title: HPLC-FLD determination of serum aromatic amino acids: application in chronic kidney disease patients.
abstract: BACKGROUND
  The aromatic amino acids (AAA) are very important amino acids in the body and have been suggested to be involved in many diseases. We describe the development and full validation of a high performance liquid chromatography with fluorescence detection (HPLC-FLD) method for simultaneously quantitative determination of serum AAA. Furthermore, we aimed to explore the clinical significances of AAA for chronic kidney disease (CKD).
  
  
  METHODS
  Serum samples were deproteinized by perchloric acid. Separation was carried out on a Megres C18 column (4.6 mm×250 mm i.d., 5 μm). The mobile phase consisted of 10% acetonitrile (v/v) in water and was run at a flow rate of 1.0 ml/min. The eluted AAA was monitored by measuring the fluorescence intensity using the programmed wavelength detection setting.
  
  
  RESULTS
  AAA determination in a serum sample was achieved in <10 min. The linear ranges of the method were 0.55-275 μmol/l, 3.05-1220.0 μmol/l and 0.049-49 μmol/l for Tyr, Phe and Trp, respectively. The limit of detection (LOD) was 0.014 μmol/l for Tyr, 0.5 μmol/l for Phe, and 0.0049 μmol/l for Trp. Recovery and reproducibility were satisfactory. Compared with healthy control subjects, the CKD patients showed lower serum levels of AAA. It should probably available to apply for screening and monitoring of CKD.
  
  
  CONCLUSIONS
  The method is simple, fast, accurate, and suitable for routine analysis.
authors.affiliation: Department of Clinical Laboratory, the Second Xiangya Hospital, Central South University, Changsha, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: Tang
authors.forename: Sa
authors.initials: S
authors.lastname: Mu
mesh_terms: D000293:Adolescent; D000328:Adult; D024322:Amino Acids, Aromatic / Q000097:blood*; D001774:Blood Chemical Analysis / Q000379:methods*; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000097:blood*; D057230:Limit of Detection; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
chemical_list: D024322:Amino Acids, Aromatic