title: Determination of salivary testosterone and androstendione by liquid chromatography-tandem mass spectrometry.
abstract: BACKGROUND
  Salivary steroid measurements have the potential to provide a non-invasive assessment of serum free steroid concentrations. Salivary testing has been proposed as a possible substitute for serum testing partly because of easy sample collection.
  
  
  METHODS
  We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous measurement of testosterone and androstendione in saliva. We spiked 100 μL of saliva with isotope-labeled internal standards and performed extraction with diethyl ether. After evaporation both steroids were analyzed by LC-MS/MS operating in the positive mode electrospray ionization (ESI) after separation on a reversed-phase column.
  
  
  RESULTS
  The calibration curves for analysis of testosterone and androstendione exhibited consistent linearity and reproducibility in the range of 20-1000 pmol/L. The limit of quantitation (LOQ) was 10 pmol/L for both steroids. The mean recovery of the analytes added to saliva ranged from 97 to 102%. Between-run CVs were 3.6-4.0% for testosterone and 4.8-8.0% for androstendione. The upper limit (the 97.5 percentile) of testosterone and androstendione reference ranges for males was 356 pmol/L and 344 pmol/L and that for females 39 pmol/L and 349 pmol/L, respectively.
  
  
  CONCLUSIONS
  This LC-MS/MS method has the required lower limit of quantification for analysis of salivary concentrations of testosterone and androstendione. The assay is rapid, reliable and simple to perform with a routine LC-MS/MS spectrometer with required sensitivity.
authors.affiliation: HUSLAB, Helsinki University Central Hospital, Finland. ursula.turpeinen@hus.fi
authors.forename: Ursula
authors.initials: U
authors.lastname: Turpeinen
authors.forename: Esa
authors.initials: E
authors.lastname: Hämäläinen
authors.forename: Mikko
authors.initials: M
authors.lastname: Haanpää
authors.forename: Leo
authors.initials: L
authors.lastname: Dunkel
mesh_terms: D000735:Androstenedione / Q000032:analysis*; D002853:Chromatography, Liquid; D005260:Female; D006801:Humans; D008297:Male; D012463:Saliva / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D013739:Testosterone / Q000032:analysis*
chemical_list: D013739:Testosterone; D000735:Androstenedione