Preparation of a polypyrrole electrode modified with nickel phthalocyaninecomplex to be used in a FIA system. Application to the propylgallate (PG) determination

A polypyrrole electrode modified with tetrasulfonate nickel (II) phthalocya nine complex (Pt/PPy/NiPcTs) was used as amperometric electrochemical detec tor in a flow system injection, in order to determine phenolic antioxidants in food. In previous investigations carried out in our laboratory, this el ectrode was used, as working electrode, by using cyclic voltammetry (CV), o btaining excellent results [1]. It was proved likewise that this electrode has an electrocatalytic effect in the oxidation of certain alimentary addit ives, like propylgallate (PG) [2]. In this last reference, a complete volta mmetry study of PG and an application of the proposed method to real sample s were done. In the present paper puts on to point all the necessary conditions to be ab le to use this electrode type in dynamic status, with a FIA system, using t he Taguchi experimental design to optimise the polymeric electrode and the electroanalytical response. The analytical application of is method consist s of the determination of propylgallate. On the other hand, the characteris tics of the mobile phase, as well as, the geometry of the circuit were opti mised, reproducibility studies were also made and, finally, the linear rela tionship between the signal and the concentration was verified. The propose d procedure is more precise, accurate and fast than the conventional voltam metry methods. These positive results offer new analytic possibilities to t his type of modified electrodes.