Tandem Fourier transform mass spectrometry of large molecules

Miscellaneous · Mon Jan 01 00:00:00 EST 1990

OSTI ID:5775722

Williams, E R

Fourier-transform mass spectrometry has a number of key advantages, including simultaneous ion detection over a wide mass range, ultra-high resolution, and extensive capabilities for tandem mass spectrometry (MS/MS, even MS{sup n}). Here, new methods for soft ionization including {sup 252}Cf plasma desorption, 193 nm laser desorption, multiphoton ionization, and electrospray ionization (ESI) are demonstrated to produce abundant molecular ion species from a variety of compounds; ESI spectra of peptides as large as carbonic anhydrase (29,000 Da) with as many as 33+ charges are shown. Sensitivity can be improved up to 100x by remeasuring high mass ions multiple times; after excitation to a larger orbit for detection, energy lost through collisions with background neutrals returns these ions to the center of the cell where they are available for detection or dissociation in subsequent measurements. Photodissociation with 193 nm deposits 6.4 eV per photon absorbed, and produces spectra with extensive sequence information for a variety of peptides with dissociation efficiencies approaching 100%. Surface induced dissociation is demonstrated to produce structurally-useful fragmentation for peptides up to m/z 3100, a mass range where collisionally activated dissociation provides little information. Sensitivity for MS/MS and MS{sup n} measurements is substantially improved by simultaneously recording MS-II spectra of scores of precursors using the Hadamard deconvolution approach. Results with an eleven component mixture demonstrate a signal-to-noise (S/N) gain of 1.8x, as predicted by theory. A Hadamard of differences method is proposed in which all precursors are simultaneously dissociated such that posed in which all precursors are simultaneously dissociated such that MS{sup n} spectra of each of these could be obtained without additional time or sample over measuring just one (with the same S/N) individually.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 5775722
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
MASS SPECTROSCOPY
TECHNOLOGY ASSESSMENT
PEPTIDES
CHEMICAL ANALYSIS
DATA ANALYSIS
DISSOCIATION
FOURIER TRANSFORMATION
FRAGMENTATION
IONIZATION
LASERS
MASS SPECTRA
MOLECULAR WEIGHT
PHOTOIONIZATION
PROTEINS
SENSITIVITY
SIGNAL-TO-NOISE RATIO
INTEGRAL TRANSFORMATIONS
ORGANIC COMPOUNDS
SPECTRA
SPECTROSCOPY
TRANSFORMATIONS
400102* - Chemical & Spectral Procedures