Selective Voltammetric Analysis of o-Diphenols from Olive Oil Using Na2MoO4 as Electrochemical Mediator

The complexing ability of molybdate vs. o-diphenols has been exploited for their selective electrochemical detection. Graphite screen printed and carbon paste electrodes have been evaluated as electrochemical transducers for the selective mediated detection of o-diphenol compounds in the presence of Na2MoO4. Immobilization of the mediator onto the electrode surface has also been achieved using different types of single and multiwall carbon nanotubes. The best sensor in terms of selectivity, sensitivity and stability was the Mo-MW-CNT-NH2 modified electrode. Using the mediator either in solution or immobilized, detection of o-diphenols with linearity in the ppm range was achieved. An amperometric flow injection analysis set-up was used to detect the o-diphenolic content of phenolic extracts obtained from olive oil samples.