Which advanced technique is mentioned as part of doping detection alongside urine and blood tests?

• A. Isotope ratio mass spectrometry
• B. Genetic sequencing
• C. Magnetic resonance imaging
• D. Chromatography

Answer: (A)

Focusing on identifying the origin of a detected substance is the key idea. In doping detection, urine and blood tests can reveal the presence of prohibited substances, but to determine whether a detected steroid came from external, synthetic sources rather than natural production, a more advanced technique is used: isotope ratio mass spectrometry. This method analyzes the ratios of stable carbon isotopes (such as carbon-12 and carbon-13) within the molecule. The isotope signature reflects the production pathway and feedstock used to make the substance; synthetic steroids often have a different carbon isotope pattern than those produced naturally in the body, so IRMS can confirm exogenous origin. That specialized capability is why this technique is highlighted alongside standard urine and blood testing.

Genetic sequencing isn’t used to identify doping substances, as it reads DNA rather than chemical compounds. Magnetic resonance imaging is an imaging tool for anatomy and physiology, not for chemical detection. Chromatography is a separation method commonly used in analytical workflows, but the distinctive, origin-detecting capability comes specifically from isotope ratio mass spectrometry.