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

Metabolism of Anabolic Steroids and Their Relevance to Drug Detection in Horseracing

“…Despite this, the use of LC-MS for the detection of AASs in urine is becoming increasingly popular [39,41,58] and a number of multi-analyte methods have been published [87,88]. A significant issue with LC-MS is that the response of the steroids is very structure dependant [73,89].…”

“…The metabolism of stanozolol has also been studied using LC-MS in the electrospray ionization mode [41]. Following intramuscular injection of stanozolol, metabolites were isolated from urine using a two-stage solid-phase extraction procedure.…”

Modern Techniques for the Determination of Anabolic–Androgenic Steroid Doping in the Horse

“…In equine competition, this may include performance inhibitors as well as enhancers future science group testosterone [8,9], boldenone [10], methandienone [11][12][13], stanozolol [14,15], 17a-methyltestosterone [16][17][18][19], fluoxymesterone [20,21], norethandrolone [22], danazol [23], methenolone [24], turinabol [25], mesterolone [26], methandriol [27] and tetrahydrogestrinone [28]), and the various international AAS regulatory thresholds are also targeted at this matrix. The sample preparation required for the MS based ana lysis of AASs in equine urine is necessarily complex (FiguRe 2).…”

“…The relatively sparse functionalization of most AASs exhibit variable susceptibility to atmospheric pressure ionization, which makes the construction of a comprehensive LC-MS method difficult. At one end of the scale, electrospray ionization (ESI) provides excellent sensitivity for susceptible analytes, and LC-ESI-MS has long been a favored analytical technique for easily ionized steroids, such as stanozolol and its metabolites [15] and, to a lesser extent, for steroids with conjugated ketone groups such as D 4 -and D 1,4 -3-ketosteroids [38,40,[56][57][58]. Steroids featuring only hydroxyl groups and unconjugated ketones are largely inert to ESI, however, and, for these, alternative approaches must be sought.…”

Structure Characterization of Low Molecular Weight Target Analytes: Electrospray Ionization

“…Suggested dissociation pathways of (a) tetrahydrogestrinone, and (b) and (c) stanozolol 3,42,43. 4.5 , 17 ), represents one of the most frequently misused anabolic androgenic steroids with analytical peculiarities due to the presence of ESI product ion mass spectra of protonated molecules [M+H] + of (a) tetrahydrogestrinone (mol wt = 312), (b) methyltrienolone (mol wt = 284), and (c) stanozolol (mol wt = 328) recorded on a QTrap 2000 system.…”