1. Certification of steroid carbon isotope ratios in a freeze-dried human urine reference material.
- Author
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Munton E, Liu FH, John Murby E, and Brynn Hibbert D
- Subjects
- Androsterone analogs & derivatives, Androsterone urine, Australia, Biomarkers urine, Biotransformation, Calibration, Chromatography, High Pressure Liquid, Etiocholanolone urine, Humans, Hydrolysis, Predictive Value of Tests, Pregnanediol urine, Quality Control, Reference Standards, Reproducibility of Results, Solvents chemistry, Substance Abuse Detection methods, Uncertainty, Anabolic Agents urine, Carbon Isotopes urine, Certification standards, Doping in Sports, Freeze Drying standards, Gas Chromatography-Mass Spectrometry standards, Performance-Enhancing Substances urine, Substance Abuse Detection standards, Testosterone urine
- Abstract
An accurate method for the measurement of carbon isotope ratios of steroids in human urine has been developed at the National Measurement Institute, Australia (NMIA) for the certification of a freeze-dried human urine reference material (CRM NMIA MX005). The method measures δ(13)C values by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) analysis following hydrolysis, solvent extraction and high performance liquid chromatography (HPLC) purification. Reference δ(13)C values for testosterone metabolites etiocholanolone, androsterone, and endogenous reference compounds (ERCs) 11β-hydroxyandrosterone and pregnanediol were determined, as well as information δ(13)C values for testosterone, epitestosterone, 11-oxoetiocholanolone, and a range of differences (Δ(13)C) between testosterone metabolites and ERCs. The measurement uncertainty was rigorously evaluated with expanded uncertainties for the reference δ(13)C values between 1.1 and 1.6 ‰ at the 95% coverage level., (Copyright © 2012 John Wiley & Sons, Ltd.)
- Published
- 2012
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