Filtered noise field signals for mass-selective accumulation of externally formed ions in a quadrupole ion trap

Journal Article · Mon Jan 31 23:00:00 EST 1994 · Analytical Chemistry (Washington); (United States)

DOI:https://doi.org/10.1021/ac00075a001· OSTI ID:7275099

Goeringer, D E; Asano, K G; McLuckey, S A ^[1]; Hoekman, D ^[2]; Stiller, S W ^[3]

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1. Oak Ridge National Lab., TN (United States)
2. Teledyne Electronic Technologies, Mountain View, CA (United States)
3. Hitachi Instruments, Inc., San Jose, CA (United States)

A new wideband resonance excitation technique, termed a filtered noise field (FNF), is demonstrated for selective accumulation of externally formed ions in the rf quadrupole ion trap. Data obtained for detection of trinitrotoluene (TNT) and black powder vapors in ambient air, via atmospheric sampling glow discharge ionization (ASGDI), indicate that a notch-filtered FNF signal applied to the endcap electrodes can prevent accumulation of matrix ions without adversely affecting the ion injection efficiency of analyte species. Consequently, analyte signal enhancement can be realized via extended ion accumulation times even though unwanted ions are present in overwhelming abundance. The TNT molecular anion signal obtained following a 1-s injection period is a factor of approximately 8 greater than that seen without the FNF; S[sub 2][sup [minus]] and S[sub 3][sup [minus]] cluster anion signals, obscured without the FNF due to matrix-ion-induced space charge effects, also are isolated completely via the FNF. The subsequent use of concatenated FNF waveforms to enhance detection specificity via MS/MS is also illustrated. The FNF-ion trap techniques described here should be generally applicable to many other ionization sources, whether of internal or external configuration. 37 refs., 6 figs., 1 tab.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7275099
• Journal Information: Analytical Chemistry (Washington); (United States), Journal Name: Analytical Chemistry (Washington); (United States) Vol. 66:3; ISSN 0003-2700; ISSN ANCHAM
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450100 -- Military Technology
Weaponry
& National Defense-- Chemical Explosions & Explosives
ANIONS
CHARGED PARTICLES
CHEMICAL ANALYSIS
CHEMICAL EXPLOSIVES
ELECTRIC DISCHARGES
ENERGY-LEVEL TRANSITIONS
EVAPORATION
EXCITATION
EXPLOSIVES
FLUIDS
GASES
GLOW DISCHARGES
ION SOURCES
IONIZATION
IONS
MASS SPECTROMETERS
MASS SPECTROSCOPY
MEASURING INSTRUMENTS
MULTIPOLES
NITRO COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHASE TRANSFORMATIONS
QUADRUPOLES
QUANTITATIVE CHEMICAL ANALYSIS
RESONANCE
SAMPLING
SIGNAL CONDITIONING
SPECTROMETERS
SPECTROSCOPY
TNT
TRAPPING
USES
VAPORS