A formaldehyde detecting device includes a formaldehyde detecting unit which includes a formaldehyde detecting layer, a diffusion restricting member and a concentration indicator. The formaldehyde detecting layer includes a formaldehyde detecting material that develops color when reacting with formaldehyde. The diffusion restricting member is disposed on the formaldehyde detecting layer and permits a restricted amount of formaldehyde to pass therethrough to react with the formaldehyde detecting material. Concentration of formaldehyde is determined based on a color change on the formaldehyde detecting layer, and is indicated by the concentration indicator.

Apparatuses, systems, and methods for detecting and monitoring hydrogen sulfide in a natural gas stream are disclosed herein. The apparatuses typically include a body comprising at least a first wall, a second wall spaced from the first wall, and a third wall coupled to the first wall and the second wall, wherein the first wall, the second wall, and the third wall define a chamber. The apparatus also typically includes an inlet conduit configured to receive a gaseous stream comprising natural gas and provide the gaseous stream to the chamber; a pressure valve coupled to the exit port, the pressure valve being configured to actuate to release an amount of gas; and an indicator at least partially disposed in the chamber, wherein the indicator comprises a reactive material that is adapted to produce a visual change in the presence of hydrogen sulfide.

A gas detection element for detection of a measurement target gas is provided. The gas detection element includes a gas detection layer including a chemochromic pigment; and a spacer. The spacer is permeable to the measurement target gas, is disposed on a first surface of the gas detection layer, and has an area smaller than an area of the gas detection layer.

The present invention is related to the detection of formaldehyde concentrations in the air by using a coordination polymer, which comprises repeating coordination complexes with an octahedral geometry, wherein said coordination complex comprises iron (II), at least one ligand comprising an amino moiety; wherein the coordination polymer further comprises counter-ions; for the identification and/or quantification of formaldehyde.

An embodiment provides a method for measuring total chlorine in a solution, including: preparing a thiocarbamate indicator; introducing the thiocarbamate indicator to a solution, wherein the solution contains an amount of monochloramine; adding an additive to the solution, wherein the additive accelerates the reaction rate between the thiocarbamate indicator and monochloramine and causes a change in fluorescence of the solution; and measuring the amount of monochloramine in the solution by measuring an intensity of the fluorescence. Other aspects are described and claimed.

A carbon dioxide detector includes a carrier impregnated with an ink composition containing a pH indicator, an alkaline agent, a water retention agent, and water, and has a water content of 30 to 40 mass %.

An embodiment provides a method for measuring total chlorine in a solution, including: preparing a thiocarbamate indicator; introducing the thiocarbamate indicator to a solution, wherein the solution contains an amount of monochloramine; adding an additive to the solution, wherein the additive accelerates the reaction rate between the thiocarbamate indicator and monochloramine and causes a change in fluorescence of the solution; and measuring the amount of monochloramine in the solution by measuring an intensity of the fluorescence. Other aspects are described and claimed.

A liquid reagent composition for detecting phenol or phenol derivatives includes a reagent capable of generating a stained product by forming a bond with phenol, an oxidant compound or mixture of oxidant compounds, a basic compound or mixture of basic compounds. The ratio of [stained reagent]:[oxidant compound] is 1:2 to 50:1, having a pH greater than 7. Also disclosed is a kit for the use of the composition and liquid-phase method for analysing a fluid potentially containing phenol or a phenol derivatives.

The present disclosure is directed to methods and systems for detecting a chemical substance. The methods and systems include using gas-solid phase chemistry to chemically and/or physically modify a substance of interest so that the substance can be vaporized and detected through an analysis of the substance.

Systems and methods are provided for tracking all chemicals, including odors, a package is exposed to throughout the shipping process. A device is attached to the package or placed within the package to extract the chemicals that are in the surrounding environment to the device. The device can extract and concentrate volatile, semi-volatile and non-volatile chemicals that the device and the corresponding package are exposed to throughout the shipping process. The extracted chemicals may then be desorbed from the device and analyzed by an analytical instrumentation method.