Study of the urinary metabolites of 17ɑ-methyl-19-nortestosterone in human using gas chromatography – mass spectrometry. Preliminary results

17ɑ-methyl-19-nortestosterone (MNT), a steroid prohibited in sport, has been marketed since the 1990s, however their use is increasingly, mainly because it is contained in nutritional supplements. The study of the metabolism of the prohibited substances for athletes allows to identify new metabolites that could increase the veracity of the results. This work studied preliminary the in-vivo metabolism of MNT.The study was conducted after a single oral administration dose using the simple quadrupole mass spectrometry coupled to gas chromatography and considering the steroids classic metabolic reactions.Nine MNT metabolites were detected in urine. Mass spectra and fragmentation patterns were proposed for each metabolite. In addition to MNT, the detection of four metabolites corroborated what is described in the specialised literature. However, to our knowledge, four other metabolites have not been explicitly described. According to the time-course, three metabolites were still detected at 96-, 84- and 72-hours port-administration. These detection windows can increase by using other instrumentations such as a triple quadrupole mass spectrometer with multiple reaction monitoring acquisition mode.