Studies on anabolic steroids

Detection of stanozolol and its metabolites in equine urine by liquid chromatography?electrospray ionization ion trap mass spectrometry

“…If it is allowed that the hydroxylation site is C16, there are four possible stereochemistries based on variation at C16 and C17. 16␣-Hydroxylation and 17-epimerization have both been reported for stanozolol in humans [1,3], while in the horse they have been variously reported for the analogous anabolic steroids methandrostenolone [15][16][17], 17␣-methyltestosterone [18], fluoxymesterone [19] and norethandrolone [20]. However, given that the accepted method of formation of 17-epimers from 17␣-alkyl-17␤-hydroxysteroids is via spontaneous hydrolysis of the tertiary 17␤-sulfate conjugate in the urine [15], their formation is obviously critically dependant on the phase II metabolism.…”

“…3 -Hydroxystanozolol, 4␣-hydroxystanozolol and 4␤-hydroxystanozolol were searched for but not detected. A preliminary search was also conducted for dihydroxylated metabolites, previously reported in humans [1][2][3], but these again were not detected.…”

“…The metabolism of stanozolol in humans has been investigated by a number of workers [1][2][3], mostly by electron ionization (EI) GC-MS analysis of pertrimethylsilylated urine extracts. Important metabolic pathways identified include hydroxylation at C3 , C4, C6 and C16, epimerization at C17 and combinations thereof (Fig.…”

Use of ion trap gas chromatography–multiple mass spectrometry for the detection and confirmation of 3′hydroxystanozolol at trace levels in urine for doping control

“…After addition of approximately 200 mg of solid carbonate buffer (Na 2 CO 3 -NaHCO 3 , 1:10), the sample was extracted with 5 ml TBME by shaking during 10 min. After centrifugation (2500 × g for 5 min), the organic phase was collected, dried with Na 2 SO 4 and the residue was derivatized with 50 l MSTFA-TMSI-DTE (1000:5:5, v/v/w) during 30 min at 60 • C. This method was initially optimized and validated by the Cologne anti-doping laboratory (Germany) several years ago and since, has been slightly modified and is commonly used by the anti-doping community for the extraction of anabolic steroids from urine [15,[37][38][39].…”

“…Currently, the most reliable, sensitive and specific analytical methods for anabolic steroids screening are GC-MS in SIM mode with electron impact (EI) ionization, GC-MS n and high resolution mass spectrometry (HRMS) [27][28][29][30][31][32][33][34]. Even if a few studies deal with the detection of stanozolol in hair [35][36], urine remains the favorite matrix for the analysis of this anabolic steroid and its metabolites [15,[37][38][39]. Regarding stanozolol, the IOC accredited laboratories mainly focus on two main metabolites, 3 hydroxystanozolol and 4␤-hydroxystanozolol, after enzymatic hydrolysis and TMS derivatisation of the urinary extract (Fig.…”