DETERMINATION OF RESIDUES OF THE BETA-AGONIST CLENBUTEROL IN LIVER OFMEDICATED FARM-ANIMALS BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY USING DIPHASIC DIALYSIS AS AN EXTRACTION PROCEDURE

A method has been developed for the rapid confirmation of clenbuterol in cow liver using gas chromatography coupled with detection by mass s pectrometry of the trimethylsilyl derivatives of clenbuterol. The tech nique used for the extraction was diphasic dialysis. It was observed t hat the best suitable solution to homogenize the liver the barium hydr oxide-barium chloride buffer, the optimal extraction solvent was tert. -butylmethyl ether at an extraction temperature of 37 degrees C, and s tirring should be applied at 150 rpm for 4 h. This extraction method i mproves clenbuterol recovery up to values of 99.3%. With the use of th e barium buffer, derivatization is performed more efficiently and the detection and quantification limits can be decreased to values close t o 250 ppt and 500 ppt, respectively.