|CHAKRABARTY, SHUBHASHIS - North Dakota State University|
|YOUNG, JENNIFER - North Dakota State University|
|BYRD, CHRISTOPHER - North Dakota State University|
Submitted to: Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2021
Publication Date: 12/23/2021
Citation: Shelver, W.L., Chakrabarty, S., Young, J.M., Byrd, C.J., Smith, D.J. 2021. Evaluation of rapid and standard tandem mass spectrometric methods to analyze veterinary drugs and their metabolites in hog oral fluid and cattle urine. Food Additives & Contaminants. 39:462-474. https://doi.org/10.1080/19440049.2021.2006801.
Interpretive Summary: A rapid analysis system was developed for quantifying 10 animal drugs or their metabolites in cattle urine and hog saliva. Urine and saliva were chosen because they can be easily obtained from live animals to determine whether drug exposure has occurred. Detecting drug residues in live animals prevents potential economic loss due to product rejection after animal slaughter. This research investigated the suitability of a new extraction technique for use with a recently developed rapid (< 1 min) analytical method. In addition, the new extraction method allowed the determination of a polar metabolite, which previously had to be determined by complex analytical methods. Collectively, the extraction and analytical methods proved to be superior in many respects to existing technologies.
Technical Abstract: A multi-residue, rapid screen electrospray ionization mass spectrometric (RS-ESI-MS) method was developed to analyze 10 veterinary drugs or metabolites (clenbuterol, erythromycin, flunixin, 5-hydroxyflunixin, meloxicam, ractopamine, ractopamine-glucuronide, salbutamol, tylosin, and zilpaterol) in hog oral fluid and bovine urine. Simple acetonitrile extraction with salting-out was employed to remove the analytes from matrices in less than 30 minutes. Instrumental analysis time was < 1 min/injection. Regression coefficients of matrix-matched calibration curves ranged 0.9743-0.9999 across all compounds with limits of detection ranging from 0.46-108 ng mL-1 for cattle urine and 0.19-64.4 ng mL-1 for hog oral fluid across all analytes. Except for ractopamine-glucuronide, analyte recoveries ranged from 92.7-106% for oral fluid and urine fortified at 30, 100, and 300 ng mL-1 with inter-day variations of < 25%. The RS-ESI-MS method accurately identified ractopamine and/or ractopamine-glucuronide in incurred cattle urine with results correlating well with traditional LC-MS/MS and HPLC fluorescence methods. As far as we are aware, this is the first report of the direct quantification of ractopamine-glucuronide from biological matrices without lengthy hydrolysis and cleanup steps.