Liquid chromatographic determination of urinary dopamine and norepinephrine as fluorescamine derivatives

Dopamine (DM) and norepinephrine (NE) with 3,4-dihydroxybenzylamine as internal standard in normal human urine were extracted with alumina, labeled with fluorescamine and determined fluorometrically by liquid chromatography. The method is simple and in the case of excretion of DM in urines of subjects receiving 1-dopa, even the alumina treatment was unnecessary. The C.V. of method was 4.3% and 4.5% for DM and NE, respectively. The mean contents of DM and NE in 7 normal urines were 182 and 35.5 ng/mg creatinine, respectively.