Markers of mesterolone abuse in sulfate fraction for doping control in human urine

The search for metabolites with longer detection times remains an important task in, for example, toxicology and doping control. The impact of these long-term metabolites is highlighted by the high number of positive cases after reanalysis of samples that were stored for several years, e.g. samples of previous Olympic Games. A substantial number of previously alleged negative samples have now been declared positive due to the detection of various long-term steroid metabolites the existence of which was unknown during the Olympic Games of 2008 and 2012.In this work, the metabolism of oxymesterone and mesterolone, two anabolic androgenic steroids (AAS), was investigated by application of a selected reaction monitoring gas chromatography-chemical ionization-triple quadrupole mass spectrometry (GC-CI-MS/MS) protocol for metabolite detection and identification. Correlations between AAS structure and GC-CI-MS/MS fragmentation behaviour enabled the search for previously unknown but expected AAS metabolites by selection of theoretical transitions for expected metabolites. Use of different hydrolysis protocols allowed for evaluation of the detection window of both phase I and phase II metabolites.For oxymesterone, a new metabolite, 18-nor-17β-hydroxymethyl-17α-methyl-4-hydroxy-androst-4,13-diene-3-one, was identified. It was detectable up to 46 days by using GC-CI-MS/MS, whereas with a traditional screening (detection of metabolite 17-epioxymesterone with electron ionization GC-MS/MS) oxymesterone administration was only detectable for 3.5 days.A new metabolite was also found for mesterolone. It was identified as 1α-methyl-5α-androstan-3,6,16-triol-17-one and its sulfate form after hydrolysis with Helix pomatia resulted in a prolonged detection time (up to 15 days) for mesterolone abuse.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Identification and characterization of novel long‐term metabolites of oxymesterone and mesterolone in human urine by application of selected reaction monitoring GC‐CI‐MS/MS

Polet

Gansbeke

Geldof

et al. 2017

“…A recent study illustrated that the sulfate form of this long‐term metabolite extended the detection time even further . Numerous other publications also highlighted the importance of sulfated AAS for long‐term detection …”

Section: Introductionmentioning

confidence: 96%

Gas chromatography−mass spectrometry analysis of non‐hydrolyzed sulfated steroids by degradation product formation

Polet

Gansbeke

Albertsdóttir

et al. 2019

Steroid detection and identification remain key issues in toxicology, drug testing, medical diagnostics, food safety control, and doping control. In this study, we evaluate the capabilities and usefulness of analyzing non‐hydrolyzed sulfated steroids with gas chromatography−mass spectrometry (GC–MS) instead of the conventionally applied liquid chromatography−mass spectrometry (LC–MS) approach. Sulfates of 31 steroids were synthesized and their MS and chromatographic behavior studied by chemical ionization−GC−triple quadrupole MS (CI−GC‐TQMS) and low energy−electron ionization−GC−quadrupole time‐of‐flight−MS (LE−EI−GC−QTOF−MS). The collected data shows that the sulfate group is cleaved off in the injection port of the GC–MS, forming two isomers. In CI, the dominant species (ie, [MH – H2SO4]+ or [MH – H4S2O8]+ for bis‐sulfates) is very abundant due to the limited amount of fragmentation, making it an ideal precursor ion for MS/MS. In LE−EI, [M – H2SO4].+ and/or [M – H2SO4 – CH3].+ are the dominant species in most cases. Based on the common GC–MS behavior of non‐hydrolyzed sulfated steroids, two applications were evaluated and compared with the conventionally applied LC–MS approach; (a) discovery of (new) sulfated steroid metabolites of mesterolone and (b) expanding anabolic androgenic steroid abuse detection windows. GC–MS and LC–MS analysis of non‐hydrolyzed sulfated steroids offered comparable sensitivities, superseding these of GC–MS after hydrolysis. For non‐hydrolyzed sulfated steroids, GC–MS offers a higher structural elucidating power and a more straightforward inclusion in screening methods than LC–MS.

“…18,19,[25][26][27] Therefore, unlike glucuronides, there is no universal method for the cleavage of all steroid sulfates and this is an important limitation of the indirect analysis of these conjugates by gas chromatography coupled to mass spectrometry (GC-MS). 13,14,[20][21][22][23][24][28][29][30][31][32][33][34][35] However, the LC-MS reported methods for endogenous sulfates are only focused on some of the possible sulfate metabolites (eg, sulfates of T, E, A, and Etio), and do not cover other metabolites that could be of interest. 27 As a result, in recent years, some methods have been described to directly analyze sulfate metabolites in urine using LC-MS systems.…”

Section: Introductionmentioning

confidence: 99%

Direct quantitation of endogenous steroid sulfates in human urine by liquid chromatography‐electrospray tandem mass spectrometry

Esquivel

Alechaga²,

Monfort³

et al. 2018

A method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the direct quantitation of endogenous steroid sulfates has been developed to be able to evaluate these metabolites as biomarkers to detect the misuse of endogenous androgenic anabolic steroids in sports. For sample preparation, a mixed-mode solid-phase extraction was optimized to eliminate the glucuronide fraction in the washing step thus obtaining only the sulfate fraction. Chromatographic separation was optimized to achieve adequate resolution between isomers. The electrospray ionization and the product ion mass spectra of the sulfates were studied in order to obtain the most specific and selective transitions. The method was validated for quantitative purposes for 11 steroid sulfates obtaining satisfactory values for linearity, accuracy, and intra- and inter-day precision (relative standard deviation better than 16.2%). Limits of quantitation ranged between 0.5 and 2 ng/mL. Extraction recoveries for sulfate metabolites were between 90 and 94%. Matrix effect ranged from 90 to 110% showing the absence of significant ion suppression/enhancement. Samples were found to be stable after 2 freeze/thaw cycles. The applicability of the method was checked by the analysis of 75 urine samples from healthy volunteers (54 males, 37 Caucasian and 17 Asian, and 21 Caucasian females) to evaluate the concentration levels of endogenous sulfate metabolites in basal conditions.