title: Confirmation of no impact from different anticoagulant counter ions on bioanalytical method.
abstract: BACKGROUND
  In the past several years, the impact of changing counter ions while keeping the same anticoagulant in bioanalytical LC-MS/MS methods has become a highly discussed topic. In order to confirm that there is no impact from counter ions, matrix effect and stability evaluations were performed on bicalutamide LC-MS/MS bioanalytical methods.
  
  
  RESULTS
  Independently from the anticoagulant counter ion used, the matrix effect evaluation met acceptance criteria, even when using conditions expected to increase matrix effect, such as protein precipitation with an analog internal standard. Freeze-thaw along with storage stabilities, namely short- and long-term, demonstrated less than 8% deviation regardless of the counter ion used.
  
  
  CONCLUSIONS
  Differences in the anticoagulant counter ion used has no impact on the bicalutamide bioanalytical LC-MS/MS method.
authors.affiliation: Algorithme Pharma Inc., 575 Armand-Frappier, Laval, Quebec, H7V 4B3, Canada.
authors.forename: Annik
authors.initials: A
authors.lastname: Bergeron
authors.forename: Mélanie
authors.initials: M
authors.lastname: Bergeron
authors.forename: Fabio
authors.initials: F
authors.lastname: Garofolo
mesh_terms: D000813:Anilides / Q000097:blood* / Q000737:chemistry; D000925:Anticoagulants / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D004492:Edetic Acid / Q000097:blood / Q000737:chemistry; D006801:Humans; D007477:Ions / Q000737:chemistry; D009568:Nitrendipine / Q000097:blood / Q000737:chemistry; D009570:Nitriles / Q000097:blood* / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014105:Tosyl Compounds / Q000097:blood* / Q000737:chemistry
chemical_list: D000813:Anilides; D000925:Anticoagulants; D007477:Ions; D009570:Nitriles; D014105:Tosyl Compounds; D009568:Nitrendipine; D004492:Edetic Acid; C053541:bicalutamide