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Reagent assessment for detection of ammonium ion-molecule complexes

Published in:
Rapid Commun. Mass Spectrom., Vol. 27, 2013, pp. 2797-2806.

Summary

An MS-based framework was developed to quantitatively assess API ion-molecule reagent chemistries based on ammonium selectivity versus competing ions, and intrinsic ammonium binding strength and complex survivability for detection. Methyl acetoacetate is an attractive ammonium reagent for vapor-phase API techniques given its high vapor pressure, preferential selectivity, and high critical energy for dissociation.
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Summary

An MS-based framework was developed to quantitatively assess API ion-molecule reagent chemistries based on ammonium selectivity versus competing ions, and intrinsic ammonium binding strength and complex survivability for detection. Methyl acetoacetate is an attractive ammonium reagent for vapor-phase API techniques given its high vapor pressure, preferential selectivity, and high critical...

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Measurement of trace explosive residues in a surrogate operational environment: implications for tactical use of chemical sensing in C-IED operations

Published in:
26th Army Science Conf., 1 December 2008 (Anal. Bioanal. Chem., Vol. 395, pp. 357-369).

Summary

A campaign to measure the amount of trace explosive residues in an operational military environment was conducted on May 27?31, 2007, at the National Training Center at Fort Irwin, CA, USA. The objectives of this campaign were to develop the methods needed to collect and analyze samples from tactical military settings, to use the data obtained to determine what the trace explosive signatures suggest about the potential capabilities of chemical-based means to detect IEDs, and, finally, to present a framework whereby a sound understanding of the signature science can be used to guide development of new sensing technologies and sensor concepts of operation. Through our use of combined background and threat signature data, we have performed statistical analyses to estimate upper limits of notional sensor performance that is limited only by the spatial correlation of the signature chemicals to the threats of interest.
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Summary

A campaign to measure the amount of trace explosive residues in an operational military environment was conducted on May 27?31, 2007, at the National Training Center at Fort Irwin, CA, USA. The objectives of this campaign were to develop the methods needed to collect and analyze samples from tactical military...

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Detection of condensed-phase explosives via laser-induced vaporization, photodissociation, and resonant excitation

Published in:
Appl. Opt., Vol. 47, No. 31, 1 November 2008, pp. 5767-5776.

Summary

We investigate the remote detection of explosives via a technique that vaporizes and photodissociates the condensed-phase material and detects the resulting vibrationally excited NO fragments via laser-induced fluorescence. The technique utilizes a single 7 ns pulse of a tunable laser near 236:2nm to perform these multiple processes. The resulting blue-shifted fluorescence (226 nm) is detected using a photomultiplier and narrowband filter that strongly block the scatter of the pump laser off the solid media while passing the shorter wavelength photons. Various nitro-bearing compounds, including 2,6-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX) were detected with a signal-to-noise of 25 dB. The effects of laser fluence, wavelength, and sample morphology were examined.
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Summary

We investigate the remote detection of explosives via a technique that vaporizes and photodissociates the condensed-phase material and detects the resulting vibrationally excited NO fragments via laser-induced fluorescence. The technique utilizes a single 7 ns pulse of a tunable laser near 236:2nm to perform these multiple processes. The resulting blue-shifted...

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