Flow injection amperometric determination of hydrazine at a cupric-neocuproine complex/anionic surfactant modified disposable electrode

Abstract

Hydrazine (N2H4) is a hazardous chemical widely used as rocket propellant and industrial intermediate, therefore its sensitive and accurate analysis in environmental samples is very important. In this study, a new approach for flow injection amperometric detection of N2H4 is proposed based on its electrocatalytic oxidation at a bis(neocuproine)copper (II) chelate complex/sodium dodecyl sulfate-modified graphite pencil electrode (Cu (II)-Ncp/SDS/GPE). The proposed electrode was prepared by consecutive adsorption of anionic surfactant (SDS) and Cu(II)-Ncp onto pencil leads and the surface morphologies of electrodes prepared were elucidated by recording of their SEM images. Cyclic voltammograms (CVs) showed that Cu(II)-Ncp exhibited an excellent redox mediator property for the electrocatalytic oxidation of N2H4, because oxidation potential of N2H4 at bare GPE shifted to more negative direction with the use of Cu(II)-Ncp/SDS/GPE. Then, flow injection (FI) electroanalysis of N2H4 was performed by utilizing the electrocatalytic oxidation of N2H4 at Cu(II)-Ncp/SDS/GPE. A wide linear range (0.25-250 mu M) with a limit of detection (LOD) of 0.07 mu M and a sensitivity of 262 mu AmM(-1)cm(-2) were obtained for the FI amperometric detection of N2H4. Satisfactory recoveries were obtained for N2H4 detection in water samples, showing that this method can be accurately applied to real water samples.