Simultaneous Determination of Dopamine, Serotonin and Folic acid at Torasemide Modified Carbon Paste Electrode: A Cyclic Voltammetric Study

A carbon paste electrode modified by torasemide was used for determination of dopamine (DA). The modified electrode exhibited strong promoting effect and stability towards the electrochemical oxidation of dopamine at pH 7.0.in phosphate buffer solution (PBS). The parameters which influence the electrode response like paste composition; effects of scan rate, concentration, pH, surfactants and interferences have been studied. The linear range of DA 0.9990 and the detection limit for DA was found to be 2.4×10−6 M. Anionic surfactant Sodium Dodecyl Sulphate (SDS) showed very good electrocatalytic effect on the modified carbon paste electrode. The preparation of the modified electrode was easy and renewed by simple polishing gives very good reproducibility, high stability in its voltammetric response and low detection limit for DA.