13C/12C Isotope ratio MS analysis of testosterone, in chemicals and pharmaceutical preparations

Torre, Xavier de la; González, J.; Pichini, Simona; Pascual, José A.; Segura, Jordi

doi:10.1016/s0731-7085(00)00452-0

Cited by 87 publications

(54 citation statements)

References 10 publications

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“…[13] As pharmaceutically produced anabolic steroids are not synthesized de novo but are derived from plant material, [14] they usually exhibit depleted δ 13 C values in comparison to the values found for endogenously produced steroids. [15] After application of an exogenous anabolic steroid the δ 13 C values of the steroid itself or of its metabolites exhibit depleted δ 13 C values while the endogenous reference compounds (ERCs) are not affected. ERCs are urinary steroids derived from metabolic pathways independent from anabolic steroids like the corticoid metabolite 11β-hydroxyandrosterone (OHA).…”

Section: Introductionmentioning

confidence: 99%

¹³C/¹²C Ratios of endogenous urinary steroids investigated for doping control purposes

Piper

Flenker

Mareck

et al. 2009

Drug Testing and Analysis

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In order to detect the misuse of endogenous anabolic steroids such as testosterone by athletes a total of n = 1734 suspicious urine samples were investigated by gas chromatography/combustion/isotope ratio mass spectrometry throughout the years 2005, 2006 and 2007. The 13 C/ 12 C ratio of a target substance (androsterone, a testosterone metabolite) was compared to the 13 C/ 12 C ratio of an endogenous reference compound (11β-hydroxyandrosterone). N = 1340 samples were investigated due to elevated testosterone/epitestosterone ratios, with n = 87 (6.5%) exceptional findings regarding their isotopic ratios. An additional n = 164 samples were investigated because of elevated dehydroepiandrosterone concentrations, with n = 2 (1.2%) exceptional findings. The remainder were subjected to isotope ratio analysis because of elevated androsterone levels or because this was requested by sports federations.Significant differences between female and male samples were found for the 13 C/ 12 C ratios of androsterone and 11β-hydroxyandrosterone but not for samples taken in or out of competition.A further n = 645 samples originating from other World Anti-Doping Agency accredited laboratories, mainly throughout Europe as well as South America, South Africa and Southeast Asia, were investigated. The 13 C/ 12 C ratios of the urinary steroids differ significantly for each geographical region, reflecting the dietary status of the individuals.The system stability over time has been tested by repeated injections of a standard solution and repeated processing of frozen stored blank urine. Despite a drift over time in absolute 13 C/ 12 C ratios, no significant change in the difference of 13 C/ 12 C (11β-hydroxyandrosterone) minus 13 C/ 12 C (androsterone) could be observed.

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Section: Introductionmentioning

confidence: 99%

¹³C/¹²C Ratios of endogenous urinary steroids investigated for doping control purposes

Piper

Flenker

Mareck

et al. 2009

Drug Testing and Analysis

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“…[26][27][28] In this study, the δ 13 C values of seized boldenone and nandrolone preparations were determined to decide if the steroids in the preparations were depleted in 13 C compared to what is seen for endogenously produced steroids in a Norwegian/Danish reference population. In addition, several testosterone preparations were analyzed.…”

mentioning

confidence: 99%

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

Hullstein

Sagredo

Hemmersbach

2014

Drug Testing and Analysis

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Determining the origin of anabolic androgenic steroids (AAS) that also are produced endogenously in the human body is a major issue in doping control. In some cases, the presence of nandrolone and boldenone metabolites might result from endogenous production. The GC-C-IRMS technique (gas chromatography-combustion-isotope ratio mass spectrometry) enables the carbon isotopic ratio (CIR) to be measured to determine the origin of these metabolites. The aim of this study was to use GC-C-IRMS to determine the δ(13) CVPDB values of seized boldenone and nandrolone preparations to decide if the steroids themselves were depleted in (13) C, compared to what is normally seen in endogenously produced steroids. In addition, several testosterone preparations were analyzed. A total of 69 seized preparations were analyzed. The nandrolone preparations showed δ(13) CVPDB values in the range of -31.5 ‰ to -26.7 ‰. The boldenone preparations showed δ(13) CVPDB values in the range of -32.0 ‰ to -27.8 ‰, and for comparison the testosterone preparations showed δ(13) CVPDB values of -31.0 ‰ to -24.2 ‰. The results showed that the values measured in the nandrolone and boldenone preparations were in the same range as those measured in the testosterone preparations. The study also included measurements of CIR of endogenously produced steroids in a Norwegian/Danish reference population. The δ(13) CVPDB values measured for the endogenous steroids in this population were in the range of -21.7 to -26.8. In general, most of the preparations investigated in this study show (13) C-depleted delta values compared to endogenously produced steroids reflecting a northern European diet.

