Abstract: A method of gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of nine sex hormone residues, such as hexestrol, diethylstilbestrol, dienestrol, etiocholan-3α-ol-17-one, epitestosterone, estrone, estradiol, ethinylestradiol and estriol, in animal tissues was developed. The sex hormones were extracted with acetonitrile, then cleaned-up with a C18 solid-phase extraction (SPE) column. The microwave-assisted derivatization of the target components with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and trimethylchlorosilane (TMCS) (99:1, v/v) using pyridine as solvent was performed, and then the derivatives were analyzed by GC-MS. The limits of detection were 0.1~1 μg/kg for all hormones, and the limits of quantification were 0.2~2 μg/kg. The average recoveries of sex hormones were 68.8%~93.1%. The relative standard deviations (RSDs) of inter- and intra-assay were 4.1%~22.3% and 3.1%~17.9%, respectively. The real sample tests showed this method can be used for the sensitive and accurate determination of multi-sex hormones residues in biological samples.

Key words: animal tissues , hormones, microwave-assisted derivatization, multi-residue determination, solid-phase extraction (SPE), veterinary drugs, gas chromatography-mass spectrometry (GC-MS)