DETERMINATION OF TRENBOLONE AND ITS METABOLITE IN BOVINE FLUIDS BY LIQUID CHROMATOGRAPHY -TANDEM MASS SPECTROMETRY

A liq. chromatog.-tandem mass spectrometric (LC-MS-MS) method was developed for the detn. of Trenbolone in bovine urine and serum. The aim was a control of the misuse of Trenbolone in food-producing animals. The procedure involved, in both cases, a preliminary solid-phase clean-up followed by a liq.-liq. extn. for urine samples after a preliminary enzymic hydrolysis. The exts. have been directly analyzed by reversed-phase LC-MS-MS in selected reaction monitoring (SRM), acquiring 2 diagnostic product ions from the chosen precursor [M+H]+. The procedures were validated across the concn. range of 1-1500 ng/mL. The linearity, the inter- and intra-day accuracy, and precision were detd. The procedure was specific and the accuracy values were better than 20% at the limit of quantitation of spiked samples. The limit of quantification (LOQ) and the limit of detection (LOD) were, resp., 1 ng/mL and 350 pg/mL for urine and serum. According to the draft, SANCO/1805/2000, the authors detd. the decision limit CC.alpha. and the detection capability CC.beta.. The recovery values for urine ranged from 87 to 128%, and for plasma the recovery was 704%. The procedure proved to be simple and suitable for routine and confirmatory purposes such as those developed for residue studies.