Fluorescence reactions of fluorescamine with levodopa and its derivatives: Fluorescence assay of 3- methoxy-4- hydroxyphenylalanine in levodopa dosage forms

A simple fluorometric method for the quantitation of 3-methoxy-4-hydroxyphenylalanine, either alone or in the presence of levodopa, is presented. Fluorescence is developed by reaction with fluorescamine. The interactions of this reagent with levodopa and a number of its derivatives under various experimental conditions were studied. Negligible fluorescence was obtained with levodopa, dopamine, levodopa benzyl ester, and 6-hydroxydopamine.