Real time characterization of catalysis by on-line electrochemistry mass spectrometry. Investigation of quinone electrocatalysis of amine oxidation

Electrochemistry (EC) on-line with mass spectrometry (MS), with a particle beam (PB) liquid interface (EC/PB/MS), has been successfully applied to the investigation of the electrocatalytic type reaction, the oxidation of an amine, dimethylaminopyridine, by a quinone, dopamine. The investigation, of the reaction pathway, by EC/PB/MS supports catalytic type oxidation of the amine via formation of an intermediate quinone-amine adduct. EC/PB/MS allowed verification of the reaction pathway, through the identification of the intermediate, and the products of the oxidation, in close to real time, by EC/MS on-line. Oxidation of the adduct has been estimated as the limiting kinetic step in the reaction.