ABSTRACT

Basic Information

Abstract Number: 260 - 3
Author Name: Sarah Trimpin - Wayne State University
Session Title: Pittsburgh Conference Achievement Award
Event Type: Awards
Event Title: New Ionization Methods for Mass Spectrometry for the Characterization of Biological Materials Directly from Surfaces

Presider Name:Jane Chan
Affiliation:Bechtel Bettis, Inc.

Date: Monday, March 18, 2013
Start Time: 08:10 AM (Slot #3)
Location: 114

Abstract Content

A motivation of our research is to make inroads in the daunting task of chemical analysis related to both complexity and insolubility. We recently introduced a new ionization method for use in mass spectrometry (MS) applicable to proteins which uses laser ablation of a matrix/analyte mixture similar to atmospheric pressure matrix-assisted laser desorption/ionization (MALDI) but produces mass spectra nearly identical to electrospray ionization (ESI). This new technique called laserspray ionization (LSI) has advantages of speed of analysis, high spatial resolution for imaging, mass range extension, and improved fragmentation common with multiply charged ions, even in vacuum. Crucial for the production of highly charged ions are desolvation conditions to remove matrix from charged matrix/analyte clusters. Important factors include thermal energy, vacuum assistance, collisions with gases and surfaces, as well as the sample preparation including the pH and solvent composition. Applying these concepts, highly charged ions of protein and protein complexes are produced directly from a solid matrix/analyte surface using a vacuum MALDI source without need of a laser or heat. This new cold ionization method, matrix assisted ionization vacuum (MAIV), produces similar charge states and protein conformations to ESI as determined by ion mobility spectrometry (IMS)-MS. Applications include small molecules such as drugs and body fluids including blood spots, saliva, urine, and mouse brain tissue. Producing ions under vacuum conditions in a mass spectrometer enhances sensitivity and the multiply charged ions offer the potential to use high performance mass analyzers for advanced structural characterization. Such a simple ionization method, requiring only the vacuum necessary for the proper functioning of the mass spectrometer, should prove useful in clinical settings and in field portable instruments.