Carbon isotope ratios of endogenous steroids in Belgian Blue and Holstein cattle: Method development, reference population studies and application to steroid misuse control

Abstract

This first comprehensive investigation on the CIRs of endogenous urinary steroids demonstrated once more the potential of isotope ratios in aiding discrimination between endogenously produced and exogenously administered steroids. By means of the reference population-derived CIRs, it is possible to apply cattle-specific thresholds to differentiate between treated and non-treated animals.

Epiandrosterone sulfate prolongs the detectability of testosterone, 4‐androstenedione, and dihydrotestosterone misuse by means of carbon isotope ratio mass spectrometry

“…The CIR determinations for the T‐GEL and the EPIA excretion study were carried out using conditions described elsewhere …”

“…[15] T. Piper, H. Geyer, W. Schänzer. Degradation of urine samples and its influence on the 13 C/ 12 C ratios of excreted steroids. Drug Test Analysis.…”

“…The CIR determinations for the T-GEL and the EPIA excretion study were carried out using conditions described elsewhere. [5,13] The MDGC-IRMS setup followed a published configuration with some modifications. [9] In the first dimension, an OPTIMA 1 column (length 30 m, i.d.…”

“…[2,3] Endogenous steroids reflect the isotopic composition of the individual´s diet, whereas exogenous steroids commonly exhibit more depleted CIR, i.e. pharmaceutical preparations contain a lower 13 C content. CIR are expressed as δ 13 C-values against the international standard Vienna Pee Dee Belemnite (VPDB) following equation (1) and given in ‰ or mUr: [4]…”

Epiandrosterone sulfate prolongs the detectability of testosterone, 4‐androstenedione, and dihydrotestosterone misuse by means of carbon isotope ratio mass spectrometry

“…The CIR determinations for the T‐GEL and the EPIA excretion study were carried out using conditions described elsewhere …”

“…[15] T. Piper, H. Geyer, W. Schänzer. Degradation of urine samples and its influence on the 13 C/ 12 C ratios of excreted steroids. Drug Test Analysis.…”

“…The CIR determinations for the T-GEL and the EPIA excretion study were carried out using conditions described elsewhere. [5,13] The MDGC-IRMS setup followed a published configuration with some modifications. [9] In the first dimension, an OPTIMA 1 column (length 30 m, i.d.…”

“…[2,3] Endogenous steroids reflect the isotopic composition of the individual´s diet, whereas exogenous steroids commonly exhibit more depleted CIR, i.e. pharmaceutical preparations contain a lower 13 C content. CIR are expressed as δ 13 C-values against the international standard Vienna Pee Dee Belemnite (VPDB) following equation (1) and given in ‰ or mUr: [4]…”

Advances in steroid purification for novel techniques in carbon isotope ratio mass spectrometry of doping control

“…81 Traditional one-dimensional liquid chromatography (1D-LC) oen struggles to achieve sufficient resolution when separating structurally similar steroids and their metabolites with close polarity, which limit its ability to meet the demands of highly sensitive and selective analysis. 75,79,80,82,83 Semi-preparative two- dimensional liquid chromatography (2D-LC) and multidimensional liquid chromatography (MD-LC) have emerged as powerful tools for steroid purication, signicantly enhancing peak capacity and resolution by integrating orthogonal separation mechanisms. 74,[76][77][78][84][85][86][87][88] The core principle of 2D-LC is the use of two chromatographic columns with different separation mechanisms, such as a combination of reversed-phase chromatography with hydrophilic interaction chromatography (HILIC) or ion exchange chromatography (IEC).…”

Epiandrosterone sulfate prolongs the detectability of testosterone, 4‐androstenedione, and dihydrotestosterone misuse by means of carbon isotope ratio mass spectrometry

“…The CIR determinations for the T‐GEL and the EPIA excretion study were carried out using conditions described elsewhere …”

“…[15] T. Piper, H. Geyer, W. Schänzer. Degradation of urine samples and its influence on the 13 C/ 12 C ratios of excreted steroids. Drug Test Analysis.…”

“…The CIR determinations for the T-GEL and the EPIA excretion study were carried out using conditions described elsewhere. [5,13] The MDGC-IRMS setup followed a published configuration with some modifications. [9] In the first dimension, an OPTIMA 1 column (length 30 m, i.d.…”

“…[2,3] Endogenous steroids reflect the isotopic composition of the individual´s diet, whereas exogenous steroids commonly exhibit more depleted CIR, i.e. pharmaceutical preparations contain a lower 13 C content. CIR are expressed as δ 13 C-values against the international standard Vienna Pee Dee Belemnite (VPDB) following equation (1) and given in ‰ or mUr: [4]…”

Advances in steroid purification for novel techniques in carbon isotope ratio mass spectrometry of doping control

“…81 Traditional one-dimensional liquid chromatography (1D-LC) oen struggles to achieve sufficient resolution when separating structurally similar steroids and their metabolites with close polarity, which limit its ability to meet the demands of highly sensitive and selective analysis. 75,79,80,82,83 Semi-preparative two- dimensional liquid chromatography (2D-LC) and multidimensional liquid chromatography (MD-LC) have emerged as powerful tools for steroid purication, signicantly enhancing peak capacity and resolution by integrating orthogonal separation mechanisms. 74,[76][77][78][84][85][86][87][88] The core principle of 2D-LC is the use of two chromatographic columns with different separation mechanisms, such as a combination of reversed-phase chromatography with hydrophilic interaction chromatography (HILIC) or ion exchange chromatography (IEC).…”

Epiandrosterone sulfate prolongs the detectability of testosterone, 4‐androstenedione, and dihydrotestosterone misuse by means of carbon isotope ratio mass spectrometry

“…The CIR determinations for the T‐GEL and the EPIA excretion study were carried out using conditions described elsewhere …”

“…[15] T. Piper, H. Geyer, W. Schänzer. Degradation of urine samples and its influence on the 13 C/ 12 C ratios of excreted steroids. Drug Test Analysis.…”

“…The CIR determinations for the T-GEL and the EPIA excretion study were carried out using conditions described elsewhere. [5,13] The MDGC-IRMS setup followed a published configuration with some modifications. [9] In the first dimension, an OPTIMA 1 column (length 30 m, i.d.…”

“…[2,3] Endogenous steroids reflect the isotopic composition of the individual´s diet, whereas exogenous steroids commonly exhibit more depleted CIR, i.e. pharmaceutical preparations contain a lower 13 C content. CIR are expressed as δ 13 C-values against the international standard Vienna Pee Dee Belemnite (VPDB) following equation (1) and given in ‰ or mUr: [4]…”

Advances in steroid purification for novel techniques in carbon isotope ratio mass spectrometry of doping control

“…81 Traditional one-dimensional liquid chromatography (1D-LC) oen struggles to achieve sufficient resolution when separating structurally similar steroids and their metabolites with close polarity, which limit its ability to meet the demands of highly sensitive and selective analysis. 75,79,80,82,83 Semi-preparative two- dimensional liquid chromatography (2D-LC) and multidimensional liquid chromatography (MD-LC) have emerged as powerful tools for steroid purication, signicantly enhancing peak capacity and resolution by integrating orthogonal separation mechanisms. 74,[76][77][78][84][85][86][87][88] The core principle of 2D-LC is the use of two chromatographic columns with different separation mechanisms, such as a combination of reversed-phase chromatography with hydrophilic interaction chromatography (HILIC) or ion exchange chromatography (IEC).…”