Natural-derived steroids and their analogues are present in various plants and insects. To minimize the chance of missing a positive doping test and avoiding potentially serious health problems, adequate screening methods are necessary for the detection of a wide range of natural-derived steroids and their analogues in dietary supplements. In this study, an accurate and simple liquid-chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine and quantify the natural-derived steroids and their analogues according to the International Conference on Harmonization of technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. The validation results indicating excellent extraction efficiency and low matrix effects show that the LC-MS/MS method is reliable for the detection of natural-derived steroids and their analogues. In addition, we established the ion fragmentation of turkesterone and ion fragmentation of four natural-derived steroids and their analogues. The validated method was applied to 60 dietary supplements purchased online and in person from international vendors in 2020. Ecdysterone and 5α-hydroxylaxogenin were detected respectively in 3 and 14 of 60 dietary supplements. Especially, a high amount of 5α-hydroxylaxogenin, an FDA-unapproved ingredient, was detected in two of dietary supplements (44.4 and 32.3 mg/g). This component should be controlled since it may cause unexpected side effects if administered excessively. Thus, this method will be helpful for the continuous control and supervision of unlicensed dietary supplements containing natural-derived steroids and their analogues.
Keywords: LC-MS/MS; anabolic steroids; dietary supplements; ecdysterone and 5α-hydroxylaxogenin; regulations; veterinary drug residues.