More rapid and sensitive method for simultaneous determination of tryptophan and kynurenic acid by HPLC

Objective: To describe a simple, rapid, and sensitive HPLC method for Simultaneous determination of TRP and KYNA in human serum. Design and method: Samples were deproteinized by perchloric acid. KYNA was detected at 344 nm of excitation wavelength and 404 nm of emission wavelength, TRP was detected at 254 nm and 404 nm, with a total run time of 13 min per sample. Results: Standard curves of 0.49 mu mol/L to 196 mu mol/L of TRP were linear. Inter-day and intra-day coefficient of variations were 3.31% and 4.14%, respectively. Average recovery was 104.43%. Detection limit was 0.001 mu mol/L. The linearity of the assay was maintained from 1.5 nmol/L to 2093 nmol/L of KYNA. Inter-day and intra-day CVS were 3.20% and 4.27%, respectively. Average recovery was 101.19%. Detection limit was 0.05 nmol/L. Conclusion: The developed HPLC method is simple, convenient and can be applied in the diagnosis of related diseases. (C) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.