Comparison of purification procedures for the isolation and detection of anabolic residues in faeces using gas chromatography-mass spectrometry.

Within several regional field laboratories and the national reference laboratory a harmonised methodology for the analysis of anabolic residues in faecal samples was developed. The method consists of a liquid-liquid and a solid-phase extraction step, followed by a high-performance liquid chromatography purification step. Using gas chromatography-mass spectrometry, currently illegally used anabolic steroids can be detected in faeces at the ppb level. Within this context acidification, followed by centrifugation under cooling, allows efficient, practical and rapid defatting of faecal samples. Furthermore, a combination of a silica and an aminopropyl solid-phase extraction column was found to give the best results as regards the sample purification process.