Determination of catecholamines in urine by ion-exchange liquid chromatography with electrochemical detection

A liquid chromatographic method for the determination of free urinary concentrations of epinephrine, norepinephrine and dopamine is presented. For urine samples, pre-purified by adsorption onto alumina, ion-exchange chromatography was, in terms of selectivity, found to be superior to the more widely used reversed-phase chromatography. The column eluates were monitored with an electrochemical detector utilizing a glassy carbon working electrode. The method allows determination of the concentrations in 0.5 ml of normal urine samples with a relative standard deviation below 2%.