title: Microbiological method for determining macrolides in animal feeds in the presence of other drugs by thin-layer chromatography detection.
abstract: A method was developed to separate, detect, and quantitate erythromycin (ERY) and tylosin (TYL) in animal feeds in the presence of 11 other drugs: 3 nitrofurans, 2 tetracycline antibiotics, 3 sulfonamides, 2 coccidiostats, and 1 antibacterial growth promoter. ERY and TYL were separated from coexisting drugs, detected by thin-layer chromatography, and quantitated microbiologically by an agar diffusion method. Analysis of 125 experimental animal feed samples fortified at 5 levels (7.5-400 ppm) with ERY and TYL and at 1 level (50 ppm) with the rest of the drugs gave limits of quantitation of 2 and 5 ppm, recoveries of 90.3 and 92.4%, and relative standard deviations of 4.3-7.3% and 3.6-6.1%, respectively.
authors.affiliation: Aristotle University, School of Veterinary Medicine, Laboratory of Animal Nutrition, Thessaloniki, Greece.
authors.forename: P K
authors.initials: PK
authors.lastname: Markakis
mesh_terms: D000362:Agar / Q000737:chemistry; D000821:Animal Feed / Q000032:analysis*; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D001681:Biological Assay; D002855:Chromatography, Thin Layer; D003049:Coccidiostats / Q000032:analysis / Q000737:chemistry; D003470:Culture Media; D004058:Diffusion; D004917:Erythromycin / Q000032:analysis* / Q000302:isolation & purification; D005527:Food, Fortified; D006863:Hydrogen-Ion Concentration; D008837:Micrococcus / Q000187:drug effects; D009581:Nitrofurans / Q000032:analysis / Q000737:chemistry; D011810:Quinoxalines / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D012385:Ronidazole / Q000032:analysis / Q000737:chemistry; D013449:Sulfonamides / Q000032:analysis / Q000737:chemistry; D013754:Tetracyclines; D015645:Tylosin / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D003049:Coccidiostats; D003470:Culture Media; D009581:Nitrofurans; D011810:Quinoxalines; D013449:Sulfonamides; D013754:Tetracyclines; D004917:Erythromycin; D000362:Agar; D012385:Ronidazole; C013168:olaquindox; D015645:Tylosin