Simultaneous determination of anabolic steroids and synthetic hormones in meat by freezing-lipid filtration, solid-phase extraction and gas chromatography–mass spectrometry

Estradiol, testosterone, progesterone, zeranol and diethylstilbestrol including estradiol metabolites were determined simultaneously in meat. Extraction of growth hormones was carried out by ultasonication using a methanol–water mixture. The growth hormones in the meat extract can be effectively separated from lipids by freezing-lipid filtration, followed by C8-solid phase extraction (SPE). During freezing-lipid filtration, about 90% of lipids are removed without any significant loss of growth hormones. For further clean-up, silica- and aminopropyl-SPE were used. To enhance detection sensitivity, the growth hormones are derivatized with trimethylsilyl reagents. Quantitation using isotope-labelled internal standards was performed by gas chromatography–mass spectrometry in the selected ion monitoring mode. The method detection limits were 0.1–0.4 μg/kg for all growth hormones. Overall recoveries of synthetic and natural growth hormones were 68–106% with coefficients of variation of 5–16% for the complete procedure.