THE DETERMINATION OF CATECHOLS IN THE PRESENCE OF ASCORBIC-ACID AND URIC-ACID BY FLOW-INJECTION ANALYSIS EMPLOYING A POTENTIOMETRIC DIBENZO-18-CROWN-6 ELECTRODE DETECTOR

A polished platinum disc was modified by electropolymerization of dibe nzo-18-crown-6 (DB-18-C-6) onto the surface. This DB-18-C-6 electrode has been used as a detector for catechol and catecholamines in a poten tiometric-flow injection mode. The potentiometric-flow injection respo nse of the DB-18-C-6 modified electrode exhibited a linear response fo r catechol and catecholamine concentrations from 10(-2)-10(-6) M achie ving detection limits as low as 0.5 x 10(-6) M. An interference study was carried out with ascorbic acid and uric acid which are serious int erferents using amperometric detectors. No significant interference wa s observed for the presence of either of these two or mixture of these two common interferents until they were in greater than a 10-fold exc ess.