Fabrication of nanostructure electrochemical sensor for simultaneous determination of sulfite and nitrite in real samples

Since nitrite and sulfite have been extensively used and coexist in the ecosystem, resulting in threatening human health and disquieting pollution to the environment, the development of a selective and sensitive method for simultaneous determination of nitrite and sulfite is highly desirable for analytical application [1,2]. In this work, we describe a high sensitive electrochemical sensor for determination of sulfite with present of nitrite using a carbon paste electrode (CPE) modified by NiO nano particles (NiO -NPs) and acetylferrocene (AF). The AF/NiO-NPs/CPE showed good electro-catalytic activity for analysis of sulfite in the range of 5.0 nM-500.0 μM with limit of detection 1.0 nM using differential pulse voltammetric method (DPV). Figure 1 insert show differential pulse voltammograms of sulfite in the presence of nitrite with different concentration of two pollutants. The AF/NiO-NPs/CPE showed two separated oxidation signals with ΔE~310 mV in the solution containing sulfite and nitrite that is sufficient for simulations determination of these pollutants. The present method was successfully applied to the determination of sulfite and nitrite in water samples.