LIQUID-CHROMATOGRAPHY THERMOSPRAY MASS-SPECTROMETRIC ASSAY FOR TRENBOLONE IN BOVINE BILE AND FECES

A liquid chromatography-thermospray mass spectrometric assay was devel oped and validated to confirm the presence of illegal residues of the synthetic androgenic growth promoter, trenbolone acetate, in cattle. T he assay was specific for 17alpha-trenbolone, the major bovine metabol ite of trenbolone acetate. Methods were developed for the determinatio n of 17alpha-trenbolone in both bile and faeces, the most appropriate matrices for the control of trenbolone acetate abuse. The clean-up.pro cedure developed relied on enzymatic hydrolysis, followed by sequentia l liquid-liquid and liquid-solid extraction. The extracts were then su bjected to immunoaffinity chromatography. 17alpha-Trenbolone was detec ted by selected ion monitoring at m/z 271 using positive ion thermospr ay ionisation. The limit of detection was approximately 0.5 ng/g in fa eces and 0.5 ng/ml in bile.