The Implementation and Characterization of Coaxial EESI on a Thermo ESI Source

Undergraduates: Brandon Jocher, Kenneth Swanson Gary Glish

Faculty Advisor: Gary Glish
Department: Chemistry

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Aerosolized compounds are of interest to many industries, particularly those centered around cigarettes and e-cigarettes. Aerosols may contain compounds with adverse health effects, so there is a need for an efficient and accurate means of aerosol analysis. Extractive electrospray ionization mass spectrometry (EESI-MS) is one method that can be used for sampling of aerosols in real-time. EESI involves electrospraying through a nebulized sample to extract the compounds into electrospray solvent. Coaxial EESI is a variation of EESI developed in our lab that can be used for aerosol analysis and improves upon many aspects of EESI. A Thermo Scientific Ion Max electrospray ionization (ESI) source was investigated as a potential means of performing coaxial EESI. This commercial design has concentric capillaries for optimization of gas flow, but has not been previously used for aerosol analysis. The Thermo ESI source was tested for EESI using an aerosolized standard of levoglucosan on a linear trap quadrupole and Fourier transform mass spectrometer. In this case, the electrospray solvent was spiked with 5 mM lithium acetate. The mass spectrum obtained revealed the presence of a lithiated levoglucosan peak characteristic of EESI. This confirmed using Thermo ESI as a viable means of performing coaxial EESI. Further experiments have shown that for a pyrolyzed sample of cellulose, a characteristic mass spectrum can be obtained from coaxial EESI using a Thermo ESI source.