Speaker: Charles N. McEwen, PhD; Houghton Endowed Chairholder in Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA

Topic: Matrix Assisted Ionization: Understanding Ionization Mechanisms and Miniaturizing Mass Spectrometers

Date: Monday, December 14, 2015

Time: 6:15 pm: Dinner and Social Hour; 7:15 pm: Presentation; (Student Presentation: 7:10 pm;Amanda Lee-Fenselau Group)

Location: Shimadzu Scientific Instrument, Inc. Training Center 7100 Riverwood Drive, Columbia, MD 21046 (Directions)

Dinner and Social Hour Please RSVP to Jace Jones(jjones@rx.umaryland.edu) if you will be attending dinner.

Abstract: The proliferation of mass spectrometers and numerous advances in science have occurred because of discoveries for converting compounds, regardless of volatility, to gas-phase ions using minute quantities of analyte. ESI and MALDI are the most well-known examples, but more recently matrix-assisted ionization (MAI) methods have been introduced that are operationally similar to MALDI but produce ESI-like charge states, thus, seemingly linking the mechanism of ESI and MALDI. Like ESI and MALDI, MAI is highly sensitive but requires neither high voltage nor a laser to generate ions. Solid MAI matrices were recently discovered which transfer volatile and nonvolatile, low and high-mass compounds to gas-phase ions without application of any external energy, eliminating the need for high voltage, lasers, and heaters. Ions are spontaneously produced when the matrix:analyte is exposed to the sub-atmospheric pressure required for all mass spectrometers. In this presentation, the mechanism of MAI and its link to ESI and MALDI will be discussed along with the potential of MAI to advance field portable and low-cost mass spectrometers in such areas as reaction monitoring, environmental analysis, and clinical applications.