Determination of ketosteroid hormones in meat by liquid chromatography tandem mass spectrometry and derivatization chemistry

A method for the determination and quantification of ketosteroid hormones in meat by mass spectrometry, based on the derivatization of the carbonyl moiety of steroids by Omethylhydroxylamine, is presented. The quantitative assay is performed by means of multiple-reaction-monitoring (MRM) scan mode and using the corresponding labelled species, obtained by reaction with d3-methoxylamine, as internal standard. The accuracy of the method was established by evaluating artificially spiked samples, obtaining values in the range 90-110 %. Recovery tests were performed on blank matrix samples spiked with non-natural steroids including trenbolone and melengestrol acetate. The latter experiment revealed that the yield of the extraction processes was approximately 60 %. Good values of LOQ and LOD were achieved, making this method competitive with current hormone assay methods.