Voltammetric Determination of Lidocaine Hydrochloride with Single-Wall Carbon Nanotubes Modified Electrode

To prepare single-wall carbon nanotubes modified glassy carbon electrode (designated abbreviately as SWCNT′s/GCE), a dispersion of SWCNT′s in 10 g·L-1 SDBS solution was added dropwise onto the surface of GCE, and dried by infrared radiation. Electrochemical property of the modified electrode was studied by cyclic voltammetry. It was found that a sensitive oxidation peak given by lidocaine hydrochloride was observed at SWCNT′s/GCE and that the magnitude of peak current was enhanced by 5 times as compared with the bare GCE. Based on these findings, a selective method for determination of lidocaine hydrochloride by cyclic voltammetry was proposed. Linear relationship between values of oxidation peak current and concentration of lidocaine hydrochloride was ranged from 0.9 to 50.0 μmol·L-1, with detection limit (3S/N) of 0.3 μmol·L-1. The proposed method was used in the determination of lidocaine hydrochloride in injection samples, giving results in consistency with the labeled values. Recovery of the method was tested by standard addition method, and values of recovery found were in the range of 98.0%-105%.