Determination of free and total catecholamines and salsolinol in urine by ion-pair reversed-phase liquid chromatography with electrochemical detection after a one-step sample clean-up

Simultaneous measurement of dopamine, serotonin, their metabolites and tryptophan in mouse brain homogenates by high-performance liquid chromatography with dual coulometric detection

“…To our knowledge, only one method has been described using coulometric detection (Saito et al, 1992). Most of these HPLC methods require extraction of the compounds from biological samples: dopamine is usually isolated by retention on alumina (Eisenhofer et al, 1986); 3-methoxytyramine (3-MT) and 5-HT is most frequently isolated by ion-exchange chromatography (Schleicher et al, 1983;Odink et al, 1986); the acidic metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) are generally extracted with ethyl acetate (Yoshida et al, 1982;Picard et al, 1985;Seegal et al, 1986). However, all these extraction procedures are time consuming and appeared to have drawbacks concerning the limited number of compounds that can be extracted, with imprecise or low recovery due to difficulties in sample preparation or with degradation of these compounds during extraction procedures.…”

Stress reactivity and its relationship to beef quality in Nguni steers supplemented with Acacia karroo leaves

“…The urine samples were first hydrolysed before the determination of catecholamines as described by Odink et al (1986). Urine samples were then loaded on cationic columns and the catecholamines were eluted with boric acid.…”

Interferences by anti-TB drugs in a validated HPLC assay for urinary catecholamines and their successful removal

“…Our method is based on the use of Bio-Rex 70, a cation-exchange resin [12]. The latter report [12] investigated the chromatographic behaviour of catecholamine metabolites and analogues on the cation exchange column. Acid metabolites were not retained by the resin and thus did not interfere with the assay [12].…”