Method and kit for detecting explosive substances containing certain oxidants
Inventors
Assignees
Publication Number
US-7846740-B2
Publication Date
2010-12-07
Expiration Date
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Abstract
The invention relates to a method for detecting an explosive substance which contains chlorate, bromate and/or organic peroxide, wherein a suspect substance is contacted with a first reagent, which is a strongly acid solution of at least one primary or secondary aromatic amine, whereby chlorate or bromate type explosive affords a distinct coloration; and in the absence of such coloration, contacting the same sample (in contact with the first reagent) with a second reagent, which is a solution comprising cations of at least one transition metal, whereby the presence of organic peroxides in the sample, which has been hydrolyzed at least partly to hydrogen peroxide by the strong acid of the first reagent, affords a distinct coloration. The invention further relates to a kit containing separate first and second reagents; a container of mixed reagents for detecting peroxide; and a kit including such container.
Core Innovation
The invention provides a method for detecting an explosive substance which contains an oxidant selected from chlorate, bromate and organic peroxide, comprising sequential steps of contacting a sample with a first reagent which is a strongly acidic solution of at least one primary or secondary aromatic amine whereby the presence of a chlorate or bromate type explosive affords a distinct coloration, and in the absence of such coloration contacting the same sample, already in contact with the first reagent, with a second reagent which is a solution comprising cations of at least one transition metal whereby organic peroxides in the sample, which has been hydrolyzed at least partly to hydrogen peroxide by the strong acid of the first reagent, affords a distinct coloration. This sequential testing permits testing for chlorates or bromates first and then for organic peroxides on the same sample.
The invention further provides test kits and reagent kits corresponding to the sequential method, including a kit comprising a first container with the strongly acidic aromatic amine solution and a second container with the transition metal cation solution, and a reagent kit comprising a container of reagent which is a solution comprising cations of at least one transition metal together with instructions for use after at least partial acid hydrolysis of an organic peroxide to hydrogen peroxide. The invention also describes preferred features such as inclusion of water-miscible non-aqueous solvents, use of a diarylamine (for example diphenylamine), sulfuric acid as the strong acid, transition metals including iron and others, dispensing devices, and an absorbent medium for sampling suspected sources.
Claims Coverage
The patent includes two independent claims, covering a sequential detection method and a test kit; the following inventive features summarize the main elements recited in those independent claims.
Sequential detection method for chlorate, bromate and organic peroxide
Providing a sample of suspect explosive substance; contacting the sample with a first reagent which is a strongly acidic solution of at least one primary or secondary aromatic amine whereby the presence of a chlorate or bromate type explosive affords a distinct coloration; and in the absence of such coloration, contacting the same sample, already in contact with the first reagent, with a second reagent which is a solution comprising cations of at least one transition metal, whereby the presence of organic peroxides in the sample, which has been hydrolyzed at least partly to hydrogen peroxide by the strong acid of the first reagent, affords a distinct coloration.
Test kit comprising first and second reagent containers for oxidant detection
A kit comprising a first container including therein a first reagent which is a strongly acidic solution of at least one primary or secondary aromatic amine, and a second container including therein a second reagent which is a solution comprising cations of at least one transition metal, further characterized by features including inclusion of at least one water-miscible non-aqueous solvent, the aromatic amine comprising a carbocyclic aromatic amine, the strongly acidic solution comprising sulfuric acid, the transition metal selected from iron, copper, manganese, chromium, cobalt and ruthenium, at least one device for dispensing reagents, an absorbent medium for sampling suspected sources, and optionally at least one container of reagent for testing for nitroaromatics, organic nitrates, nitramines and inorganic nitrates.
The independent claims cover a sequential two-reagent detection method that first detects chlorate/bromate with a strongly acidic aromatic amine reagent and then detects organic peroxides by applying a transition-metal cation reagent to the same sample after partial acid hydrolysis, and a corresponding kit comprising separate containers for those reagents with preferred compositional and accessory features.
Stated Advantages
Enables detection of explosives containing chlorates or bromates and sequential detection of peroxide-based explosives after testing for chlorates or bromates in the same sample.
Improves detection capability by using only one collecting medium for both tests carried out sequentially.
Use of diphenylamine is described as much less toxic and more sensitive for present purposes than aniline.
Reagents are described as very stable under exposure to light and normal conditions, with ampoules not needing to be colored.
Reagents are described as having high sensitivity (for example, reagent A gives a deep blue coloration with chlorates or bromates within seconds and is sensitive to very small amounts).
Documented Applications
Detecting an explosive substance which contains an oxidant selected from chlorate, bromate and organic peroxide.
A test kit for use in detecting an explosive substance in a suspect sample which contains an oxidant selected from chlorate, bromate and organic peroxide.
A reagent kit comprising a container of a transition-metal cation solution for detecting organic peroxide after at least partial acid hydrolysis to hydrogen peroxide.
Sampling a suspected source for explosives where the suspected source includes a substance, a surface of an inanimate object and an exterior periphery of a human.
In absence of positive coloration for chlorate, bromate or peroxide, providing a second sample of the suspect substance and testing it for nitroaromatics, organic nitrates, nitramines and inorganic nitrates.
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