Elucidation of urinary metabolites of fluoxymesterone by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry.
The suitability of liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography mass spectrometry (GC-MS) for the elucidation of fluoxymesterone metabolism has been evaluated. Electrospray ionization (ESI) and collision induced dissociation (CID) fragmentation in LC-MS/MS and electron impact spectra (EI) in GC-MS have been studied for fluoxymesterone and two commercially available metabolites. MS(n) experiments and accurate mass measurements performed by an ion-trap analyser and a QTOF instrument respectively have been used for the elucidation of the fragmentation pathway. The neutral loss scan of 20 Da (loss of HF) in LC-MS/MS has been applied for the selective detection of fluoxymesterone metabolites. In a positive fluoxymesterone doping control sample, 9 different analytes have been detected including the parent compound. Seven of these metabolites were also confirmed by GC-MS including 5 previously unreported metabolites. On the basis of the ionization, the CID fragmentation, the accurate mass of the product ions and the EI spectra of these analytes, a tentative elucidation as well as a proposal for the metabolic pathway of fluoxymesterone has been suggested. The presence of these compounds has also been confirmed by the analysis of five other positive fluoxymesterone urine samples.
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B-9052 Zwijnaarde, Belgium. oscar.pozomendoza@ugent.be
Oscar J
OJ
Pozo
Wim
W
Van Thuyne
Koen
K
Deventer
Peter
P
Van Eenoo
Frans T
FT
Delbeke
D045930:Anabolic Agents / Q000737:chemistry / Q000378:metabolism / Q000652:urine; D002853:Chromatography, Liquid / Q000379:methods; D004300:Doping in Sports; D005474:Fluoxymesterone / Q000378:metabolism / Q000592:standards / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D053858:Metabolic Networks and Pathways; D015394:Molecular Structure; D012015:Reference Standards; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D015813:Substance Abuse Detection / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D045930:Anabolic Agents; D005474:Fluoxymesterone