title: Determination of trimethylamine, trimethylamine N-oxide, and taurine in human plasma and urine by UHPLC-MS/MS technique.
abstract: BACKGROUND
  Trimethylamine-N-oxide (TMAO) is produced in the liver from trimethylamine (TMA) and is an important cellular osmolyte and potential atherogenic factor. Taurine is involved in cholesterol metabolism and also serves as a cellular osmolyte. Given their significant biological functions, the development of reliable measurement techniques is crucial to further study their role in health and disease METHODS: A new ultrahigh performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of TMA, TMAO, and taurine in plasma and urine. The method consisted of a deproteinization step using methanol/acetonitrile (15:85) that contained 0.2% formic acid and isotope-labeled internal standards. Samples were separated by centrifugation and injected into the UHPLC system. Quantification was conducted using a triple-quadrupole mass spectrometer detector with electrospray ionization interface in positive mode.
  
  
  RESULTS
  The limits of detection ranged from 0.08 to 0.12μmol/L. The calibration curves were linear (r≥0.999) over the range examined (0.15-400μmol/L) for all compounds. The inter- and intra-day coefficients of variations were≤14.5% for TMA and ≤8% for TMAO and taurine. TMAO and taurine were found to be stable in EDTA plasma for at least 14 months at -70°C. Mean recoveries ranged from 95% to 109% and the relative matrix effects were≤4.0%. The method was applied to study physiological and pre-analytical factors in plasma and urine samples.
  
  
  CONCLUSIONS
  The new UHPLC-MS/MS method has good accuracy, precision, and recovery. The assay combines simple sample processing with a short run time, making it well suited for high-throughput routine clinical or research purposes.
authors: Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine Building 57, D-66421, Homburg/Saar, Germany. Electronic address: s9huawwa@stud.uni-saarland.de.
authors: Hussain Mohamad
authors: HM
authors: Awwad
authors: Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine Building 57, D-66421, Homburg/Saar, Germany.
authors: Juergen
authors: J
authors: Geisel
authors: Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine Building 57, D-66421, Homburg/Saar, Germany; Aarhus Institute of Advanced Studies, University of Aarhus, Høegh-Guldbergs Gade 6B, Building 1632, Dk-8000, Aarhus C, Denmark. Electronic address: rima.obeid@uks.eu.
authors: Rima
authors: R
authors: Obeid
mesh_terms: D000368:Aged; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D008744:Methylamines / Q000097:blood* / Q000652:urine*; D008875:Middle Aged; D053719:Tandem Mass Spectrometry / Q000379:methods; D013654:Taurine / Q000097:blood* / Q000652:urine*
chemical_list: D008744:Methylamines; D013654:Taurine; C005855:trimethyloxamine; C023336:trimethylamine
keywords: Plasma; Pre-analytical; Stability; Taurine; Trimethylamine N-oxide; Urine