title: Stable-labeled analogues and reliable quantification of nonprotein biomarkers by LC-MS/MS.
abstract: BACKGROUND
  The aim was to develop, and establish as suitable to begin assessment by full validation, a quantitative LC-MS/MS method for asparagine in human plasma. Therein, to utilize a stable-labeled analogue of asparagine to act as surrogate analyte, producing complete calibration curves and corresponding QC samples and another m/z distinct stable-labeled analogue to act as internal standard.
  
  
  RESULTS
  From two candidates, the surrogate analyte was selected through statistical comparisons of concentration-response data and the resultant method employed protein precipitation and LC on an unmodified silica column with multiple reaction monitoring detection mode. The calibration range was 50-10,000 ng/ml.
  
  
  CONCLUSIONS
  This method was successfully proven to meet the accuracy and precision acceptance criteria of current bioanalytical method validation guidelines.
authors.affiliation: Department of Bioanalysis, Huntingdon Life Sciences, Woolley Road, Alconbury, Huntingdon, Cambridgeshire, UK. macneilr@ukorg.huntingdon.com
authors.forename: Robert
authors.initials: R
authors.lastname: MacNeill
authors.forename: Timothy
authors.initials: T
authors.lastname: Sangster
authors.forename: Marc
authors.initials: M
authors.lastname: Moussallie
authors.forename: Vincent
authors.initials: V
authors.lastname: Trinh
authors.forename: Ryan
authors.initials: R
authors.lastname: Stromeyer
authors.forename: Erinne
authors.initials: E
authors.lastname: Daley
mesh_terms: D001216:Asparagine / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D009587:Nitrogen Isotopes / Q000097:blood*; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards
chemical_list: D015415:Biomarkers; D009587:Nitrogen Isotopes; D001216:Asparagine