Determination of catecholamines and O-methylated metabolites by reversed-phase high-performance liquid chromatography with fluorimetric detection and its application to enzyme kinetics.

In a study of the enzymatic methylation of individual catecholamines, high-performance liquid chromatography was used for the separation from their O-methylated metabolites. A RP-8 column and an aqueous mobile phase containing dodecylsodium sulphonate were used, and the eluate was analysed fluorimetrically (the detection limit was 20 pg). Each catecholamine used and its O-methylated compounds could be detected individually without interference from the catechol-O-methyltransferase and S-adenosylmethionine present. The application of the method to the study of enzyme kinetics is described.