Abstract:

This study developed a quick and specific method for the identification and trace quantification of 8 anabolic steroids (TS, PG, NT, MTS, BOL, TB, DIA, and STA) in milk. Samples were extracted using methyl tert-butyl ether, and the extracts were cleaned up by solid-phase extraction on a C18 (SPE) cartridge, blowed to dryness by nitrogen, and dissolved in a mixture of 10% methanol and water (10:90, V/V) prior to LC-MS/MS analysis in a multiple reaction monitoring (MRM) mode. The limits of detection (LODs) ranged in 0.2 － 0.5 μg/L, and the limits of quantification (LOQs) were between 0.5 and 1.0 μg/L. The regression equations were well linear between 2.0 and 200.0 μg/L for these steroids (r > 0.9990). The recoveries ranged from 59.1% to 97.7% with a RSD of 3.2%－11.9% (n = 3) at three spiked levels of 1.0－5.0 μg/L. The method is simple, sensitive and rapid and therefore can be used for the simultaneous determination of 8 anabolic steroids in milk.

Key words: solid-phase extraction, LC-MS/MS, anabolic steroids, milk