A reversed-phase liquid chromatography method for determination of maduramicin in feedingstuffs and premixtures was developed, validated, and interlaboratory studied. The extraction solvent was methanol. Maduramicin was detected at 520 nm after postcolumn derivatization with vanillin. Recovery was >90ÐThe repeatability relative standard deviation (RSDr) in feeds (1-5 mg/kg) and premixtures (500 mg/kg) ranged between 2.7 and 7.7 the within-laboratory reproducibility was between 3.7 and 8.5%. The limit of quantitation was 2 mg/kg. Other feed additives did not interfere in the assay. The method showed ruggedness against small changes in the extraction conditions, eluant composition, and conditions for postcolumn derivatization. The presence of water in the extraction solvent negatively affected the recovery. In the collaborative study, 5 feeds (4 positive at 2.5-9 mg/kg, 1 blank) and 1 premixture (450 mg/kg) were analyzed by 10 laboratories. The RSDr of the feedingstuffs varied between 3.29 and 8.53ÐThe HORRAT ranged between 1.10 and 1.98. Recoveries were >90°except for one participant (80% One laboratory detected small signals in the blank sample, corresponding to 0.7 and 0.8 mg/kg. For the premixture, the RSDr was 3.15nd the HORRAT was 1.80.
|Journal||Journal of AOAC International|
|Publication status||Published - 2004|
- animal feeds
- microbiological assay
de Jong, J., Stoisser, B., Wagner, K., Tomassen, M. J. H., Driessen, J. J. M., Hofman, P., & Putzka, H. A. (2004). Determination of maduramicin in feedingstuffs and premixtures by liquid chromatography : development, validation and interlaboratory study. Journal of AOAC International, 87(5), 1033-1041. http://landbouwwagennld.library.ingentaconnect.com/content/aoac/jaoac/2004/00000087/00000005/art00001