Electrochemical oxidation of dopamine in the presence of secondary amine. An alternative way for quantitative dopamine determination at a gold electrode

Electrooxidation of dopamine, in the absence and presence of morpholine as a nucleophile was investigated on a gold electrode in phosphate buffer, pH 7. The results have shown that electrochemically produced dopaminoquinone undergoes an attack by morpholine via 1,4-Michael addition. The reaction products have been identified by electrospray ionization mass spectrometry (ESI-MS). The procedure used is suitable for quantitative dopamine determination in the presence of the ascorbic acid excess at a unmodified gold electrode.