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“…Since synthetic testosterone is often synthesized from sterols obtained from soybean (Glycine max), which is significantly depleted in 13 C, its consumption is detectable based on differences in values of δ( 13 C/ 12 C) of testosterone metabolites and metabolites of other endogenous steroidal hormones in urine [77]. Measurements of δ VPDB ( 13 C/ 12 C) made by de la Torre et al [78], in pharmaceuticals containing testosterone esters, had average −27.43 ‰ and standard deviation 76 ‰, while measurements in endogenous natural human testosterone and its main metabolites excreted into the urine in non-consumers of synthetic testosterone had δ VPDB ( The distributions of these random variables are determined using the Monte Carlo method, similarly to how it was applied in preceding examples. All of these distributions recognize and express the uncertainty of the atomic weights of the relevant isotopes, and the uncertainty of their amount fractions.…”

Section: Testosteronementioning

confidence: 99%

Interpreting and propagating the uncertainty of the standard atomic weights (IUPAC Technical Report)

Possolo

Veen

Meija

et al. 2018

Pure and Applied Chemistry

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Abstract:In 2009, the Commission on Isotopic Abundances and Atomic Weights (CIAAW) of the International Union of Pure and Applied Chemistry (IUPAC) introduced the interval notation to express the standard atomic weights of elements whose isotopic composition varies significantly in nature. However, it has become apparent that additional guidance would be helpful on how representative values should be derived from these intervals, and on how the associated uncertainty should be characterized and propagated to cognate quantities, such as relative molecular masses. The assignment of suitable probability distributions to the atomic weight intervals is consistent with the CIAAW's goal of emphasizing the variability of the atomic weight values in nature. These distributions, however, are not intended to reflect the natural variability of the abundances of the different isotopes in the earth's crust or in any other environment. Rather, they convey states of knowledge about the elemental composition of "normal" materials generally, or about specific classes of such materials. In the absence of detailed knowledge about the isotopic composition of a material, or when such details may safely be ignored, the probability distribution assigned to the standard atomic weight intervals may be taken as rectangular (or, uniform). This modeling choice is a reasonable and convenient default choice when a representative value of the atomic weight, and associated uncertainty, are needed in calculations involving atomic and relative molecular masses. When information about the provenance of the material, or other information about the isotopic composition needs to be taken into account, then this distribution may be non-uniform. We present several examples of how the probability distribution of an atomic weight or relative molecular mass may be characterized, and also how it may be used to evaluate the associated uncertainty.

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13C/12C Isotope ratio MS analysis of testosterone, in chemicals and pharmaceutical preparations

Cited by 87 publications

References 10 publications

¹³C/¹²C Ratios of endogenous urinary steroids investigated for doping control purposes

¹³C/¹²C Ratios of endogenous urinary steroids investigated for doping control purposes

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

Interpreting and propagating the uncertainty of the standard atomic weights (IUPAC Technical Report)

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13C/12C Isotope ratio MS analysis of testosterone, in chemicals and pharmaceutical preparations

Cited by 87 publications

References 10 publications

13C/12C Ratios of endogenous urinary steroids investigated for doping control purposes

13C/12C Ratios of endogenous urinary steroids investigated for doping control purposes

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

Interpreting and propagating the uncertainty of the standard atomic weights (IUPAC Technical Report)

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¹³C/¹²C Ratios of endogenous urinary steroids investigated for doping control purposes

¹³C/¹²C Ratios of endogenous urinary steroids investigated for doping control purposes