METHODS FOR ASSAY OF TRIMETHOPRIM AND SULFADIAZINE IN BROILER TISSUESUSING LIQUID-CHROMATOGRAPHY

A process for the extraction of sulphadiazine (SDZ) and trimethoprim ( TMP) from broiler fortified tissues (plasma, lung, liver, kidney, fat, muscle, skin) was developed and a liquid chromatographic (LC) method for their determination is described. After extraction in acidic mediu m (pH 6.8) with ethyl acetate or dichloromethane, the extracts were pu rified with hexane-chloroform in an acidic buffer. Reversed-phase LC s eparation with gradient elution (phosphate buffer-acetonitrile) was ap plied. The values obtained for the quantification limit for both drugs are 0.100 mu g ml(-1) for plasma, 0.100 mu g g(-1) for lung and 0.050 mu g g(-1) for the other tissues. The detection limits range from 0.0 10 to 0.015 mu g g(-1) or ml(-1) and from 0.020 to 0.025 mu g g(-1) or ml(-1) for SDZ and TMP, respectively. Recoveries, established by comp arison of peak areas obtained with standards and those with fortified tissue, ranged between 85.7 and 67.2%, depending on the tissue.