Method and composition for detecting oxidizing salts
AssigneeFLIR Systems, Inc.
InventorsLara Beth Wald, Gregory Charles Frye-Mason
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Abstract
The present invention provides methods for determining the presence of oxidizing salts. According to the current invention, analyte is collected on a swipe and subsequently heated to a temperature sufficient to release a detectable vapor phase component of the oxidizing salt. The vapor phase component passes reacts with a pH sensitive molecule. Reaction of the vapor phase product with the pH sensitive molecule produces a detectable change in response intensity.
Claims26
A method for determining the presence of an oxidizing salt comprising:
- collecting the oxidizing salt with a sampling material;
- presenting the sampling material to a sensor assembly, said sensor assembly including a solid substrate carrying a pH sensitive molecule, the pH sensitive molecule undergoing stimulation by an excitation source, said excitation source emitting light radiation at wavelengths between about 325 nm and about 700 nm, while monitoring the response of the pH sensitive molecule to the stimulation with a light sensor suitable for detecting changes in response intensity;
- heating the sampling material to a temperature sufficient to induce evaporative dissociation of the oxidizing salt thereby yielding evaporative dissociation compounds of the oxidizing salt;
- passing the evaporative dissociation compounds of the oxidizing salt into said sensor assembly and reacting said pH sensitive molecule with at least one dissociation compound;
- monitoring said pH sensitive molecule with said light sensor to determine any change in response intensity wherein a change in response intensity indicates the presence of oxidizing salt.
A method for determining the presence of oxidizing salt on a surface comprising:
- contacting a surface suspected of carrying an oxidizing salt selected from the group consisting of ammonium nitrate, urea nitrate, guanidine nitrate and ammonium perchlorate with a sampling material thereby collecting a sample from said surface;
- presenting the sampling material to a sensor assembly, said sensor assembly including a solid substrate carrying a pH sensitive molecule, the pH sensitive molecule undergoing stimulation by an excitation source, said excitation source emitting light radiation at wavelengths between about 325 nm and about 700 nm, while monitoring the response of the pH sensitive molecule to the stimulation with a light sensor suitable for detecting changes in response intensity;
- heating the sampling material to a temperature sufficient to induce evaporative dissociation of the oxidizing salt thereby yielding evaporative dissociation compounds of ammonium nitrate;
- passing the evaporative dissociation compounds into said sensor assembly and reacting said pH sensitive molecule with said dissociation compounds;
- monitoring said pH sensitive molecule with said light sensor for a change in response intensity thereby indicating the presence of an oxidizing salt on the sampled surface.
Dependencies are inferred from the claim text.