Highly improved electrocatalytic behavior of sulfite at carbon ionic liquid electrode: application to the analysis of some real samples.
The electrocatalytic oxidation of sulfite was investigated at carbon ionic liquid electrode (CILE). This electrode is a very good alternative to previously described electrodes because the electrocatalytic effect is achieved without any electrode modification. Comparative experiments were carried out using carbon paste electrode (CPE) and glassy carbon electrode (GCE). At CILE, highly reproducible and well-defined cyclic voltammograms were obtained for sulfite with a peak potential of 0.55 V vs. Ag/AgCl. Sulfite oxidation at CILE does not result in deactivation of the electrode surface. The kinetic parameters for this irreversible heterogeneous electron transfer process were determined. Under optimal experimental conditions, the peak current response increased linearly with sulfite concentration over the range of 6-1000 microM. The detection limit of the method was 4 microM. The method was applied to the determination of sulfite in mineral water, grape juice and non-alcoholic beer samples.
Safavi
Afsaneh
A
Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 71454, Iran. safavi@chem.susc.ac.ir
Maleki
Norouz
N
Momeni
Safieh
S
Tajabadi
Fariba
F
D001628:Beverages; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013447:Sulfites / Q000032:analysis* / Q000737:chemistry*; D013997:Time Factors
D052578:Ionic Liquids; D013447:Sulfites; D002244:Carbon