| Abstract: | A gas chromatographic-mass spectrometric (GC-MS) method using single ion monitoring (SIM) is described for the determination of residual macrolide antibiotics, oleandomycin, kitasamycin, spiramycin and tylosin, in beef and pork. For GC-MS determination, oleandomycin is acid hydrolysed to desoleandomycin and acetylated, in the same way as erythromycin. However, for elution from a GC column, the carbon-carbon double bonds in the antibiotics must be hydrogenated to single bonds before acid hydrolysis. Kitasamycin and spiramycin are therefore converted into hydroforocidine acetate and tylosin into hydro-O-mycaminosyl tylonolide acetate, which are determined by GC-MS with SIM. |
