Determination of Thiopental in Aqueous Media Using Catechol Electrocatalytic Properties

In this paper، the electrochemical oxidation of catechol was studied in the presence of thiopental in phosphate buffer solution (0. 2 mol L-1، pH=6. 0) at the surface of glassy carbon electrode (GC) by cyclic voltammetry technique. The results showed that cathodic peak current of catechol reduced in the presence of various concentrations of thiopental and catechol can participate in a 1،4-Michael addition reaction with thiopental under an electrochemical – chemical (EC) mechanism. Then، the differential pulse voltammetry technique is used for determination of thiopental. The decreasing of the cathodic current of catechol showed a linear relationship with the thiopental concentration in the range of 5. 0×10-6- 125. 0×10-6mol L-1 and a detection limit of 2. 0×10-6mol L-1. The method was successfully applied for determination of thiopental in human serum samples.