Analytical methodology for assays of serum tryptophan metabolites in control subjects and newly abstinent alcoholics: preliminary investigation by liquid chromatography with amperometric detection.

A rapid, isocratic assay for the determination of all major tryptophan metabolites in serum samples from control non-alcoholic subjects, recovered alcoholics and newly abstinent alcoholics is described. The sample preparation involves only precipitation of protein with sulfosalicylic acid. The complete liquid chromatographic analysis is short (25 min) and the sensitivity of amperometric detection permits the routine assessment of catabolites at the picogram level. This preliminary longitudinal study of the basal and post-tryptophan load serum metabolites revealed a considerable scatter of experimental results for kynurenine and serotonin in all groups examined, probably owing to the clinical heterogeneity of the sample populations.