Suitability of feathers as control matrix for antimicrobial treatments detection compared to muscle and liver of broilers

Widespread antibiotic use and the antimicrobial resistance phenomenon demand new analytical methods and the use of non-conventional matrices increasingly necessary for safe food control. We present a method developed to detect six common antibiotics used in poultry breeding, in the unconventional matrix, feathers, compared to muscle and liver. The analysis for the presence of two b-lactams (penicillin V, amoxicillin), two fluoroquinolones (enrofloxacin, ciprofloxacin), one phenicol (thiamphenicol) and one macrolide (tylosin) was validated and achieved by HPLC-HRMS, with the ultimate aim to identify untargeted metabolites in broilers subjected to different therapeutic protocols. All the validated method parameters met the regulatory requirements. Muscle and liver were not effective matrices when the withdrawal periods were largely respected. Conversely, feathers proved a promising matrix for the detection of all the studied antibiotics, in the range of 8.72e1885.32 ng g-1, except penicillin V. Like other nonconventional matrices, such as teeth, the antibiotics detected in feathers existed in their unmetabolised form.