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