Determination of hydrazine by polyNi(II) complex modified electrodes with a wide linear calibration range

Polymeric [Ni(11)(teta)](2+) (poly(Ni); teta =C-meso-(5,5,7,12,12,14-hexamethyl-1,4,8,11-tetra-azacyclotetradecane)) modified glassy carbon and Nafion (NO-coated glassy carbon electrodes (GC/poly(Ni) and GC/Nf/poly(Ni), respectively) were used for the efficient electrocatalytic oxidation of hydrazine (HZ) in 0.1 M NaOH. The catalytic currents were proportional to the concentration of HZ with a wide linear calibration range (LCR). GC/poly(Ni) had a LCR from 1.0 mu M to 10.0 mM, whereas that of GC/Nf/poly(Ni) ranged from 1.0 mu M to 100.0 mM. The latter is the widest LCR reported to date. The presence of the Nf film (i.e., in GC/Nf/poly(Ni)) not only increased the stability of the poly(Ni) film but also widened the LCR. The electrocatalytic oxidation of HZ obeyed first-order kinetics with respect to HZ concentration. The kinetic parameters were investigated by cyclic voltammetry and chronoamperometry. (C) 2011 Elsevier Ltd. All rights reserved.