Joint detection of surface traces of nitroand organophosphorus compounds
S.M. Bobrovnikov1,2, E.V. Gorlov1,2, V.I. Zharkov1, S.N. Murashko1,2
1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
2National Research Tomsk State University, Tomsk, Russia
Keywords: nitrocompound, organophosphorus compound, trace, laser fragmentation, nitric oxide, NO-fragment, phosphorus oxide, PO-fragment, laser-induced fluorescence
Abstract
This work continues the study of the possibility of using the laser fragmentation/laser-induced fluorescence (LF/LIF) method for the remote detection of nitrocompounds (NC) and organophosphorus compounds (OPC). A method for the combined detection of surface traces of NС and OPС is discussed. It is experimentally shown that exciting laser radiation wavelength of 246.824 nm, falling in the region of overlapping rotational lines of γ(0, 2) and γ(0, 0) bands of NO and PO absorption spectra, can be used for the simultaneous excitation of fluorescence of NС and OPС photofragments. To improve the noise immunity of the LF/LIF detection method, it is proposed to use a wavelength of the probing laser radiation in the range of overlapping γ(0, 2) and γ(1, 1) bands of the absorption spectra of NO- and PO-fragments in excited vibrational states after fragmentation. The resulting intense anti-Stokes γ(0, 1) and γ(1, 0) fluorescence bands are located in the spectral range 235-240 nm and do not overlap with the spectra of broadband Stokes fluorescence of surface materials bearing traces of NС and OPСs. The results can be used in the development of a universal system for the simultaneous detection of surface traces of explosives and toxic substances by LF/LIF method.
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