Two-Laser Matrix Assisted Laser Desorption/Laser Ionization Time-of-Flight Mass Spectrometry of Biomolecules.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1995
- Accession Number
- ADA306142
Entities
People
- Jhobe Steadman