| Abstract: | A simple, new method permitting the simultaneous determination and confirmation of trace residues of 24 different growth promoters and metabolites using liquid chromatography-mass spectrometry was developed and validated. The compounds were extracted from bovine tissue using acetonitrile; sodium sulphate was also added at this stage to aid with purification. The resulting mixture was then evaporated to approximately 1?ml and subsequently centrifuged at high speed and an aliquot injected onto the LC-MS/MS system. The calculated CCα values ranged between 0.11 and 0.46?µg?kg?1; calculated CCβ were in the range 0.19–0.79?µg?kg?1. Accuracy, measurement of uncertainty, repeatability and linearity were also determined for each analyte. The analytical method was applied to a number of bovine tissue samples imported into Ireland from third countries. Levels of progesterone were found in a number of samples at concentrations ranging between 0.28 and 30.30?µg?kg?1. Levels of alpha- and beta-testosterone were also found in a number of samples at concentrations ranging between 0.22 and 8.63?µg?kg?1 and between 0.16 and 2.08?µg?kg?1 respectively. |
