Steroid profiling is one of the most versatile and informative screening tools for the detection of steroid abuse in sports drug testing. Concentrations and ratios of various endogenously produced steroidal hormones, their precursors and metabolites including testosterone (T), epitestosterone (E), dihydrotestosterone (DHT), androsterone (And), etiocholanolone (Etio), dehydroepiandrosterone (DHEA), 5a-androstane-3a,17b-diol (Adiol), and 5b-androstane-3a,17b-diol (Bdiol) as well as androstenedione, 6a-OH-androstenedione, 5b-androstane-3a,17a-diol (17-epi-Bdiol), 5a-androstane-3a,17a-diol (17-epi-Adiol), 3a,5-cyclo-5a-androstan-6ß-ol-17-one (3a,5-cyclo), 5a-androstanedione (Adion), and 5b-androstanedione (Bdion) add up to a steroid profile that is highly sensitive to applications of endogenous as well as synthetic anabolic steroids, masking agents, and bacterial activity. Hence, the knowledge of factors that do influence the steroid profile pattern is a central aspect, and pharmaceutical (application of endogenous steroids and various pharmaceutical preparations), technical (hydrolysis, derivatization, matrix), and biological (bacterial activities, enzyme side activities) issues are reviewed.
The application of a comprehensive gas chromatography/combustion/isotope ratio mass spectrometry-based method for the measurement of stable carbon isotopes of endogenous urinary steroids excreted as sulphates is presented. The key element in sample preparation is the consecutive cleanup with high-performance liquid chromatography of underivatized and acetylated steroids, which allows the isolation of seven analytes (pregn-5-ene-3β,17α,20α-triol, etiocholanolone, androsterone, epiandrosterone, dehydroepiandrosterone (DHEA), androst-5-ene-3β,17β-diol and androst-5-ene-3β,17α-diol) from a single urine specimen. These steroids are of particular importance to doping controls as they should enable the sensitive and retrospective detection of DHEA abuse by athletes.Depending on the biological background, the determination limit for all steroids ranges from 5 to 10 ng/mL for a 10 mL specimen. The method is validated by means of linear mixing models for each steroid, which covers the items, repeatability and reproducibility. The specificity was further demonstrated by gas chromatography/mass spectrometry for each analyte, and no influence of the sample preparation or the quantity of analyte on carbon isotope ratios was observed. In order to determine naturally occurring (13)C/(12)C ratios and urinary concentrations of all implemented steroids, a reference population of n = 67 subjects was measured to enable the calculation of reference limits for all relevant steroidal Δ values.The applicability of the developed method was tested by means of a DHEA excretion study. Despite the fact that orally ingested DHEA is preferentially converted into sulphated metabolites and that the renal clearance of sulphated steroids is slow, only the (13)C/(12)C ratio of EpiA demonstrated the potential to prolong the detection time for DHEA misuse.
Anabolic-androgenic steroids (AAS) represent one of the most frequently detected classes of prohibited substances in doping controls. Due to their long-lasting beneficial effects on athletic performance, utmost retrospectivity via urine analysis is desirable and accomplished by targeting long-term metabolites of the respective drugs. In case of stanozolol, a substantial variety of metabolites has enabled the identification of numerous adverse analytical findings in the past, and recent studies concerning complementary phase-I and phase-II metabolites has further expanded the windows of opportunity for detecting the abuse of stanozolol. In this study, the utility of liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry (LC-MS/MS) for the detection of 3'-OH-stanozolol glucuronide in sports drug testing is presented and the identification of two additional and so far unreported metabolites is shown. The structures of the complementary glucuronic acid conjugates were attributed to stanozolol-N-glucuronide and 17-epistanozolol-N-glucuronide. By means of chemical synthesis, stanozolol-N-glucuronide was prepared and used to corroborate the suggested structures. The 3'-OH-stanozolol glucuronide and the newly identified target compounds were implemented into routine sports drug test assays consisting of direct injection LC-MS/MS or solid-phase extraction (SPE) followed by LC-MS/MS. A considerably expanded detection window for stanozolol abuse was demonstrated compared to the use of conventional phase-I metabolites and methodologies based on, for example, low resolution LC-MS/MS or gas chromatography-tandem mass spectrometry (GC-MS/MS). The commercial availability of 3'-OH-stanozolol glucuronide has been of great value for confirmatory purposes, and 17-epistanozolol-N-glucuronide was found to be a favourable long-term metabolite for doping controls as it was observed up to 28 days post-administration of the drug. Applying the established methodology over a period of six months to 659 routine sports drug testing samples, a total of 85 adverse analytical findings was uncovered, 72 of which would have remained undetected using earlier employed GC-MS/MS approaches.
The discovery of the designer steroid tetrahydrogestrinone (THG) in elite athletes' doping control samples in 2003 demonstrated the availability of steroid derivatives prepared solely for doping purposes. Modern mass spectrometers utilizing electrospray ionization and collisionally activated dissociation (CAD) of analytes allow the structural characterization of steroids and their derivatization sites by the elucidation of fragmentation behaviors. A total of 21 steroids comprising either a 4,9,11-triene, a 3-keto-4-ene or a 3-keto-1-ene nucleus were investigated regarding their dissociation pathways, deuterated analogues were synthesized and fragmentation routes were postulated, permitting the identification of steroidal structures and modifications. Compounds based on a 4,9,11-triene steroid with an ethyl residue at C-13 (gestrinone analogues) generate abundant fragment ions at m/z 241 and 199, whereas the substitution of the C-13 ethyl group by a methyl residue (trenbolone analogues) results in a shift of m/z 241 to 227. Substances related to testosterone with a 3-keto-4-ene structure give rise to abundant fragment ions at m/z 109 and 97 whereas steroids with a 3-keto-1-ene nucleus eliminate the A-ring including the carbons C-1-C-4, in addition to C-19 that is proposed to migrate from C-10 to C-1 under CAD conditions.
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