Synergetic effects in the flow injection analysis determination of catechol in the presence of excess ascorbic acid by series dual-band amperometric detection

Abstract The deviations at high concentrations (>10  −5  M) in the calibration curves for the determination of catechol in catechol/ascorbic acid mixtures by flow injection analysis using series dual-band poly(3-methylthiophene)-coated electrodes has been re-examined. The cyclic voltammetry (at pH≅7.4) of catechol/ascorbate and catechol/urate mixtures and NMR measurements show these deviations are the result of the simultaneous homogeneous catalytic reaction of dehydrocatechol with ascorbate.