title: Pad-plate diffusion assay for virginiamycin in mash-type feeds.
abstract: An assay procedure has been developed for virginiamycin in mash-type feeds which includes removing fat interferences from the feeds by a rapid petroleum ether wash, a citric acid extraction, an acetone extraction, and the use of the pad-plate diffusion system. The procedure eliminates the need for compensatory curves prepared from feeds of the same or similar composition. Recoveries from 10 laboratory-prepared feeds containing 11.0 micrograms virginiamycin/g averaged 89.3% with a coefficient of variation (CV) of 5.76%. Recoveries from a laboratory-prepared feed containing 13.2 micrograms virginiamycin/g averaged 89.9% (CV 9.92%). The procedure is simple, reasonably accurate, and precise.
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000494:pharmacology; D003470:Culture Media; D004058:Diffusion; D008826:Microbial Sensitivity Tests; D008837:Micrococcus / Q000187:drug effects; D011200:Poultry; D014769:Virginiamycin / Q000032:analysis* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D014769:Virginiamycin