Metabolic profile modifications in milk after enrofloxacin administration studied by liquid chromatography coupled with high resolution mass spectrometry

• Published in: Journal of Chromatography A Vol. 1460; pp. 92 - 99
• Main Authors: Junza, A., Saurina, J., Barrón, D., Minguillón, C.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 19.08.2016
• Subjects: Animals; Cattle; Chromatography, High Pressure Liquid; Enrofloxacin; Female; Fluoroquinolones - analysis; Fluoroquinolones - chemistry; Fluoroquinolones - metabolism; High resolution mass spectrometry (HRMS); Metabolome; Metabolomics; Milk - chemistry; Multivariate analysis (PCA); Principal Component Analysis; Tandem Mass Spectrometry; Metabolomics; Multivariate analysis (PCA); High resolution mass spectrometry (HRMS); Enrofloxacin
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2016.07.016

•New compounds from enrofloxacin metabolism have been identified in milk from medicated cows.•Enrofloxacin metabolic pathway has been proposed.•Peptide compounds related to the pathology of cows have been identified.•The PCA analysis classified samples regarding concentration profile evolution of metabolites with time. High resolution accurate mass spectrometry (HRMS) operating in full scan MS mode was used in the search and identification of metabolites in raw milk from cows medicated with enrofloxacin. Data consisting of m/z features were taken throughout the entire chromatogram of milk samples from medicated animals and were compared with blank samples. Twenty six different compounds were identified. Some of them were attributed to structures related to enrofloxacin while others were dipeptides or tripeptides. Additionally, enrofloxacin was administered in a controlled treatment for three days. Milk was collected daily from the first day of treatment and until four days after in the search for the identified compounds. The obtained data were chemometrically treated by Principal Component Analysis. Samples were classified by this method into three different groups corresponding to days 1–2, day 3 and days 4–7 considering the different concentration profile evolution of metabolites during the days studied. Tentative metabolic pathways were designed to rationalize the presence of the newly identified compounds.