DETERMINATION OF TRYPTOPHAN AND KYNURENINE IN BRAIN MICRODIALYSIS SAMPLES BY CAPILLARY ELECTROPHORESIS WITH ELECTROCHEMICAL DETECTION

Capillary electrophoresis with electrochemical detection (CEEC) is eva luated for the determination of tryptophan and kynurenine in microdial ysis samples obtained from rat brain. These compounds were separated f rom all other electroactive metabolites of tryptophan. Limits of detec tion for both compounds were in the low attomole range. The response w as linear for kynurenine between 4.9 and 980 fmol injected with a corr elation coefficient of 0.9992 (n=12). The system was evaluated for mon itoring tryptophan and kynurenine in the extracellular fluid of the ra t brain following systemic administration of tryptophan.