The main purpose of this proposal is to develop a novel ion source for biological mass spectrometry (MS). It will increase the ionization efficiency of biomolecules in the matrix-assisted laser desorption/ionization (MALDI) technique by post-ionizing neutral molecules desorbed into a gas phase in the MALDI process. Post-ionization will be achieved via proton transfer reactions with protonated reagent gas ions produced in the chemical ionization (Cl) source. This MALDI-CI source will be interfaced to an orthogonal acceleration time-of-flight (TOP) mass spectrometer using a quadrupole ion guide. Decoupling of the proposed ion source from the TOP mass analyzer will allow operating it at elevated pressures (approximately 1 Torr), thus increasing the effectiveness of the chemical post-ionization. By using reagent gases with different proton affinities we can induce and control the in-source fragmentation of peptide ions. Together with the increased ionization efficiency this will make mass spectrometric identification of proteins and their posttranslational modifications more sensitive and reliable.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Small Business Innovation Research Grants (SBIR) - Phase II (R44)
Project #
5R44RR017467-03
Application #
7064272
Study Section
Special Emphasis Panel (ZRG1-SSS-6 (10))
Program Officer
Sheeley, Douglas
Project Start
2002-09-01
Project End
2007-04-30
Budget Start
2006-05-01
Budget End
2007-04-30
Support Year
3
Fiscal Year
2006
Total Cost
$371,651
Indirect Cost
Name
Science and Engineering Services, Inc.
Department
Type
DUNS #
783196348
City
Columbia
State
MD
Country
United States
Zip Code
21046
Berkout, Vadym D; Doroshenko, Vladimir M (2006) Improving the quality of the ion beam exiting a quadrupole ion guide. J Am Soc Mass Spectrom 17:335-40