[Determination of 41 hormones in cereal feeds by liquid chromatography-tandem mass spectrometry]

A method was developed for the determination of 10 androgens, 11 progesterones, 10 glucocorticoids, 5 estrogens and 5 resorcylic acid lactones in cereal feeds by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Ethyl acetate was used to extract the sample, and the mixed QuEChERS sorbents were dispersed for purification. The extract was separated by a C18 column and detected in positive or negative multiple reaction monitoring (MRM) mode. With the optimal conditions, the linear ranges of 41 hormones were 5.0 - 200.0 microg/kg with the correlation coefficients above 0.99 and the limits of quantification (LOQs, S/N > or = 10) were 0.123- 2.72 microg/kg. The method validation was carried out at three spiking levels, and the recoveries were 70.3% - 118.1% for soybean meals with the relative standard deviations (RSDs) of 0.82% - 19.5%, and 76.1% - 122.8% for corn meals with the RSD of 1.3% - 15.0%. This method is simple, fast and credible, can be applied to simultaneous screening and determination of estrogens, progesterones, androgens, glucocorticoids and resorcylic acid lactones belonging to the illegal additive of hormones in cereal feeds.