Application of laser photofragmentation-resonance enhanced multiphoton ionization to ion mobility spectrometry
We demonstrate detection of nitro-containing compounds with laser photofragmentation (PF) coupled with resonance enhanced multiphoton ionization (REMPI) and ion mobility spectrometry (IMS). In PF-REMPI, a laser dissociates the parent molecules, producing fragments that can then be ionized by absorption of additional laser photons. The production of these ions strongly depends on the wavelength of laser light, with ion yields corresponding to the absorption spectrum of the fragments [nitric oxide (NO) in the present case]. Combining IMS with PF-REMPI provides further specificity, separating ions according to their mobilities through an atmospheric-pressure drift tube. In this work, we use a pulsed UV laser to examine the characteristics of atmospheric-pressure PF-REMPI, the chemistry occurring in the ionization region and drift tube, and the viability of detecting ions created by both resonance-enhanced and nonresonant ionization. Probing NO in a helium-nitrogen bath, we demonstrate that the detection of ions displays single-shot response to changes in ion generation, with an ion extraction-to-collection efficiency of {approx}12%. We then evaluate the sensitivity and specificity of PF-REMPI/IMS as applied to the detection of both the explosive surrogate 2, 4-dinitrotoluene and the nuisance compound nitrobenzene.
- OSTI ID:
- 22036459
- Journal Information:
- Applied Optics, Journal Name: Applied Optics Journal Issue: 11 Vol. 49; ISSN 0003-6935; ISSN APOPAI
- Country of Publication:
- United States
- Language:
- English
Similar Records
Direct detection of atomic ions from molecular photofragmentation during nonresonant multiphoton ionization of sputtered species
Photofragmentation approaches for the detection of polyatomic molecules.
Resonant multiphoton ionization spectra of molecules and molecular fragments. Technical report, October 1987--September 1988
Technical Report
·
Wed Sep 01 00:00:00 EDT 1993
·
OSTI ID:10184330
Photofragmentation approaches for the detection of polyatomic molecules.
Conference
·
Sat May 01 00:00:00 EDT 2010
·
OSTI ID:1016989
Resonant multiphoton ionization spectra of molecules and molecular fragments. Technical report, October 1987--September 1988
Technical Report
·
Tue Jul 01 00:00:00 EDT 1997
·
OSTI ID:503462