Determination and Confirmation of the Antiviral Drug Amantadine and Its Analogues in Chicken Jerky Pet Treats

In this study, we investigated two methods for the detection of antiviral compounds in chicken jerky pet treats. Initially, a screening method developed to detect many different chemical contaminants indicated the presence of amantadine, 1, in some pet treats analyzed. A second antiviral-specific method was then developed for amantadine and its analogues, rimantadine, 2, and memantine, 3. Both methods used an acidic water/acetonitrile extraction. The antiviral-specific method also included a dispersive sorbent cleanup. Analytes were detected and identified by LC-MS (ion trap and Orbitrap) instruments. The antiviral-specific method was validated by analyzing matrix blanks and fortified samples (2.5-50 mu g/kg levels). Average recoveries for amantadine (using a deuterated internal standard) in fortified samples ranged from 76 to 123% with relative standard deviations of <= 12%. Amantadine was detected and identified in suspect chicken jerky pet treat samples at levels ranging from <2.5 mu g/kg to over 600 mu g/kg. Rimantadine and memantine were not detected in any samples.