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Laser desorption and time-of-flight mass spectrometry. Fundamentals .Applications; Desorption laser et spectrometrie de masse par temps de vol. Aspects fondamentaux. Applications

Abstract

Time-of-flight mass spectrometry is a very powerful technique for the analysis of heavy molecular ions (100 000 u and more). The ejection in the gas phase and the ionization of these molecules is now possible through the MALDI technique (Matrix Assisted Laser Desorption Ionization). This technique consists in mixing the heavy molecules to be analysed with a organic matrix which absorbs at the wavelength of the laser. The necessary irradiance are of the order of 10{sup 6} W/cm{sup 2}. In these conditions we have shown that the mass resolutions are optimum and that the relative mass accuracies are of the order of 10{sup -4}. We have also demonstrated that the emission angle of the molecular ions in MALDI depends on the incident angle of the laser light. During the desorption process, the molecular ions are emitted in the opposite direction of the incident laser light. This effect is particularly important for the design of the accelerating stage of the time-of-flight spectrometers. Problems relative to the detection of these heavy molecular ions have been studied in details between 0.5 10{sup 4} m/s and 10{sup 5} m/s. The velocity threshold of the electronic emission is lower than the value of 0.5 10{sup  More>>
Authors:
Publication Date:
Nov 01, 1994
Product Type:
Thesis/Dissertation
Report Number:
IPNO-T-94-04
Reference Number:
SCA: 400101; 360606; PA: AIX-26:051894; EDB-95:091623; ERA-20:018924; NTS-96:003009; SN: 95001413300
Resource Relation:
Other Information: TH: These (D. es Sc.).; PBD: Nov 1994
Subject:
40 CHEMISTRY; 36 MATERIALS SCIENCE; LASER RADIATION; DESORPTION; PHOTOIONIZATION; OTHER ORGANIC COMPOUNDS; TIME-OF-FLIGHT MASS SPECTROMETERS; CESIUM IODIDES; ELECTRON EMISSION; FULLERENES; HEAVY IONS; MASS RESOLUTION; MOLECULAR WEIGHT; MULTICHARGED IONS; STRUCTURAL CHEMICAL ANALYSIS; ULTRAVIOLET RADIATION
OSTI ID:
66078
Research Organizations:
Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Paris-11 Univ., 91 - Orsay (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
Other: ON: DE95630630; TRN: FR9501915051894
Availability:
INIS; OSTI as DE95630630
Submitting Site:
FRN
Size:
173 p.
Announcement Date:

Citation Formats

Chaurand, P. Laser desorption and time-of-flight mass spectrometry. Fundamentals .Applications; Desorption laser et spectrometrie de masse par temps de vol. Aspects fondamentaux. Applications. France: N. p., 1994. Web.
Chaurand, P. Laser desorption and time-of-flight mass spectrometry. Fundamentals .Applications; Desorption laser et spectrometrie de masse par temps de vol. Aspects fondamentaux. Applications. France.
Chaurand, P. 1994. "Laser desorption and time-of-flight mass spectrometry. Fundamentals .Applications; Desorption laser et spectrometrie de masse par temps de vol. Aspects fondamentaux. Applications." France.
@misc{etde_66078,
title = {Laser desorption and time-of-flight mass spectrometry. Fundamentals .Applications; Desorption laser et spectrometrie de masse par temps de vol. Aspects fondamentaux. Applications}
author = {Chaurand, P}
abstractNote = {Time-of-flight mass spectrometry is a very powerful technique for the analysis of heavy molecular ions (100 000 u and more). The ejection in the gas phase and the ionization of these molecules is now possible through the MALDI technique (Matrix Assisted Laser Desorption Ionization). This technique consists in mixing the heavy molecules to be analysed with a organic matrix which absorbs at the wavelength of the laser. The necessary irradiance are of the order of 10{sup 6} W/cm{sup 2}. In these conditions we have shown that the mass resolutions are optimum and that the relative mass accuracies are of the order of 10{sup -4}. We have also demonstrated that the emission angle of the molecular ions in MALDI depends on the incident angle of the laser light. During the desorption process, the molecular ions are emitted in the opposite direction of the incident laser light. This effect is particularly important for the design of the accelerating stage of the time-of-flight spectrometers. Problems relative to the detection of these heavy molecular ions have been studied in details between 0.5 10{sup 4} m/s and 10{sup 5} m/s. The velocity threshold of the electronic emission is lower than the value of 0.5 10{sup 4} m/s. The relation between the electronic emission and the projectile velocity is complex. Finally, examples on mass identification of C{sub 60} molecules and derivated C{sub 60} are presented. Desorption methods are compared. (author). 32 refs., 34 figs.}
place = {France}
year = {1994}
month = {Nov}
}