Method for confirmation of synthetic corticosteroids in doping urine samples by liquid chromatography-electrospray ionisation mass spectrometry.
In this study, we report on the development of a method to confirm simultaneously nine of the most commonly abused synthetic corticosteroids in urine based on liquid chromatography-electrospray ionisation mass spectrometry. A considerable simplified sample preparation procedure, including liquid-liquid phase extraction with Extrelut-NT3 columns, provided both excellent sample purification and high overall recoveries. Complete HPLC separations were obtained on a reversed-phase column with 1 mM ammonium acetate-acetonitrile (60:40, v/v) as mobile phase. Mass spectral acquisition was done in the negative ion, and selected ion monitoring modes to identify the drugs with at least three characteristic ions. Detection limits were determined at < or =1 ng/ml and the confirmation limits at 1 to 5 ng/ml.