ADSORPTIVE VOLTAMMETRIC BEHAVIOR OF THYMINE IN PRESENCE OF GUANINE AT THE STATIC MERCURY DROP ELECTRODE

An electrochemical stripping procedure for trace measurements of thymine is described by adsorption on a static mercury drop electrode. Cyclic voltammetry was used to characterize the interfacial and redox behavior. Optimum experimental conditions were found to be the use of a 0.005M NaOH solution, an initial potential of -0.08 V, a scan rate of 100 mV.s-1 and a linear scan mode. The response of free thymine is linear over the concentration range 0.1-0.5 ppm. Linear scan voltammetry, without acumulation time yields a detection limit of 62 ppb thymine. Acridine orange and copper were also investigated for measuring thymine in the presence of guanine.