title: More rapid and sensitive method for simultaneous determination of tryptophan and kynurenic acid by HPLC.
abstract: OBJECTIVE
  To describe a simple, rapid, and sensitive HPLC method for simultaneous determination of TRP and KYNA in human serum.
  
  
  METHODS
  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 micromol/L to 196 micromol/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 micromol/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.
  
  
  CONCLUSIONS
  The developed HPLC method is simple, convenient and can be applied in the diagnosis of related diseases.
authors.affiliation: Department of Clinical Laboratory, The Second Xiangya Hospital, Central South University, No.139, Renmingzhong Road, Changsha, Hunan 410011, China.
authors.forename: Lan-gan
authors.initials: LG
authors.lastname: Pi
authors.forename: Ai-guo
authors.initials: AG
authors.lastname: Tang
authors.forename: Xi-ming
authors.initials: XM
authors.lastname: Mo
authors.forename: Xi-bo
authors.initials: XB
authors.lastname: Luo
authors.forename: Xiang
authors.initials: X
authors.lastname: Ao
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000293:Adolescent; D000328:Adult; D044466:Asian People; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D005453:Fluorescence; D006262:Health; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007736:Kynurenic Acid / Q000097:blood*; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D012015:Reference Standards; D012044:Regression Analysis; D015203:Reproducibility of Results; D012212:Rheology; D012680:Sensitivity and Specificity; D013997:Time Factors; D014364:Tryptophan / Q000097:blood*; D055815:Young Adult; D019345:Zinc Acetate / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D014364:Tryptophan; D019345:Zinc Acetate; D007736:Kynurenic Acid; C032159:acetonitrile