Paediatric reference values for urinary catecholamine metabolites evaluated by high performance liquid chromatography...

The majority of the published reference range data on catecholamines excretion by healthy children is incomplete and often contradictory (1). We assayed in the urines of 127 healthy children the values of the catecholamines (norepinephrine, epinephrine, dopamine) and their methylated metabolites (normetanephrine, metanephrine, 3-methoxytyramine) for the determination of paediatric reference ranges. Data were expressed as micrograms/24 h, mumol/24 h and mmol/mol creatinine. An isocratic HPLC procedure by ion-pair reversed phase chromatography on a C18 column, using a single mobile phase containing formic acid, acetonitrile, diethylamine and octane sulphonic acid (ion pairing agent), permitted the separate assay of the various fractions of total catecholamines. The relations between each biogenic amine and age were studied and reference values were determined as a function of age.