Determination of 19‐nortestosterone and trenbolone in animal tissues by high‐performance liquid chromatography with immunoaffinity clean‐up

Abstract
A method for the simultaneous determination of residues of 17β‐trenbolone and 17β, 19‐nortestosterone and their epimers in animal tissues is described, involving immunoaffinity chromatography clean‐up and high‐performance liquid chromatography with dual‐wavelength UV detection. The method has been validated at 2 μg/kg in pig and cattle liver and corned beef with recoveries of 41% upwards. The method has been applied to the determination of incurred residues of 19‐nortestosterone and trenbolone. Various alternative extraction steps for incurred trenbolone have been investigated, including direct extraction, protease digestion, heating and ultrasonic probe treatment. Glucuronidase digestion has been shown to be the most effective method for this analyte.