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 method is provided for producing a visual hydrogen sensor and to a sensor produced in this manner, the sensor allowing the presence of hydrogen gas in a medium to be detected by the naked eye as a result of a change of color in the sensor. The method involves the deposition of thin porous layers of oxides that do not absorb visible light in their completely oxidized state which become colored when they are partially reduced. This deposition is carried out using vapor phase deposition (PVD) in a glancing angle configuration (GLAD). The method also involves the preparation of a solution of an active metal precursor capable of dissociating the hydrogen molecule and a carrier vector and the deposition of this solution on the oxide layer in order to incorporate a minimum quantity of active metal within the pores of the oxide layer in the form of nanoparticles.

A microfluidic device for measuring an amount of an oxidant in a solution is disclosed. The device includes a microfluidic substrate configured to mix a solution sample to be analysed with an indicator dye solution containing an indicator dye under conditions suitable for some of the indicator dye to react with any oxidant in the solution to produce an oxidant measurement solution having a reduced indicator dye concentration that is indicative of the amount of oxidant in the solution, the microfluidic substrate including an optical reading window through which the reduced indicator dye concentration in the oxidant measurement solution can be measured optically.

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.

Disclosed are a hydrogen detection sensor and a method of manufacturing the same. The hydrogen detection sensor is manufactured by using hydrothermal synthesis method to synthesize a molybdenum oxide (MoO.sub.3) nanostructure, and irradiating UV light thereon to form an MoO.sub.3Pd nanocomposite comprising the molybdenum oxide nanostructure with palladium (Pd) catalyst particles, and coating the MoO.sub.3Pd nanocomposite on a substrate. As such, a visible color change from the MoO.sub.3 before and after exposure to hydrogen may be so obvious that the sensing or sensitivity of hydrogen and the long-term stability may be substantially improved. In addition, the manufacturing process is simple, and the manufacturing costs may be reduced.

The present invention relates to a monoazo-based dye for acid detection, which changes color upon addition of or exposure to acid and, more specifically, to a dye which changes color within a few seconds upon exposure to a trace amount of a strong acidic material, and a fiber product using the same. The monoazo-based dye for acid detection according to the present invention has an effect of reacting with a trace amount of strong acid to change color, and returning to the original color when the acid is removed. Also, a fiber dyed with the dye of the present invention exhibits high color fastness and thus is not discolored and faded by laundering or sunlight. In addition, there is an effect of preventing secondary contamination at an accident scene and serious accidents from harmful environmental factors, when protective or working clothes are manufactured applying the effect, thereby providing a function enabling workers to recognize an exposure to acid in real time in the case of an exposure to an acid-contaminated environment.

Provided is an optical detection chip that makes it possible to accurately measure, in a short time, hydrogen sulfide and methyl mercaptan contained in a gas subject to detection. An optical detection chip is provided with: an optically transparent substrate; and a layer structure provided with a pigment layer that is formed on the optically transparent substrate, that includes organic pigment molecules containing amino groups, ketone groups, or quinones, as well as metal ions of at least one kind selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, Ag, Pb, and Tl, and that exhibits a color change in response to a gas subject to detection including at least one of hydrogen sulfide and methyl mercaptan.

a gas detecting device has a gas detecting region on a detection card. A window extends over the detecting region, protecting it from ultraviolet light. The window includes air inlets that allow air to travel underneath the window and interact with the detecting region. Filters block or remove any contaminants in the air prior to the air interacting with the detecting region. As a result, false positives are minimized and the functional lifespan of the detecting device is extended.

Aromatic diimide chromophores and methods for using the chromophores for the detection of volatile organic compounds are described. The chromophores are able to reversibly change colors in the presence or absence of volatile organic compounds.

Monolithic nanoporous material, which is self-standing (i.e. self-supported or cohesive), solid and transparent, essentially devoid of cracks, transparent to UV radiation, obtained by the Sol-Gel process, the material having a basic nature and including a reagent capable of generating a stained product by forming a bond with phenol, a basic compound or mixture of basic compounds and a compound or mixture of oxidant compounds, method for preparation and use in the detection and in the selective depollution of phenol or one of its derivatives.