Selective Determination of Dopamine in the Presence of Ascorbic Acid Using a Poly (Nicotinic Acid) Modified Carbon Paste Electrode

A carbon paste electrode (cpe) modified with poly (nicotinic acid) was used forthe sensitive and selective voltammetric determination of dopamine (da). theelectrochemical response characteristics of the modified electrode toward da, ascorbic acid(aa) were investigated by cyclic voltammetry (cv). the results show an efficient catalyticactivity of the electrode for the electro-oxidation of da, which leads to an improvement tothe reversibility of the electrode response. the effect of ph and potential sweep rate on themechanism of the electrode process was investigated. the modified electrode exhibits anefficient electron mediating behavior along with well-separated oxidation peaks for aa andda. under the optimum ph of 7.0 in 0.2 m phosphate buffer solution (pbs), the cv anodicpeak current showed a linear relation vs. da correlation coefficients. high sensitivity andselectivity, high reproducibility, along with ease of preparation and regeneration of theelectrode surface by simple polishing make this method suitable for the determination of daand aa in pharmaceutical and clinical preparations.