Electrooxidation of phenolic compounds causes severe fouling of electrode surface due to the formation of polymeric structures. In this contribution the effect of electrode pretreatment on the voltammetric signals of m-cresol and benzophenone-3 was studied at boron-doped diamond electrode.
The mechanical polishing by alumina and in-situ anodic activation at +2.4 V vs. Ag|AgCl, 3 mol.l-1 KCl) leads to well-developed voltammetric peaks in Britton-Robinson buffer pH 12.0 and 2.0, with the potential shift for m-cresol of ca 150 mV for the acidic and 450 mV for the base media to the more positive values for the latter activation method.
Obviously, the alumina-polished surface exhibits faster electron transfer kinetics for tested phenolic compounds, as for the redox couple [Fe(CN)6]3-/4-. For electroanalysis both approaches result in repeatable voltammetric signals and limits of detection in the 10-7 mol.l-1 concentration range.