Development of a liquid chromatography-tandem mass spectrometry method for the identification of natural androgen steroids and their conjugates in urine samples

An analytical procedure for the determination of natural steroids and their conjugates was developed and applied to bovine and human urine. Fifteen compounds (free and conjugated) after extraction by solid-phase were identified by liquid chromatography-tandem mass spectrometry (LC-MS-MS) in multiple reaction monitoring (MRM). Free and conjugated steroids were detected all together in the same chromatographic analysis respectively in positive and negative ionization. This procedure reveals to be time-saving, because it overcomes the need of further sample pre-treatment steps, such as enzymatic hydrolysis and derivatisation.The recovery for each compound was around 80%. Limit of detection of each steroid free or conjugated has been evaluated.