Determination of gestagens in kidney fat by liquid chromatography tandem mass spectrometry

The use of gestagens in animal fattening is prohibited within the European Union. Recently, the use of spectrometric methods for the detection and confirmation of banned substances was made obligatory. Therefore, conventional high-performance liquid chromatographic (HPLC) methods have been superseded. It has been possible to couple a previously described HPLC method for the determination of acetyl-gestagens in kidney fat to tandem mass spectrometry (LC-MS/MS). The decision limits CCα and the detection capability CCβ are found to be below the minimum required performance limit (MRPL) established for medroxyprogesterone acetate (MPA) at 1 μg kg−1. The calculated values for CCα are as follows: megestrol acetate (MGA)-0.15 μg kg−1, melengesterol acetate (MLA)-0.15 μg kg−1, chlormadinone acetate (CMA)-0.37 μg kg−1 and for medroxyprogesterone acetate (MPA)-0.24 μg kg−1. The CCβ values for these compounds have been determined as 0.19, 0.19, 0.47 and 0.32 μg kg−1, respectively.