An improved method for the determination of bacitracin in animal feeds

Abstract

The determination of small amounts of bacitracin in animal feeds has been studied. It was expected that by using acidified methanol as the only organic solvent in the extraction procedure and phosphate buffer, undesired proteins would not be dissolved and the use of the toxic solvent pyridine might be avoided. Bacitracin could then be determined in the final extract by using microbiological methods, in which methanol interferes less than pyridine. The method reported here has been used for feed mixtures with various zinc bacitracin contents in the range from 5 to 350 p.p.m.