Simultaneous determination of catecholamines and metanephrines in urine by HPLC with fluorometric detection

A method is described for quantitative analysis of urinary free and conjugated catecholamines and metanephrines. The compounds are isolated from the urine by cation exchange on Amberlite CG 50. Separation is performed by ion-pair reversed-phase high-performance liquid chromatography. For detection of the amines their native fluorescence emitted at 313 nm on excitation at 285 nm was monitored. There was good separation of the compounds of interest, while interference by exogenous compounds other than the catecholamines or metanephrines was minimal. The method is rapid and precise, and it has a broad linear working range for all six DOPA metabolites, making it suitable for clinical analysis. Reference values for children of 0-16 years were established. Examples are shown of excretion patterns of DOPA metabolites from patients with different types of neurogenic tumour.