Laser-based studies with an ion-trap mass spectrometer: Ion tomography and analytical applications

Conference · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7207015

Alexander, M L; Cisper, M E; Hemberger, P H; Nogar, N S ^[1]; Williams, J D ^[2]; Syka, J E.P. ^[3]

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1. Los Alamos National Lab., NM (United States)
2. Purdue Univ., Lafayette, IN (United States). Dept. of Chemistry
3. Finnigan MAT, San Jose, CA (United States)

The iron trap mass spectrometer (ITMS) is an ion storage device which consists of two hyperbolic endcaps and a hyperbolic ring electrode. This forms a trapping cavity having a volume of several cm{sup 3}. An rf potential applied to the ring electrode produces a time-varying potential which can be used to trap and/or manipulate ions under controlled conditions. This device has been used in ion trapping studies for a number of years. More recently, a commercial version has been produced and sold which allows for mass-selective ejection of trapped ions, with subsequent detection by an electron multiplier. In this mode, it operates as a compact, high efficiency, high resolution mass spectrometer. The instrument has found applications in GC/MS, in tandem mass spectroscopy and in portable mass spectral analysis. In this manuscript, we present a survey of recent results incorporating laser desorption, ionization, or photodissociation with ITMS. In one instance, we describe the use of laser photodissociation to map the spatial distribution of trapped ions in the ITMS. In this tomographic study, we have parameterized the effects of trapping potential, buffer gas pressure, supplementary rf-potential, and laser intensity. In separate studies, laser desorption was used to generate gas phase ions in the ITMS from a solid probe, by irradiation of both neat and matrix-dissolved samples. The latter experiment produced both high molecular weight ions, and significant numbers of negative ions. 6 refs.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7207015
• Report Number(s): LA-UR-92-1862; CONF-920574--10; ON: DE92017529
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
440800 -- Miscellaneous Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
DESORPTION
DIAGNOSTIC TECHNIQUES
DISSOCIATION
ELECTROMAGNETIC RADIATION
IONIZATION
LASER RADIATION
MASS SPECTROMETERS
MASS SPECTROSCOPY
MEASURING INSTRUMENTS
ORGANIC COMPOUNDS
PERFORMANCE
RADIATIONS
RF SYSTEMS
SORPTION
SPECTROMETERS
SPECTROSCOPY
TOMOGRAPHY
TRAPPING
TRAPS