Pulsed laser desorption

TOF mass spectrometry is ideally suited to those ionization methods that inherently produce ions in pulses, as with pulsed laser desorption or Cf-radionuclide ionization. 

A mechanized off-line fraction collection from a microbore LC column on an indented sample holder, which is subsequently analysed by pulsed laser desorption MS, was described in 1983 by Huber et al. [68],... 

Brandbyge M, Hedegard P, Heinz TF, Misewich JA, Newns DM (1995) Electronically driven adsorbate excitation mechanism in femtosecond-pulse laser desorption. Phys Rev B 52 6042... 

Arrowsmith, R, de Vries, M.S., Hunziker, H.E., and Wendt, H.R., "Pulsed Laser Desorption Near a Jet Orifice Concentration Profiles of Entrained Perylene Vapor," Applied Physics B 46(2), 165-173,1988. 

Li, L. and Lubman, D., "Pulsed Laser Desorption Method for Volatilizing Thermally Labile Molecules for Supersonic Jet Spectroscopy," Rev. Sci Instrum. 59, 557-561, 1988. 

We describe here the important role that quadrupole ion traps (both the classic 3D ion trap and the linear ion trap) have played, and will continue to play, in imaging mass spectrometry (IMS) (which is not to be confused with Ion Mobility Spectrometry (IMS)). The pulsed mode of operation of an ion trap is an ideal match to a pulsed laser desorption event. Even more important, quadrupole ion traps provide Mass spectrometry/Mass spectrometry MS/MS (and MS"), which is critical for the mapping of individnal compounds in complex samples such as tissue, and for... 

Ion Trap The first demonstration of full-scan MS/MS data for MALDI imaging was obtained with a three-dimesional (3D) quadrupole ion trap (QIT) (Troendle et al., 1999 Garrett et al., 2005). These experiments were performed on an instrument constructed at the University of Florida and clearly demonstrated the critical role of MS/MS for imaging small molecules in tissue. The use of ion traps for MSI has been reviewed (Garrett and Yost, 2009). The QIT can trap and store ions from a pulsed laser desorption event in contrast, quadrupole mass spectrometers and other scanning instruments are... 

Li, L. and Lubman, D.M. 1989. Resonant two-photon ionization spectroscopic analysis of thin-layer chromatography using pulsed laser desorption/volatilization into supersonic jet expansions. Ana/. Chem., 61 1911-1915. 

Gas-phase spectroscopy of neutral molecules, as opposed to ions, usually involves the use of supersonic molecular beams [1 ]. For smaller compounds this can be achieved by seeding in the inert drive gas. This limitation excludes the study of neutral nucleosides or larger compounds while even some of the bare nucleobases, such as guanine, cannot be sufficiently heated without thermal degradation. Some work with bases and base mimics has been done in seeded beams [5-10]. Larger compounds can now be vaporized successfully by pulsed laser desorption, followed by entrainment in a supersonic jet [11-14]. This experimental advance has opened up the field of study of nucleobases and nucleosides in isolation in the gas phase, especially by IR spectroscopy. The cooling in molecular beams makes this approach particularly attractive for spectroscopy. Although temperatures are not as low as in ion traps or helium droplets, molecular beams can achieve internal temperatures typically of the order of 10-20 K, which provides very useful optical resolution. 

Arrowsmith P, de Vries MS, Hunziker HE, Wendt HR (1988) Pulsed laser desorption near a jet orifice concentration profiles of entrained perylene vapor. Appl Phys B 46 165-173... 

Tembreull R, Lubman DM (1987) Resonant two-photon ionization of small peptides using pulsed laser desorption in supersonic beam mass spectrometry. Anal Chem 59 1003-1006... 

Fig. 10.10 (a) Schematic diagram of an experimental setup for the REMPI of biological molecules volatihzed by way of pulsed laser desorption in a supersonic jet (b)-(d) laser desorption time-of-flight mass spectra of various molecules ionized by UV pulses at (b) 280 nm, (c) 266 nm, and (d) 280 nm. (Adapted from Lubman and Li 1990.)... 

Lubman, D. M., and Li, Liang (1990). Resonant two-photon ionization spectroscopy of biological molecules in supersonic jets volatilized by pulsed laser desorption. In Lasers and Mass-Spectrometry (ed. D. M. Lubman), pp. 352-382. Oxford University Press, New York. 

Li, L. Lubman, D. M. Resonance-enhanced multiphoton ionization jet spectroscopy and mass-spectrometry of tyrosine-containing dipeptides using a pulsed laser desorption-volatilization method. Applied Spectroscopy 1989, 43, 543-549. 

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