Voltammetric determination of promethazine hydrochloride at a multi‐wall carbon nanotube modified glassy carbon electrode

Abstract

Abstract A simple and sensitive method is described for voltammetric determination of promethazine hydrochloride (PMZ), a widely used phenothiazine drug, based on its electrochemical oxidation at a multi‐wall carbon nanotube (MWCNT) modified glassy carbon electrode (GCE). Compared with bare GCE, the MWCNT‐modified GCE exhibited excellent enhancement effect on the electrochemical oxidation of PMZ. PMZ yielded two anodic peaks at about 0.61 V and 0.78 V, and the peak at 0.61 V was applied to the determination. Under optimized conditions, the anodic peak current was linear to the concentration of PMZ in the range from 5.0 × 10 −8 to 4.0 × 10 −4 M with the detection limit of 1.0 × 10 −8 M. The relative standard deviation (RSD) was 2.28% for 8.0 × 10 −6 M PMZ ( n = 10). To further validate its possible application, the proposed method was successfully used for the quantification of PMZ in pharmaceutical formulations and biological fluids with satisfactory results. Copyright © 2010 John Wiley & Sons, Ltd.