Tetracyclines physicochemical methods

If tlie identity of the detected drug residue is still unknown after these tests have been performed, a TLC-bioautography procedure is then applied to isolate and tentatively identify the residues (64, 72). This method is not quantitative and only gives direction to the analyst as to what determinative/confirmatory method of analysis should be used. Following this tentative identification, presumptive positives are then quantified and confirmed by validated physicochemical methods. A TLC method (73) is applied for analyzing presumptive sulfonamide residues, a GC-ECD method (74) followed by a GC-MS NCI method (75) for analyzing chloramphenicol, and LC/UV methods (76,77) for analyzing -lactams and tetracyclines. 

Table 29.8 Physicochemical Methods for Tetracycline Antibacterials in Edible Animal Products... 

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