Application of an enzyme-linked immunosorbent assay for screening of sheep urine and animal tissue for the androgenic steroid trenbolone acetate in the state of Kuwait

This study was undertaken to determine the presence of any residue-positive meat and urine samples from live sheep in the State of Kuwait market by using an enzyme-linked immunosorbent assay (ELISA) method and to examine the accuracy and precision of the method. A total of 350 samples, including 230 sheep urine, 30 beef meat and 90 chicken, were subjected, after extraction, to an ELISA for the determination of their contents of the androgenic hormone, trenbolone acetate. The results obtained showed that the trenbolone acetate levels in the urine ranged from 0.1 to 0.9 ng/ml and in the muscle tissue from 0.02 to 0.05 ng/g all of which are below the maximum residue levels accepted (2.0 ng/g) by FAO/WHO. The mean recovery and CV, respectively, ranged from 36.7% and 5.8 (spiking level to 0.2 ng/g) to 49.6% and 10.4 (spiking level 1.5 ng/g). These results were confirmed by gas chromatography-mass spectrometry analysis (GC-MS). Based on the data obtained, it was concluded that ELISA can be used safely for screening purposes, however, any suspect sample must also be analysed by GC-MS to exclude any false positive identifications.