title: Determination of N-desmethyl- and N-bisdesmethyl metabolites of Sibutramine in doping control analysis using liquid chromatography-tandem mass spectrometry.
abstract: Since January 2006, the list of prohibited substances established by the World Anti-Doping Agency includes the antidepressant / anti-obesity drug Sibutramine. Due to its rapid degradation to its active metabolites N-desmethyl and N-bisdesmethyl Sibutramine, reference compounds were synthesized and included into an existing screening assay to allow the unambiguous determination of these metabolic products in human urine using liquid-liquid extraction followed by liquid chromatography/tandem mass spectrometry. Characteristic product ions, obtained after electrospray ionization and collision-induced dissociation, were elucidated using high resolution/high accuracy mass measurements with a hybrid linear ion trap/orbitrap mass analyzer. Based on diagnostic product ions, the extended screening procedure was validated for both Sibutramine metabolites using a triple quadrupole mass spectrometer. Items such as lower limits of detection (6-40 ng mL(-1)), recoveries (39-42%), intraday precision (low: 5.5-10.6%, medium: 4.9-5.9%), high: 12.8-16.4%) and interday precision (low: 15.0-22.8%, medium: 17.7-18.6%), high: 16.5-25.6%) were evaluated, and a clinical spot urine sample was analyzed to demonstrate the applicability of the developed assay in sports drug testing.
authors.affiliation: Institute of Biochemistry and Center for Preventive Doping Research, German Sport University Cologne, Carl-Diem Weg 6, 50933 Cologne, Germany. m.thevis@biochem.dshs-koeln-de
authors.forename: Mario
authors.initials: M
authors.lastname: Thevis
authors.forename: Gerd
authors.initials: G
authors.lastname: Sigmund
authors.forename: Anna-Katharina
authors.initials: AK
authors.lastname: Schiffer
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Schänzer
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D003503:Cyclobutanes / Q000032:analysis* / Q000378:metabolism* / Q000652:urine; D004300:Doping in Sports / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008875:Middle Aged; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D003503:Cyclobutanes; C058254:sibutramine