytic Oxidation and Voltammetric Determination of Hydrazine by 1,1′-Ferrocenedicarboxylic Acid at Glassy Carbon Electrode

The homogeneous electrocatalysis of hydrazine oxidation by 1,1'-Ferrocenedicarboxylic acid (FDC) as a redox mediator was studied in aqueous medium at the surface of a glassy carbon electrode using cyclic voltammetry (CV), chronoamperometry and differential pulse voltammetry (DPV) methods. It was found that in the presence of FDC at pH 10.0, the catalytic oxidation peak current of hydrazine is high and the overpotential of hydrazine oxidation decreases about 250 mV. Based on the obtained results a mechanism for electrooxidation of hydrazine in the presence of FDC was proposed. The diffusion coefficient of hydrazine and the catalytic reaction rate constant were also determined using chronoamperometry. The experimental results showed that the mediated oxidation peak current of hydrazine is linearly dependent on the concentration of hydrazine in the ranges of 4.0 x 10(-5) M - 1.0 x 10(-3) M and 1.0 x 10(-5) M - 2.0 x 10(-4) M with CV and DPV methods, respectively. The detection limits (S/N = 3) were found to be 2.6 x 10(-5) M and 6.4 x 10(-6) M by CV and DPV methods, respectively. Finally, the proposed voltammetric method was used for the determination of hydrazine in water samples by the standard addition method.