Simultaneous determination of 22 residual steroid hormones in milk by liquid chromatography-tandem mass spectrometry

Food safety and consumers' health are paramount; therefore, it is essential to establish a novel method to determine hormone content in milk. Herein, a novel method was developed that can simultaneously determine 22 residual steroid hormones in milk. To obtain the maximum detection sensitivity, the preparation method of sample, mass spectrometer parameters and liquid chromatography conditions were optimised. The samples were concentrated using Oasis HLB solid-phase extraction cartridge, followed by quantification via liquid chromatography (C18 column)-tandem mass spectrometer (LC-MS). Determination of oestrogens and glucocorticoids was conducted in negative mode, whereas androgens and progesterone were in positive multiple reaction monitoring mode. The limit of detection (LOD) and limit of quantification (LOQ) of the target compounds were 0.10-1.20 mu g/kg and 0.33-3.96 mu g/kg, respectively. The average extraction recoveries of 22 steroid hormones were generally high (82.6-95.3%). The proposed method can be an effective alternative to measure hormonal compounds in milk.