Turbidimetric assay of penicillin in feeds: addition of magnesium sulfate to eliminate chlortetracycline interference
Chiang, T.; Hanks, A.R.; Melton, J.R.; Hoover, W.L.
Journal - Association of Official Analytical Chemists 66(1): 184-187
1983
ISSN/ISBN: 0004-5756 PMID: 6826505 Document Number: 221113
The official AOAC [Association of Official Analytical Chemists] method for extracting penicillin from feeds allows some chlortetracycline to be coextracted if the latter is also present in the sample. This can cause a high bias in results obtained by using the turbidimetric assay in which the test organism is sensitive to both antibiotics. Mg ions can be used to circumvent the interference of chlortetracycline in the turbidimetric assay for penicillin.