Standardization of Isotope Ratio Measurements for Doping Control
R M. Verkouteren
Pharmaceutical steroids are known to differ in isotopic composition from those produced naturally in the body. By measuring the 13 C/12C ratio of specific steroids deteched in urine, the technique of Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry (GCC-IRMS) can distinguish between exogenous and natural steroids. As a result, the technique has been designated a definitive test for steroid abuse by the World Anti-Doping Association (WADA) and the United States Anti-Doping Agency (USADA), and accepted as evidence in adjudication cases by the International Olympic Committee (IOC). While individual laboratories have successfully applied GCC-IRMS for isotopic measurements of steroids, little is actually known regarding the reproducibility of these measurements across laboratories since standard practices and reliable reference materials do not exist on which to base an assessment. The IOC and USDA have articulated the need to establish a harmonized international network of laboratories, with each laboratory proven to be equivalent in analytical performance. Measurements from such a network of laboratories, with each laboratory proven to be equivalent in analytical performance. Measurements from such a network would provide sound and globally equitable data needed to support and strengthen decisions made by IOC officials and foster confidence in those decisions.This paper will outline briefly some of the metrology issues that should be addressed in order to establish equivalence of analytical results across a laboratory network, discuss the lessons learned from prior exercises of isotopic measurement coordination, and offer some recommendations specific to this GCC-IRMS application.
Second Annual USADA Symposium on Anti-Doping Science
August 21-24, 2003
Proceedings of the Second Annual USADA Symposium on Anti-Doping Science
carbon, doping, gas chromatography, harmonization, intercomparison, isotope, mass spectrometry, standards, steroids