Determination of the Origin of 19-Norandrosterone in Urine by Gas Chromatography–Isotope-Ratio Mass Spectrometry for Doping Control

Abstract

The most difficult task in antidoping control is the identification of compounds whose origin can be either endogenous or exogenous. This paper presents a procedure for determining the origin of 19-norandrosterone based on the extraction of target components from urine, their multistage purification by semipreparative HPLC, acetylation, and quantification by gas chromatography–isotope-ratio mass spectrometry and gas chromatography–mass spectrometry. Effects of isotope fractionation were not observed in sample preparation. The degree of extraction of the target analytes was 80 ± 5%.