Electrocatalytic determination of ascorbic acid on a glassy carbon electrode chemically modified with cobalt pentacyanonitrosylferrate.
An electrochemically prepared thin film of cobalt pentacyanonitrosylferrate (GC/CoPCNF) was used as a surface modifier for glassy carbon electrodes. The oxidation of ascorbic acid on a glassy carbon electrode modified with GC/CoPCNF as a working electrode was studied using cyclic voltammetry, rotating disk electrode (RDE) voltammetry and chronoamperometry in a 0.25 M KNO3 + 0.25 M phosphate buffer (pH 7) solution. The glassy carbon modified with CoPCNF showed good electrocatalytic activity toward ascorbic acid oxidation. The kinetics of the catalytic reaction was investigated, and the average value of the rate constant (k) for the catalytic reaction and the diffusion coefficient (D) were evaluated by different approaches for ascorbic acid, and were found to be 3.3 +/- 0.3 x 10(2) M(-1) s(-1) and 3.2 +/- 0.3 x 10(-6) cm2 s(-1), respectively.
Sabzi
Reza Emamali
RE
Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran. rezasabzi@yahoo.com
Pournaghi-Azar
Mohammad Hussein
MH
D000465:Algorithms; D001205:Ascorbic Acid / Q000032:analysis*; D002244:Carbon; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D007202:Indicators and Reagents; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry*
D007202:Indicators and Reagents; D009942:Organometallic Compounds; C510334:cobalt pentacyanonitrosylferrate; D002244:Carbon; D001205:Ascorbic Acid