Simultaneous Determination of Catecholamine-Related Compounds by High Performance Liquid Chromatography with Postcolumn Chemical Oxidation Followed by a Fluorescence Reaction

Abstract

A simple separation method involving isocratic elution and a selective postcolumn derivatization method involving chemical oxidation followed by a fluorescence reaction are described regarding a simultaneous high performance liquid chromatographic determination of catecholamines (three species) and their precursor (one species) and metabolites (nine species, all in the free form). These compounds, isoproterenol and 3, 4-dihydroxyphenylpropanoic acid, are separated by ion-pair reversed-phase chromatography using a mixture of citrate buffer (pH 2.5) containing sodium octanesulfonate and methanol; they are then oxidized with periodate to the corresponding o-quinones, which are converted into fluorescent derivatives by reactions with meso 1, 2-diphenylethylenediamine. The detection limits (S/N=3, on column) vary from 15 to 570fmol, depending on the compounds.