Carbon isotope ratios of nandrolone, boldenone, and testosterone preparations seized in Norway compared to those of endogenously produced steroids in a Nordic reference population

Isotope ratio mass spectrometry (IRMS) has been established in doping control analysis to identify the endogenous or exogenous origin of a variety of steroidal analytes including the 19-norsteroid metabolite norandrosterone (NorA). NorA can be found naturally in human urine in trace amounts due to endogenous demethylation or in situ microbial degradation. The administration of nortestosterone (nandrolone) or different prohormones results in the excretion of urinary NorA. Usually, this can be detected by IRMS due to differing δ C values of synthetic 19-norsteroids compared to endogenous reference compounds. The consumption of uncastrated pig edible parts like offal or even meat may also lead to a urinary excretion of NorA. In order to determine the δ C values of such a scenario, urine samples collected after consumption of a wild-boar-testicle meal were analyzed. IRMS revealed highly enriched δ C values for urinary NorA, which could be related to the completely corn-based nutrition of the animal. Isotopic analysis of the boar's bristles demonstrated a dietary change from C -based forage, probably in winter and spring, to a C -based diet in the last weeks to months prior to death. These results supported the interpretation of an atypical test result of a Central European athlete's doping control sample with δ C values for NorA of -18 ‰, most probably caused by the consumption of a wild boar ragout. As stated before, athletes should be fully aware of the risk that consumption of wild boar may result in atypical or even adverse analytical findings in sports drug testing.

Section: Introductionmentioning

confidence: 99%

Case Study: Atypical δ¹³C values of urinary norandrosterone

Hülsemann

Gougoulidis

Schertel

et al. 2018

“…Nevertheless, this detection strategy implies a significant difference of the δ 13 C VPDB values of synthetic testosterone preparations compared to endogenous marker steroids. In recent years, several research groups have reported the occurrence of testosterone products on the market displaying δ 13 C VPDB values within a range reported for endogenous urinary steroids . If such preparations are applied among athletes, the use of the IRMS technique is made more difficult.…”

Section: Introductionmentioning

confidence: 99%

Detection of testosterone esters in blood

Forsdahl

Erceg

Geisendorfer

et al. 2015

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.

“…14 As GC-C-IRMS analysis involves combustion of a target substance to form CO 2 no spectral information is available to facilitate analyte identification and help identify interfering peaks. 12 The availability of synthetic T and N preparations with endogenous δ 13 C values on the market, as has been shown in this study and those of others, [17][18][19]22 further complicates substantiating evidence of their misuse. 20 This step is also important to monitor co-elution of interferents with the target steroids which, if present, may alter the measured carbon isotope value.…”

Section: Gc-c-irms Analysismentioning

confidence: 50%

“…10,19 All δ 13 C values for steroids reported in this manuscript are for the free steroid, with correction for the influence of the acetate moiety done using a mass balance approach. [17][18][19]22 In doping-control analysis, detecting the misuse of steroids produced naturally by humans (i.e. 10 Splitting of GC eluents into the MSD and IRMS alleviates this problem by allowing simultaneous acquisition of full scan mass spectra of chromatographic peaks along with isotope ratio analysis.…”

Section: Gc-c-irms Analysismentioning

confidence: 99%

IRMS delta values (¹³C) of nandrolone and testosterone products available in the UK: Implications for anti‐doping

Brailsford

Majidin

Wojek³

et al. 2018

Anabolic androgenic steroids (AAS) are the most widely abused class of drugs by athletes and thus represent a significant problem to the anti-doping community.Confirmation of a doping violation for AAS cannot always be based on their presence alone due to the endogenous production of some steroids. Both testosterone (and its metabolites) and the major diagnostic metabolite of nandrolone (19-norandrosterone) are produced endogenously. Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) is used in such cases to differentiate between the administration of a synthetic preparation and endogenous steroid production by measurement of their differing carbon isotope ( 13 C/ 12 C) ratio. The purpose of this study was to investigate the availability of steroid preparations in the UK with a 13 C content analytically indistinguishable from that of endogenous steroids. Fourteen preparations containing nandrolone (n = 9) and testosterone (n = 5) were analyzed.The δ 13 C values were determined using GC-C-IRMS and the identity of the steroid preparations was confirmed using gas chromatography-mass spectrometry (GC-MS). Ten steroid preparations displayed δ 13 C values within the range expected for synthetic steroids (less than −27‰). However, four nandrolone preparations displayed δ 13 C values that overlap with the values considered to be endogenous in origin (range: −26 to −16‰). Misuse of these preparations could prevent the confirmation of nandrolone administration using GC-C-IRMS in anti-doping cases.