Search

In the present paper, the electrochemical reduction of nitrite at a hemoglobin modified pencil lead electrode (Hb/PLE) is described. The electrochemical properties of nitrite were studied by cyclic voltammetry and chronoamperometry. Results showed that the hemoglobin film has an excellent electrochemical activity towards the reduction of nitrite. By using voltammetric and chronoamperometric methods, α, n α and n were calculated. Then the ability of the electrode for nitrite determination was investigated using differential pulse voltammetry. The electrocatalytic reduction peak currents were found to be linear with the nitrite concentration in the range from 10 to 220 µM with a detection limit of 5 µM. The relative standard deviation is 2 % for 3 successive determinations of a 100 µM nitrite solution. This modified electrode was successfully used for the detection of low amounts of NO2− in spinach sample and a spiked sample of tap water. [ABSTRACT FROM AUTHOR]

In the present paper simultaneous determination of nitrite and hydrogen peroxide using hemoglobin modified pencil lead electrode (Hb/PLE) prepared by a simple and rapid electroless method was described. In the first part of the work the reduction of NO2 and H2O2 at the modified electrode was investigated by cyclic voltammetry. Then under optimal conditions using differential pulse voltammetry, the biosensor could be used for the determination of H2O2 at concentration ranging from 5 to 240 M and NO2 at concentration ranging from 10 to 240 M. The detection limits were 3×10−6 and 5×10−6 M, for NO2 and H2O2 respectively. Differential pulse voltammetry also used for the simultaneous determination of NO2 and H2O2. This modified electrode successfully used for the determination of NO2 and H2O2 in tap water and mother's milk samples. [ABSTRACT FROM AUTHOR]