A simple and specific method for the analysis of 11 compounds (catecholamines, their precursors and their metabolites) has been developed using hydrophilic interaction chromatography. Adrenaline, noradrenalin, dopamine, serotonin, 3,4-dihydroxy-phenylalanine, 3-methoxytyramine, tryptophan, homovanillic acid, tyrosine, 3,4-dihydroxy-phenylacetic acid, 5-hydroxyindole-3-acetic acid and 3,4-dihydroxybenzylalanine (as internal standard) were separated on a TSK gel amide 80 column. The influence of parameters such as organic modifier type and content, salt nature and concentration, pH as well as column temperature on the selectivity were investigated. The optimized mobile phase consisted of a 20 mM ammonium acetate aqueous solution buffered at pH 3 and acetonitrile (20:80 v/v) mixture.
