The present invention provides a method for measuring the gastric acidity of a mammal using a .sup.13C-labeled carbonate compound. Specifically, the present invention relates to a method for measuring the gastric acidity of a mammal including the following steps:

(1) using, as a test sample, expired air of a mammalian subject excreted at any point in time within 30 minutes after oral administration of a predetermined amount of a .sup.13C-labeled carbonate compound, measuring behavior of .sup.13CO.sub.2 in the expired air;

(2) comparing the behavior of .sup.13CO.sub.2 (measured .sup.13CO.sub.2 behavior) obtained in step (1) with the behavior of corresponding .sup.13CO.sub.2 (reference .sup.13CO.sub.2 behavior) that has been obtained beforehand in a control mammal; and

(3) determining the gastric acidity of the mammalian subject based on a difference between the reference .sup.13CO.sub.2 behavior and the measured .sup.13CO.sub.2 behavior obtained above.

Provided herein are pharmaceutically acceptable sodium nitrite and pharmaceutical compositions thereof. Also provided herein are methods for determining the total non-volatile organic carbon in a sodium nitrite-containing sample. Further provided herein are methods for producing pharmaceutically acceptable sodium nitrite. Still further provided herein are methods of treatment comprising the administration of pharmaceutically acceptable sodium nitrite.

According to embodiments of the present application, a carbon dioxide sensing color changeable dye can comprise a carbon dioxide status indicator, a solvent, a polymer wherein the carbon dioxide status indicator is dispersed, an optional plasticizer, and an optional agent to facilitate mixing. The color changeable dye is a first color in the presence of a carbon dioxide rich environment and is capable of changing to a second color upon exposure to atmospheric condition for a period of time corresponding to the intended use time of a restricted, disposable or limited use product. Methods of making and using the color changeable dye and apparatuses incorporating such dye are also disclosed.

A method for determining the total organic carbon in a sample which includes mixing the sample with a reagent containing at least one acid effective for reacting with inorganic carbon-containing materials in the sample, and at least one oxidizing agent effective for oxidizing organic carbon-containing materials in the sample in the presence of ultraviolet radiation, and detecting the carbon dioxide generated, is described. The at least one acid may include phosphoric acid, while the oxidizing agent may include sodium persulfate. In accordance with an embodiment of the inventive concept, the sample is first injected into a reaction chamber, which is continuously flushed with carbon dioxide free gas with no UV light present, and CO.sub.2 generated from any inorganic carbon in the sample as carbonates is flowed through the detector, and may be recorded. Subsequent to this step, the UV light is passed through the reaction chamber and CO.sub.2 generated from the reaction of the at least one oxidizing agent with the organic material in the solution in the presence of ultraviolet radiation, is flowed through the detector, which may be a non-dispersive infrared detector, after the reaction chamber is sparged using a carbon dioxide free gas, and recorded.

A method uses an Dioleoylphosphatidylcholine (DOPC) surfactant based bio film that reacts with a material in a known manner, and a device that utilizes such a biofilm, to detect material of interest is provided. The principles of the present invention are particularly useful in detecting/measuring a material.

Technologies are generally described for gas filtration and detection devices. Example devices may include a graphene membrane and a sensing device. The graphene membrane may be perforated with a plurality of discrete pores having a size-selective to enable one or more molecules to pass through the pores. A sensing device may be attached to a supporting permeable substrate and coupled with the graphene membrane. A fluid mixture including two or more molecules may be exposed to the graphene membrane. Molecules having a smaller diameter than the discrete pores may be directed through the graphene pores, and may be detected by the sensing device. Molecules having a larger size than the discrete pores may be prevented from crossing the graphene membrane. The sensing device may be configured to identify a presence of a selected molecule within the mixture without interference from contaminating factors.

This invention relates to the preparation of N-(phosphonomethyl)glycine (“glyphosate”) from N-(phosphonomethyl)iminodiacetic acid (“PMIDA”), and more particularly to methods for control of the conversion of PMIDA, for the identification of reaction end points relating to PMIDA conversion and the preparation of glyphosate products having controlled PMIDA content.

Provided herein are pharmaceutically acceptable sodium nitrite and pharmaceutical compositions thereof. Also provided herein are methods for determining the total non-volatile organic carbon in a sodium nitrite-containing sample. Further provided herein are methods for producing pharmaceutically acceptable sodium nitrite. Still further provided herein are methods of treatment comprising the administration of pharmaceutically acceptable sodium nitrite.

According to embodiments of the present application, a carbon dioxide sensing color changeable dye can comprise a carbon dioxide status indicator, a solvent, a polymer wherein the carbon dioxide status indicator is dispersed, an optional plasticizer, and an optional agent to facilitate mixing. The color changeable dye is a first color in the presence of a carbon dioxide rich environment and is capable of changing to a second color upon exposure to atmospheric condition for a period of time corresponding to the intended use time of a restricted, disposable or limited use product. Methods of making and using the color changeable dye and apparatuses incorporating such dye are also disclosed.

This invention relates to the preparation of N-(phosphonomethyl)glycine (“glyphosate”) from N-(phosphonomethyl)iminodiacetic acid (“PMIDA”), and more particularly to methods for control of the conversion of PMIDA, for the identification of reaction end points relating to PMIDA conversion and the preparation of glyphosate products having controlled PMIDA content.