DEVELOPMENTS IN RESIDUE ASSAY AND METABOLISM STUDY OF GROWTH-PROMOTERS BY MASS-SPECTROMETRIC ANALYSIS

The French national reference laboratory, for the control of growth-promoter residues, has developed routine methods of multiresidue analysis. These are mainly for the determination of beta-agonistic and steroid compounds. Apart from this regulatory activity, some research into growth-promoter metabolism and assay has also been carried out. This research concerns the method development of assay and metabolism studies of new compounds, including in vitro metabolism studies on cell(mainly hepatocytes) cultures, as well as studying the organic synthesis of new compounds and metabolites. Three examples of the different areas of research are presented here: the metabolism study of 4-chlorotestosterone in cattle; a methodological study on beta-agonists assay by mass spectrometry; and a residue study Of beta-agonists in edible tissues.