title: Detection of testosterone esters in blood.
abstract: Injections of synthetic esters of testosterone are among the most common forms of testosterone application. In doping control, the detection of an intact ester of testosterone in blood gives unequivocal proof of the administration of exogenous testosterone. The aim of the current project was to investigate the detection window for injected testosterone esters as a mixed substance preparation and as a single substance preparation in serum and plasma. Furthermore, the suitability of different types of blood collection devices was evaluated. Collection tubes with stabilizing additives, as well as non-stabilized serum separation tubes, were tested. A clinical study with six participants was carried out, comprising a single intramuscular injection of either 1000 mg testosterone undecanoate (Nebido(®)) or a mixture of 30 mg testosterone propionate, 60 mg testosterone phenylpropionate, 60 mg testosterone isocaproate, and 100 mg testosterone decanoate (Sustanon(®)). Blood was collected throughout a testing period of 60 days. The applied analytical method for blood analysis included liquid-liquid extraction and preparation of oxime derivatives, prior to TLX-sample clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS) detection. All investigated testosterone esters could be detected in post-administration blood samples. The detection time depended on the type of ester administered. Furthermore, results from the study show that measured blood concentrations of especially short-chained testosterone esters are influenced by the type of blood collection device applied. The testosterone ester detection window, however, was comparable.
authors.affiliation: Doping Control Laboratory, Seibersdorf Labor GmbH, Seibersdorf, Austria.|Natural Products and Medicinal Chemistry Research Group, Department of Pharmacy, University of Tromsø - The Arctic University of Norway, Tromsø, Norway.
authors.forename: Guro
authors.initials: G
authors.lastname: Forsdahl
authors.affiliation: Childrens Hospital Srebrnjak, Clinical Trials Unit, Zagreb, Croatia.|Josip Juraj Strostamyer University of Osijek, Medical School, Osijek, Croatia.
authors.forename: Damir
authors.initials: D
authors.lastname: Erceg
authors.affiliation: Doping Control Laboratory, Seibersdorf Labor GmbH, Seibersdorf, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Geisendorfer
authors.affiliation: Childrens Hospital Srebrnjak, Clinical Trials Unit, Zagreb, Croatia.|Josip Juraj Strostamyer University of Osijek, Medical School, Osijek, Croatia.
authors.forename: Mirjana
authors.initials: M
authors.lastname: Turkalj
authors.affiliation: Childrens Hospital Srebrnjak, Clinical Trials Unit, Zagreb, Croatia.|Josip Juraj Strostamyer University of Osijek, Medical School, Osijek, Croatia.
authors.forename: Davor
authors.initials: D
authors.lastname: Plavec
authors.affiliation: Institute of Biochemistry, Center for Preventive Doping Research, German Sport University, Cologne, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Thevis
authors.affiliation: Institute of Biochemistry, Center for Preventive Doping Research, German Sport University, Cologne, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Tretzel
authors.affiliation: Doping Control Laboratory, Seibersdorf Labor GmbH, Seibersdorf, Austria.
authors.forename: Günter
authors.initials: G
authors.lastname: Gmeiner
mesh_terms: D002853:Chromatography, Liquid; D004300:Doping in Sports; D004355:Drug Stability; D004952:Esters / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D006801:Humans; D007273:Injections, Intramuscular; D059625:Liquid-Liquid Extraction; D058573:Performance-Enhancing Substances / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods*; D053719:Tandem Mass Spectrometry; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood* / Q000493:pharmacokinetics
chemical_list: D004952:Esters; D058573:Performance-Enhancing Substances; D013739:Testosterone
keywords: LC-MS/MS; blood; detection time; doping; testosterone ester