Abstract:

A gas chromatography/mass spectrometry (GC/MS) method was developed for the determination of multi-residues of steroid anabolic hormones epitestosterone (ETS), testosterone 17-propionate (PTS), nandrolone (17β-NT ), 17α-methyltestosterone (MTS), 17β-estradiol (17β-ES),estriol(EST), 17α-ethinylestradiol (EES), estrone (ESN) and 17β-estradiol 3-benzoate (BES) in the muscle tissues of various animal species. Homogenized tissue samples were enzymatically digested in acetate buffer (pH 5.0). Consequently, methanol was added and the mixtures were extracted under ultrasonication incubation. Clean-up was carried out for at least two times with methyl tert-butyl ether (MTBE) liquid-liquid partitioning followed by a reversed-phase solid phase extraction (SPE) cartridge purification. The eluate with methanol was evaporated to dryness by N2 at 40 ℃ and derivatization was achieved with N-methyl-N-(trimethylsilyl) trifluoroacetamide/iodotrimethylsilane/dithioerythritol （MSTFA-TMIS-DTE） at 60 ℃ for 45 min. The reaction mixture was injected into a gas chromatograph with a DB-1 capillary column coupled with a mass spectrometer . The samples were tested by different selected ion monitoring modes with electron impact （EI） source for the androgens and estrogens. The limits of quantitation (LOQ) for the above 9 hormones were in the range of 1.0-2.0 μg/kg. At the 2.0 μg/kg LOQ spiked level, the mean recoveries were within 62.5%-80.5%, and the relative standard deviations were within 12.5%-26.8%. The real sample tests showed this method can be used for the sensitive and accurate determination of multi-steroid anabolic hormones residues in biological muscle samples.

Key words: anabolic steroid hormones, gas chromatography/mass spectrometry (GC/MS), multi-residue analysis
, solid phase extraction