Determination of oxytetracycline in premixes and veterinary products by liquid chromatography
Chappell, G.S.; Houglum, J.E.; Kelley, W.N.
Journal - Association of Official Analytical Chemists 69(1): 28-30
1986
ISSN/ISBN: 0004-5756 PMID: 3949693 Document Number: 272983
A liquid chromatographic method for the assay of oxytetracycline in premixes and veterinary products is described. Premix samples are extracted with acidified methanol, diluted with mobile phase and filtered before chromatography on a C-8, reverse phase column. The assay method separates oxytetracycline from epioxytetracycline, tetracycline, and chlortetracycline. Total elution time for oxytetracycline is less than 5 min at 1.5 mL/min. Five spiked premix samples each of 2 and 50 g/lb had a coefficient of variation of 3.5 and 4.5% and a mean recovery of 99 and 104%, respectively. The results of premixes and veterinary products assayed by this method compared closely with those of the same samples assayed by the official AOAC microbiological method.