Cost-effective analysis of sulfite using carbon nanotubes

Iranian researchers from Isfahan University of Technology, in association with researchers from Allameh Majlesi University, succeeded in the analysis of sulfite with the least possible cost and energy. Researchers used carbon nanotubes in this research, which provided higher selectivity and effective area of the electrode. Selective measurement of sulfite ion requires HPLC method, which in addition to the high price of the equipment, needs the use of expensive solutions that are harmful to the environment. Moreover, only skilled operators are able to work with the solutions. The use of voltammetirc and amperometric methods is easier and simpler than spectroscopy or HPLC methods. Dr. Ali Asqar Ensafi, member of the Scientific Board of Isfahan University of Technology, explained the objectives of the research, and said, “Sulfite analysis is one of the most difficult analyses in wet chemistry and spectroscopy methods, because other groups such as sulfide or thiosulfate react similar to sulfite and disturb the reaction. Therefore, we were looking for a selective method to analyze sulfite with the least possible distraction and by using the least amount of chemicals.” The presence of carbon nanotubes significantly helps the reduction of extra voltage of sulfite oxidation and as a result, it simplifies electron transfer on the electrode surface. Therefore, it improves the selectivity. The presence of carbon nanotubes on the surface also increases the effective area of the electrode. High selectivity and appropriate sensitivity (due to the presence of carbon nanotubes and modifiers) in sulfite analysis in real and water samples can be considered as the most important specifications of the research. Results of the research have been published in 2013 in International Journal of Environmental Analytical Chemistry, vol. 93, issue 6, pp. 650-660.