Simultaneous determination of femtomole quantities of 5-hydroxytryptophan, serotonin and 5-hydroxyindoleacetic acid in brain using HPLC with electrochemical detection.

A simple rapid method for the determination of 5-hydroxytryptophan, serotonin (5-hydroxytryptamine), and 5-hydroxyindoleacetic acid in brain is presented. Brain proteins are precipitated with Zn(OH)2. The indoles in the supernatant are separated by HPLC in less than than 8 min on a reverse phase column and detected electrochemically. As little as 38 fmol of hydroxyindole compound can be detected and quantitated. Because the method is rapid and uncomplicated many samples can be processed in a day.