Modification of Glassy Carbon Electrode by Polybromocresol using Cyclic Voltammetry as a Sensor and its Analytical Applications in Determination of Pyridoxine Hydrochloride in Commercial Drinks

Voltammetric behaviour of Pyridoxine hydrochloride (PHC) at bromocresol purple modified glassy carbon electrode (Poly BCP-GC) in phosphate buffers was used successfully for the analysis of PHC. Morphology of the electrode was characterised by atomic force microscopy. The effects of various parameters on the sensitivity of the method were investigated. Owing to the enhanced area and extraordinary characteristic surface of the electrode, the Poly BCP-modified glassy carbon electrode showed obvious electro-catalytic activity to the oxidation of PHC. The oxidation process was shown to be irreversible over the entire pH range studied (3.0-9.0) and was diffusion controlled. A possible electrooxidation mechanism was proposed. An intense peak was obtained with a pH value of 3.0, scan rate of 100mV/s, initial and final potential values were 0.4 V and 1.3 V. A sensitive linear voltammetric response for PHC was obtained in the concentration range of 2.0×10−8–8.0×10−8 M and 2.0×10−8–9.0×10−8 M with the detection limits of 6.28×10−9 M and 1.16×10−9 M for square wave voltammetric and differential pulse voltammetric techniques respectively. Analytical applications of this electrode have been studied for the determination of PHC in various pharmaceutical samples, commercial energy drinks and human blood serum. Due to its low detection limit, fast response, low cost and simplicity, this method proves to be advantageous over other methods.