ELECTROCHEMICAL DETERMINATION OF ACETAMINOPHEN AT THE SURFACE OF A GLASSY CARBON ELECTRODE MODIFIED WITH MULTI-WALLED CARBON NANOTUBE

چکیده مقاله

A multi-walled carbon nanotubes (MWCNTs) film coated glassy carbon electrode (GCE) was fabricated, and the electrochemical behavior of acetaminophen (AAP) was studied in Britton–Robinson (BR) buffer (pH 7.0), using cyclic voltammetry (CV), square-wave voltammetry (SWV) and differential pulse voltammetry (DPV). Cyclic voltammograms of AAP showed enhanced redox responses for the MWCNT/GCE with respect to the bare GCE. The anodic peak potential shifted to less positive values by increasing the pH. The electrochemical oxidation of AAP at MWCNT/GCE was quasi-reversible and diffusion-controlled. Experimental parameters, such as pH, scan rate, SW frequency and step height, were optimized for AAP measurement. Under the optimum pH of 7.0 in 0.1 M BR buffer solution, the DPV anodic peak current showed a linear relation versus AAP concentration in the range of 7.9×10 -7 to 3.4×10 -4 M with a detection limit of 3.3×10-7 for DPV, and from 6.5×10 -7 to 3.5×10 -4 M for SWV with a detection limit of 2.1×10-7 (signal to noise = 3). Moreover, this method demonstrated good reproducibility (RSD = 1.3%, n = 10) and long-term stability. These have been applied to the determination of AAP in effervescent dosage samples.