SCREENING AND CONFIRMATORY DETERMINATION OF CLENBUTEROL RESIDUES IN BOVINE MEAT MARKETED IN THE NORTHWEST OF MEXICO

It is essential from the public health point of view, that the Mexican regulatory agencies implement a monitoring surveillance program that not only uses preliminary screening methods for the determination of clenbuterol, but also uses confirmatory methods such as MS-MS techniques. Thus, the aim of this work was to monitor the presence of clenbuterol residues in bovine meat muscle collected from the local market. From 50 bovine meat samples analyzed by the ELISA test, 6 (12 %) presented clenbuterol residues from 3.06 to 6.12 mu g/kg, 13 (26 %) from 0.5 to 1.83 mu g/kg, 24 (48 %) from 0.1 to 0.5 mu g/kg and only 7 (14 %) were below the limit of detection (LOD) of 0.1 mu g/kg. The six samples with the highest clenbuterol residues were subjected to GC-MS-MS for confirmation. The results showed that clenbuterol was illegally used as a bovine growth promoter.