Electrocatalytical properties of a potassium hexacyanoferrate (II) modified polypyrrole electrode. Application to vitamin C determination

An electrocatalytic detection on a potassium hexacyanoferrate (II) modified polypyrrole electrode has been studied. The pyrrole electropolymerization was carried out on a Pt disk of 3 mm diameter, using constant potential chr onoamperometry in the presence of the modifier. The electrochemical control of the electropolymerization and modification permit us to know the polyme risation charge, Q(p), as well as the number of moles of K4Fe (CN)(6) incor porated into the polymer at its generation step using Faraday's Law. Finall y a determination method for vitamin C (ascorbic acid) using scan and diffe rential pulse voltammetry was developed. This method was applied to determi nation of vitamin C in several samples, such as tablets and orange drinks, using the standard addition method.