Determination of dopamine, norepinephrine, serotonin and their major metabolic products in rat brain by reverse-phase ion-pair high performance liquid chromatography with electrochemical detection.

A method is described for the separation and quantitation of catecholamines, serotonin, and their major metabolites with use of reverse-phase, ion-pair liquid chromatography with electrochemical detection. This method employs columns packed with a microparticulate C-18 resin, octyl sodium sulfate as the ion-pairing agent, and isocratic elution with a citrate-phosphate buffer containing methanol. Conditions are described for the separation of norepinephrine, normetanephrine, 3-methoxy-4-hydroxyphenylglycol, epinephrine, metanephrine, dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, serotonin, and 5-hydroxyindole-3-acetic acid and for their quantitation in extracts of rat brain tissue.