Submitted to: International Chemical Congress of Pacific Basin Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/9/2022
Publication Date: 12/16/2022
Citation: Shelver, W.L., Chakrabarty, S., Smith, D.J. 2022. Use of a rapid tandem mass spectrometry multi-residue method to analyze veterinary drugs and their metabolites in hog saliva and cattle urine. International Chemical Congress of Pacific Basin Meeting. Abstract.
Technical Abstract: A rapid screen electrospray ionization mass spectrometry (RS-ESI-MS) method was developed to simultaneously analyze 10 veterinary drugs or metabolites (clenbuterol, erythromycin, flunixin, 5-hydroxyflunixin, meloxicam, ractopamine, ractopamine-glucuronide, salbutamol, tylosin, and zilpaterol) in hog saliva and cow urine. A simple acetonitrile, salt-out extraction method (< 30 min) of analytes and internal standards was employed with an instrumental analysis time of 1 min/sample. Regression coefficients of matrix-matched calibration curves ranged from 0.9743 to 0.9999 across all compounds with limits of detection ranging from 0.46 to 108 ng mL-1 for cattle urine and 0.19 to 64.4 ng mL-1 for hog saliva. Recoveries for all analytes ranged between 92.7-106% for saliva and urine fortified at 30, 100, and 300 ng mL-1; inter-day variation was <20% with the exception of ractopamine-glucuronide where the recoveries varied widely and inter-day variation was 24% in cattle urine. The RS-ESI-MS method successfully identified incurred residues of ractopamine and/or ractopamine glucuronides in hog saliva and cattle urine with results corroborating traditional LC-MS/MS or HPLC fluorescence methods. Of the 10 analytes x 20 saliva samples and 20 urine samples (400 analyses total) there were no false positives. As far as we are aware, this is the first report directly quantifying ractopamine-glucuronide without lengthy hydrolysis and cleanup steps.