US 6,051,436 AGranted

Method for the detection of nitro-containing compositions using ultraviolet photolysis

AssigneeLockheed Idaho Technologies Company

InventorsWilliam K. Reagen, Gregory D. Lancaster, Judy K. Partin, Glenn A. Moore

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Abstract

A method for detecting nitro-containing compositions (e.g. nitrate/nitrite materials) in water samples and on solid substrates. In a water sample, ultraviolet light is applied to the sample so that dissolved nitro compositions therein will photolytically dissociate into gaseous nitrogen oxides (NO.sub.2(g) and/or NO.sub.(g)). A carrier gas is then introduced into the sample to generate a gaseous stream which includes the carrier gas combined with any gaseous nitrogen oxides. The carrier gas is thereafter directed into a detector. To detect nitro-compositions on solid substrates, ultraviolet light is applied thereto. A detector is then used to detect any gaseous nitrogen oxides which are photolytically generated during ultraviolet illumination. An optional carrier gas may be applied to the substrate during illumination to produce a gaseous stream which includes the carrier gas and any gaseous nitrogen oxides. The gaseous stream is then supplied to the detector.

Claims2

Dependent claims

A method for analyzing a sample of solid material for the presence of nitro-containing compositions thereon, said method comprising the steps of:

providing an ultraviolet light source for generating ultraviolet light;
providing a sample of solid material comprising an uncovered and exposed surface, said uncovered and exposed surface allowing said ultraviolet light from said ultraviolet light source to be applied to said solid material without passing through any intervening structures;
positioning said ultraviolet light source directly above said uncovered and exposed surface of said solid material in order to create an uninterrupted gap between said solid material and said light source;
activating said ultraviolet light source so that said light source delivers said ultraviolet light into said gap and onto said uncovered and exposed surface of said solid material without interruption by any intervening structures, said ultraviolet light photolytically dissociating any of said nitro-containing compositions on said solid material into gaseous nitrogen oxides, said gaseous nitrogen oxides rising upwardly from said surface of said solid material;
providing gas detector means for detecting gaseous nitrogen oxides;
positioning at least a portion of said gas detector means above said uncovered and exposed surface of said solid material in order to create an uninterrupted gap between said solid material and said gas detector means so that any of said gaseous nitrogen oxides generated during delivery of said ultraviolet light onto said solid material will enter into said portion of said gas detector means without interruption by any intervening structures;
and
activating said gas detector means in order to determine if any of said gaseous nitrogen oxides were generated during delivery of said ultraviolet light onto said solid material.

5 more elements

A method for analyzing a sample of solid material for the presence of nitro-containing compositions thereon, said method comprising the steps of:

providing an ultraviolet light source for generating ultraviolet light;
providing a sample of solid material comprising an uncovered and exposed surface, said uncovered and exposed surface allowing said ultraviolet light from said ultraviolet light source to be applied to said solid material without passing through any intervening structures;
positioning said ultraviolet light source directly above said uncovered and exposed surface of said solid material in order to create an uninterrupted gap between said solid material and said light source;
activating said ultraviolet light source so that said light source delivers said ultraviolet light into said gap and onto said uncovered and exposed surface of said solid material without interruption by any intervening structures, said ultraviolet light photolytically dissociating any of said nitro-containing compositions on said solid material into gaseous nitrogen oxides, said gaseous nitrogen oxides rising upwardly from said surface of said solid material;
providing gas detector means for detecting gaseous nitrogen oxides;
passing a stream of at least one carrier gas over said surface of said solid material during delivery of said ultraviolet light onto said solid material, said carrier gas combining with any of said gaseous nitrogen oxides produced during delivery of said ultraviolet light in order to generate a gaseous stream which comprises said carrier gas in combination with said gaseous nitrogen oxides;
positioning at least a portion of said gas detector means above said uncovered and exposed surface of said solid material in order to create an uninterrupted gap between said solid material and said gas detector means so that said gaseous stream will enter into said portion of said gas detector means without interruption by any intervening structures;
and
activating said gas detector means in order to determine if any of said gaseous nitrogen oxides are present in said gaseous stream.

6 more elements

Dependencies are inferred from the claim text.