Cyclic Voltammetric Determination of Noradrenaline in Pharmaceuticals Using Poly(3-acetylthiophene)-Modified Glassy Carbon Electrode

A simple and reproducible method for determination of noradrenaline (NA) in pharmaceutical preparations using a poly(3-acetylthiophene)-modified glassy carbon electrode (p3-AT-GCE) was developed p3-AT-GCE, showed an excellent electrocatalytic effect on the oxidation of NA and accelerated its election transfer rate Compared with bare the modified electrode exhibited a remarkable shift of the oxidation potential of NA in the cathodic direction and a drastic enhancement of the anodic current response. The separation between anodic and cathodic peak potentials (Delta Ep) for NA in 0.1 mol L(-1) phosphate buffer solution (PBS) of pH 7.2 was 266 mV and 36 mV at bare and modified glassy carbon electrodes, respectively. However, the separation distance in 0.1 mol L(-1) PBS of pH 4.0 was only 29 mV p3-AT-GCE was used for determination of NA The peak current of NA increased linearly with its concentration in the range 2.5 x 10(-6)-10 x 10(-1) mol L(-1) Detection limit of NA In cyclic voltammetry was 6 6 x 10(-7) mol L(-1) Voltammetric responses of NA and ascorbic acid (AA) at p3-AT-GCE were separated Even 100-fold excess of AA with respect to NA did riot interfere with voltammetric determination of NA. The proposed method showed excellent stability and reproducibility