Investigation of electrochemical behavior of hydrazine with alizarin as a mediator on glassy carbon electrode

The anodic oxidation of hydrazine has been studied on a glassy carbon electrode by electrocatalytic effect of alizarin as a homogenous mediator at 0.1 M concentration of phosphate buffer (pH= 6). Using linear sweep voltammetry study showed that, the catalytic current of this system depends on the concentration of hydrazine. The catalytic peak current obtained, was linearly dependent on the hydrazine concentration in the ranges of 10-800 M and the detection limit was 4.6 M by linear sweep voltammetry. The magnitude of the peak current for alizarin increased severely in the presence of hydrazine, and proportional to concentration of hydrazine. The diffusion coefficient of hydrazine was estimated using chronoamperometry. This method also were used for determine the catalytic rate constant at catalytic reaction between alizarin and hydrazine. The experimental results showed that the peak current varied in the presence of different metal cations, but these effects were omitted in the presence of EDTA, while almost all of anions had no effect on the peak current of hydrazine. The importance of the technique is its ability to electrocatalytic determination of hydrazine with alizarin as homogenous electrocatalyst, while it does not need to prepare as for modified electrode. The independency of this method from the interferences, and its ability at removing the effect of most cationic interferences easily are the features of the technique.