Determination of avilamycin in poultry feeds by liquid chromatography

Avilamycin was extracted from feed with acetonitrite, Isolation of avilamyc in factors from feed matrix interference was accomplished by normal-phase s olid-phase extraction with silica as sorbent, Reversed-phase liquid chromat ography was subsequently used to separate and quantitate the primary biolog ically active factors A and B for determination of chemical potency. This m ethod combines specificity for avilamycins A and B in poultry feeds with si mple sample preparation that removes matrix interferences. Recoveries of fa ctor A ranged from 93.29 to 97.26%, with precision (relative standard devia tion) ranging from 1.1 to 3.4%, Avilamycin factors in feed samples tested r anged from 4.45 to 17.82 mu g/g for factor A and from 0.80 to 3.18 mu g/g f or factor B.