CONDUCTING PHENYLENEVINYLENE BLENDS AS ELECTRODE MATERIALS IN LC AMPEROMETRIC DETECTION

A novel amperometric electrode based on a conducting polymer is presen ted and its properties are compared with those of a glassy carbon elec trode. The electrode material was made by mixing 1,4-bis[2-(3,4,5-trim ethoxy-phenyl)ethenyl]benzene with iodine and polycarbonate. The blend was coated on a glassy carbon electrode by evaporation from a chlorof orm solution. Catecholamines were u(?s)ed as test substances in LC and FIA measurements. They were oxidized at a potential of +0.7 V (vs. SC E). The electrode exhibited a linear response for injected concentrati ons from 2.5 x 10(-6)M to 2.5 x 10(-3)M. It had a response time of 1.2 s and a coulometric efficiency of 0.74% at a linear flow rate of 1 mL /min. The electrode material is stable for several months under normal operating conditions. Hydrodynamic voltammograms showed E-1/2 values shifted by approximately 100 mV as compared to glassy carbon. The nove l redox-conducting coating is proposed as an alternative material for the development of enzyme electrodes and chemically modified electrode s.