Electrocatalytic Oxidation and Ion Chromatography Detection of S_2O_3~(2-),SO_3~(2-),I~- and SCN~- at Glassy Carbon Electrode with Functionalized Multi-Wall Carbon Nanotubes Film

摘要

In this research,a glassy carbon electrode modified with the functionalized multi-wall carbon nanotubes (MWNT-COOHs) film was used as an amperometric sensor for the determination of S_2O_3~(2-),SO_3~(2-) ,I~- and SCN~-.The electrochemical behavior of those oxidizable inorganic anions at this modified electrode was studied by means of cyclic voltammetry (CV).The experimental results indicate that the modified electrode exhibits a high electrocatalytic activity towards the oxidation of those anions with a relatively high sensitivity,a good stability and a long-life.Separated by ion chromatography(IC) with 1.25 mmol/L H_2SO_4 as an eluent,those oxidizable anions can be determined by the MWNT-COOHs modified electrode successfully.Under the optimal chromatographic conditions,the detection limits are 1.5X10~(-7) mol/L for S_2O_3~(2-),2.5X 10~(-7) mol/L for SO_3~(2-) ,1.2 X 10~(-7) mol/L for I~- and 2.0 X 10~(-7) mol/L for SCN~- ,respectively.The method was applied successfully to the determination of those anions in environmental water.