Separation and Detection of Tryptophan Metabolites in Biological Samples
色氨酸及其主要代谢产物的分离和在生物样品中的测定

A reversed phase HPLC method for separation and determination of the major tryptophan (TRP)metabolites in both pyrrolas pathway and TRP hydroxylase pathway, including TRP, kynurenine(KN), 3hydroxykynurenine (3-HKN), kynurenic acid (KA), xanthurenic acid (XA), 5-hydroxytryptop ban (5-HTP ),5-hydroxytr yp tamin (5-HT ) and 5-hydroxyindoleacetic acid (5-HIAA ), has been de veloped by sequential optimization of mobile phase based on acetate buffer and methanol. Trichloroacetic acid(TCA) was used as ionpairing reagent to increase the retention of 3-HKN. The effects of pH and concentrations of TCA on separation were studied. Good separation can be achieved at pH 4. 0-5. 0 of mobile phase in less than 25 min. When TCA was not used, 3-HKN was hard to be detected in biological samples. The maximum retention of 3-HKN was obtained at pH 4. 0 with mobile phase containing 50 mmol/L TCA. Combination of electrochemical (ED) and ultraviolet (UV) detection was used in which ED was responsible for detection of 3-HKN , 5-HTP,5-HT and 5-HIAA and UV for the others. The innuences of potential of ED and wavelength of UV on detection were studied. The optimization of conditions for separation and detection in different biological samples was also discussed.