Consecutive reaction monitoring desorption electrospray ionization mass spectrometry for rapid authentication of potentially counterfeit Tamiflu capsules

CHED 255

Kristin Johnson1, Leonard Nyadong1, Michael Green2, and Facundo M. Fernandez1. (1) School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, (2) Division of Parasitic Diseases, National Center for Infectious Diseases, Center for Disease Control and Prevention, Atlanta, GA 30333
The recent outbreak of avian influenza has increased the demand for antivirals. TamifluŽ, the leading antiviral on the market, has become a target for counterfeiters. Reports of counterfeit Tamiflu have already appeared thus creating an urgent need for rapid and sensitive TamifluŽ authentication tools. Desorption Electrospray Ionization Mass Spectrometry (DESI-MS) with consecutive reaction monitoring (CRM) is presented as a selective and rapid method to screen Tamiflu capsules with minimal sample preparation. DESI-MS analysis of genuine TamifluŽ gives predominantly the protonated monomer and dimer adducts. Doping the spray solution with crown ether gives a 1:1 protonated complex with the crown ether. MS2 analysis of this complex gives the protonated oseltamivir monomer which can be fragmented with MS3 to give the ion m/z 225. Monitoring this ion by reactive DESI creates a highly selective tool to screen oseltamivir. Screening of TamifluŽ samples collected over the internet showed that all samples contained oseltamivir.