Study on multicomponent determination method for banned anabolic steroid residues in acidophilus milk

A rapid, specific and highly sensitive multi-residue method for the determination of seven anabolic steroid residues in acidophilus milk was developed, which was based on ultra performance liquid chrmatography-electrospray tandem mass spectrometry (UPLC-MS/MS) with positive mode under multi-reaction monitoring mode. The samples were extracted with methanol under ultrasonication and purified using LC-C18 solid phase extraction cartridge. Qualitative and quantitative analysis was carried out for the analyte under the MRM mode after the separation on Waters ACQUITY UPLCTM BEH C18 (1.7 μm, 2.1×100 mm)column. The limits of detection (LOD)of the method were from 0.011 μg/kg to 0.05 μg/kg and the limits of quantification (LOQ) were in the range of 0.037~ 0.36 μg/kg. Average recoveries for the seven anabolic steroids(spiked at the levels of 0.5 μg/kg)ranged from 83%~124%,with relative standard deviations between 8.0%~24%.