Stable isotope ratio profiling of testosterone preparations
Adam Cawley1, Michael Collins, Rymantas Kazlauskas
1Australian Forensic Drug Laboratory, National Measurement Institute, 1 Suakin St., Pymble, Sydney 2073, Australia. adam.cawley@measurement.gov.au
Drug Testing and Analysis
|October 23, 2010
Summary
Analysis of black market testosterone revealed 9% of samples had carbon isotope ratios (δ(13)C) mimicking natural levels, potentially evading detection. Stable hydrogen isotope analysis (δ(2)H) offers a complementary method for identifying illicit testosterone use.
Area of Science:
- Analytical Chemistry
- Forensic Science
- Biochemistry
Background:
- Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) is standard for detecting exogenous testosterone.
- Synthetic testosterone is typically (13)C-depleted, distinguishing it from endogenous testosterone.
- Concerns exist regarding (13)C-enriched synthetic testosterone that could bypass current doping tests.
Purpose of the Study:
- To analyze the carbon isotope ratio (δ(13)C) of illicitly manufactured testosterone from border seizures.
- To investigate the potential of stable hydrogen isotope ratio (δ(2)H) analysis as a complementary detection method.
Main Methods:
- Analysis of 266 seized testosterone samples (2006-2009) using GC-C-IRMS for δ(13)C values.
- Development of gas chromatography-thermal conversion-isotope ratio mass spectrometry (GC-TC-IRMS) for δ(2)H analysis.
Main Results:
- A δ(13)C range of -22.9‰ to -32.6‰ was observed in seized samples.
- 9% (24/266) of samples exhibited δ(13)C values within the endogenous range (≥ -25.8‰).
- A δ(2)H range of -177‰ to -268‰ was determined for 173 samples.
Conclusions:
- Illicit testosterone production can yield products with δ(13)C values similar to endogenous steroids, posing a detection challenge.
- δ(13)C profiling of testosterone preparations aids in identifying specific illicit products for targeted testing.
- Stable hydrogen isotope ratio analysis (δ(2)H) can complement δ(13)C analysis for more robust detection of exogenous testosterone.
