Abstract
Ion exchange resin column chromatography was applied to analyze residual penicillin G (PC) in the muscles and liver of swine.
PC was extracted with aqueous acetone, then absorbed on a Dowex 1×1 (Cl form) resin column and eluted with 50% acetone containing 2.0% potassium chloride. The disk plate method with Bacillus stearothermophilus var. calidolactis as the test organism was employed for the assay, and the average recoveries were 93.3% and 87.5% in muscle and liver, respectively. As little as 0.004u/g of PC was readily detectable.
The extraction and the column chromatography were carried out on samples spiked with other antibiotics in order to check the specificity of the present method. Chlortetracycline (1.0-2.5μg/g), oxytetracycline (2.5μg/g), flavophospholipol (2.5μg/g), tylosin (5.0μg/g), kitasamycin (5.0μg/g), kanamycin (5.0μg/g), bacitracin (5.0u/g) or monensin (5.0μg/g) showed no inhibition zone when the eluate from column chromatography was tested by the disk plate method.
Bioautography was suitable for confirmation of the identity of PC.
