Abstract

Flunisolide and Triamcinolone acetonide belong to the glucocorticosteroid class. All glucocorticosteroids are prohibited in competition and included in the WADA Prohibited List in the section S9. The two glucocorticosteroids have the same molecular mass (434), same molecular formula (C24H31FO6) and similar chemical structures; they differ only by the position of the fluorine atom on the steroid skeleton – 6α for Flunisolide, respectively, 9 α for Triamcinolone acetonide. Therefore, the two prohibited substances may have common ions or MRM transitions and close chromatographic retention times, therefore interfering in each others detection. In the case of the analyze of a doping control sample containing one of these two substances, these interferences may result in a false negative analytical finding or in a misidentification of the substance detected. This paper presents the results of the tests carried-out by the liquid chromatography coupled with tandem mass spectrometry with triple quadrupole in order to differentiate the two prohibited substances. Einleitung (geändert)