Sensitive high-performance liquid chromatography system with fluorometric detection of three urinary catecholamines in the same range.

A simple and highly sensitive HPLC method for the simultaneous determination of three catecholamines (norepinephrine, epinephrine, and dopamine) was developed. Catecholamines were separated on a reversed-phase column, reacted with ethylenediamine at 70 degrees C and pH 8.2 for 4 min, and fluorometrically determined. Those detection limits were in the same range of 20 to 40 pg. When the method was applied to human urine samples, 3,4-dihydroxyphenylalanine, their precursor, was also determined.