Accession Number : ADA306142

Title :   Two-Laser Matrix Assisted Laser Desorption/Laser Ionization Time-of-Flight Mass Spectrometry of Biomolecules.

Descriptive Note : Final rept.,

Corporate Author : GEO-CENTERS INC NEWTON CENTRE MA

Personal Author(s) : Steadman, Jhobe

PDF Url : ADA306142

Report Date : OCT 1995

Pagination or Media Count : 22

Abstract : Recent efforts to detect and identify large biomolecules using matrix assisted laser desorption have shown MALDI to be an extremely sensitive technique for trace detection from a solid sample. In the DI process, ions are formed by proton transfer from an electronically excited organic acid to a suitable proton accepting analyte. However, detection and characterization of biomolecules may benefit from ionization of the isolated unprotonated gas phase neutrals. To this end, a custom time-of-flight mass spectrometer as been constructed to perform two-laser matrix assisted laser desorption/laser ionization studies using separate desorption and ionization lasers. The two chamber, differentially pumped apparatus incorporates numerous laser and sample probe entry ports, a pulsed valve, and a modified Wiley-NcLaren mass spectrometer design. Results of initial two-laser experiments on phenylalanine in a sinnapinic acid matrix have demonstrated the apparatus' ability to detect laser ionization of laser desorbed neutrals.

Descriptors :   *MATRIX MATERIALS, *LASERS, *IONIZATION, *MASS SPECTROMETERS, IONS, METHODOLOGY, DETECTION, SENSITIVITY, VAPOR PHASES, PROTONS, TIME, FLIGHT, CHARGE TRANSFER, DESORPTION, CHAMBERS, LASER MEDICAL DIAGNOSIS, PUMPING, BIOMOLECULES, ORGANIC ACIDS.

Subject Categories : Medicine and Medical Research
      Lasers and Masers
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE