Electrochemical Determination of Ascorbic Acid and Paracetamol in Pharmaceutical Formulations Using a Glassy Carbon Electrode Modified with Multi-Wall Carbon Nanotubes Dispersed in Polyhistidine.

PABLO R. DALMASSO, MARÍA L. PEDANO, GUSTAVO A. RIVAS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2012 vol. 173 p. 732 - 732

his work reports on the analytical performance of glassy carbon electrodes (GCE) modified with a dispersion of multi-wall carbon nanotubes (MWCNT) in polyhistidine (Polyhis) (GCE/MWCNT-Polyhis) for the simultaneous determination of ascorbic acid (AA) and paracetamol (PA). The modified electrode exhibited enhanced current responses and lower oxidation overvoltages, demonstrating excellent catalytic activities towards AA and PA oxidation compared to bare GCE. The linear dependence between the anodic peak currents and the square root of scan rates over the range of 0.005-0.300 V s−1 demonstrate that the electrooxidation of AA and PA occurs under diffusional control. The MWCNT-Polyhis modified GCE displayed a sensitivity of (3.8±0.1) x 104 uA M−1 (r = 0.998) and a detection limit of 0.76 M for the selective determination of AA in the presence of 1.00 x 10−4M PA. Conversely, for the direct quantification of PA in the presence of 5.00 x 10−4M AA, the sensitivity and