On the formation of artefact peaks in linked scans of the magnet and electric sector fields in a mass spectrometer

1977 ◽  
Vol 12 (12) ◽  
pp. 735-738 ◽  
Author(s):  
R. P. Morgan ◽  
C. J. Porter ◽  
J. H. Beynon
Keyword(s):  
Mass Spectrometer ◽  
Electric Sector

High-Resolution Time-of-Flight Spectra Obtained Using the MULTUM II Multi-Turn Type Time-of-Flight Mass Spectrometer with an Electron Ionization Ion Source

2005 ◽  
Vol 11 (3) ◽  
pp. 261-266 ◽  
Author(s):  
Daisuke Okumura ◽  
Michisato Toyoda ◽  
Morio Ishihara ◽  
Itsuo Katakuse
Keyword(s):  
Mass Spectrometer ◽  
Mass Difference ◽  
Time Of Flight ◽  
Ion Source ◽  
Electron Ionization ◽  
Mass Resolution ◽  
Resolving Power ◽  
High Mass ◽  
Electric Sector ◽  
Mass Resolving Power

This paper describes experiments demonstrating the high mass-resolving power of the MULTUM II multi-turn type time-of-flight (ToF) mass spectrometer with a 1.308-meter circuit controlled by four toroidal electric sector fields1 and an electron ionization (EI) ion source. A mass resolution of 250,000 [full-width at half maximum: (FWHM)] was obtained for N2+ after a flight time of 9.0 ms (flight cycles: 1200, flight length: 1500 m). A doublet of 12C5H514N and 13C12C5H6 ( m/Δ m = 9746; Δ m: mass difference of doublet, m: mass of lighter ion of doublet) was separated and a mass resolution of 91,000 (FWHM) was obtained. A doublet of CDCl2 and CH2Cl2 ( m/Δ m = 54,162) was also separated. A mass resolution of 115,000 (FWHM) was then achieved. When one peak of these doublets was used as a calibrant, the mass of the other peak was determined within a few ppm by mass difference. The ToF depending on the square of m/z was significantly larger than the systematic errors in the ToF, so that good mass accuracy was obtained by one-point mass determination.

Design of a high-resolution mass spectrometer for studying the photodissociation of organic ions in the gas phase

1981 ◽  
Vol 374 (1759) ◽  
pp. 461-473 ◽  
Keyword(s):  
Mass Spectrometer ◽  
Ion Source ◽  
Operating Conditions ◽  
Electron Multiplier ◽  
Electric Sector ◽  
Positive Ions ◽  
Free Region ◽  
Field Free Region ◽  
Ion Laser ◽  
Double Focusing

The design and operating conditions of an apparatus to study photodissociation of ions is described. Ions in a large, double-focusing, mass spectrometer are irradiated with photons from an argon-ion laser. A path length of 706 mm for interaction between the ion and laser beams is obtained by passing the radiation through the ion source and then along the same path as that followed by the ions in the first field-free region of the mass spectrometer. By scanning the voltage of the electric sector, different fragment ions resulting from photodissociation are transmitted in turn to an electron multiplier. They are distinguished from ions resulting from unimolecular dissociation by mechanically chopping the laser beam and using the technique of phase-sensitive detection. The photodissociations of the molecular, positive ions of the three isomers of nitrotoluene have been investigated. It is found that, after excitation of the ions with 2.541 eV photons, the resulting fragmentation pathways are different from those for the corresponding unimolecular dissociations.

A TIME-OF-FLIGHT MASS SPECTROMETER FOR SIMS AND FIELD IONISED NEUTRAL ANALYSIS USING A PULSED LMIS

1987 ◽  
Vol 48 (C6) ◽  
pp. C6-577-C6-582 ◽  
Author(s):  
A. R. Waugh ◽  
D. R. Kingham ◽  
C. H. Richardson ◽  
M. Goff
Keyword(s):  
Mass Spectrometer ◽  
Time Of Flight ◽  
Flight Mass Spectrometer
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