Certification and Uncertainty Estimation of Certified Reference Materials for Steroids in Sports Drugs Testing

摘要

The 2005 World Anti-Doping Agency (WADA) statistics for athletes' samples that tested positive for steroids showed that testosterone and nandrolone accounted for 61percent and 16percent of all adverse analytical findings in this class of drugs, respectively. For effective doping control, WADA laboratories have highlighted the need for readily available certified reference materials. Certified reference materials play an important role in improving the accuracy, international comparability and validity of routine test results generated by end-user laboratories. The NMI is producing a suite of certified reference materials for the banned steroids, nandrolone and testosterone in both urine- and solution-based matrices. The materials were certified using high-accuracy isotope dilution mass spectrometry (IDMS). The use of primary method certified reference materials strengthens the metrological traceability of test results to the International System of Units (SI) and aids in best estimation of their associated measurement uncertainty. The uncertainties in the certified values of the materials were estimated using the ISO GUM and ISO Guide 35. Factors contributing to the uncertainty were identified from the IDMS measurement equation. Additional factors such as the method precision, material homogeneity and stability were also assessed. The expanded relative uncertainties ranged from 3percent to 8percent depending on the complexity of the measurement and the matrix.