High-temperature liquid chromatography-isotope ratio mass spectrometry methodology for carbon isotope ratio determination of anabolic steroids in urine.

Background: Gas Chromatography Isotope Ratio Mass Spectrometry (GC-C-IRMS) has long been used in routine laboratories to determine the δC values of anabolic steroids in urine, differentiating between, e.g., endogenous and synthetic testosterone (T) in sports doping control.

Validation of an ultra-sensitive detection method for steroid esters in plasma for doping analysis using positive chemical ionization GC-MS/MS.

The standard approach to detect misuse with testosterone in sport is based on the determination and evaluation of the urinary steroid profile followed by the confirmation of atypical profiles using isotope ratio mass spectrometry. The detection capacity of these methods can be attenuated by confounding factors or testosterone preparations with endogenous isotopic fingerprints. An alternative detection method for misuse of an endogenous steroid in sports is the direct detection of the administered steroid ester present in most preparations.