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

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