A composition and an assay solution for the determination of dissolved borate concentration comprising a catechol dye, a solubilizing agent, and a buffer are described. The composition and assay solution may further comprise a solubilizing agent. The catechol dye acts as a chemical borate sensor. The chemical borate sensor changes its optical properties upon binding to borate. The multivalent cation chelator binds multivalent cations present in a sample being analyzed. The buffer prevents changes in pH. The solubilizing agent aids in solubilizing the catechol dye, multivalent cation chelator, and/or the buffer.

A composition and an assay solution for the determination of dissolved borate concentration comprising a catechol dye, a solubilizing agent, and a buffer are described. The composition and assay solution may further comprise a solubilizing agent. The catechol dye acts as a chemical borate sensor. The chemical borate sensor changes its optical properties upon binding to borate. The multivalent cation chelator binds multivalent cations present in a sample being analyzed. The buffer prevents changes in pH. The solubilizing agent aids in solubilizing the catechol dye, multivalent cation chelator, and/or the buffer.

A test strip includes a substantially transparent substrate and one or more colorimetric test spots on the transparent substrate. Each colorimetric test spot has one or more sensing chemicals chemically attached onto a porous support material. The porous support material has at least one exposed surface configured to absorb a body fluid. The one or more sensing chemicals are configured to change a color in response to a presence of a target drug in the body fluid.

The present invention relates to a two-photon fluorescent probe compound represented by Chemical Formula 1 below, and a method for imaging amyloid beta plaques using same, wherein the two-photon fluorescent probe compound according to the present invention maintains an excellent two-photon fluorescence cross-section while at the same time maintaining efficient BBB permeability by minimizing background fluorescence such that a high signal-to-noise ratio is exhibited, and can effectively image Aβ plaques since high selectivity and sensitivity to Aβ plaques are exhibited, and can thus be usefully used in the field of neurodegenerative disease research, including early diagnosis and treatment of Alzheimer's disease. [Chemical Formula 1]

The invention provides a mild procedure for the functionalization of cellulose and other substrates with a detection reagent such as N-(1-naphthyl)ethylenediamine and is able to achieve much higher functionalization density than previously reported. A paper-based device created using cellulose functionalized according to the invention allowed for much lower detection limits for nitrite in various kinds of water samples than have been seen using paper-based devices. In addition, grafting of N-(1-naphthyl)ethylenediamine to cellulose improved the stability of the N-(1-naphthyl)ethylenediamine in the presence of moisture and light.

A visually sensible indicator of temperature including electronic temperature sensing circuitry sensing at least when a temperature exceeds at least one predetermined temperature threshold and providing at least one corresponding threshold exceedance output which is sensible as heat and a heat-responsive visually sensible display which is responsive to the at least one threshold exceedance output for providing at least one visually sensible indication indicating that the temperature has exceeded the predetermined temperature threshold.

Water-based formulations comprising an indicating composition dispersed in water are described. The water-based indicating compositions include an organic Bi(III) compound, a sulfur source, a carbonate salt, and strontium hydroxide. Formulations further including a resin and/or an acidic additive are also described.

The instant application pertains to a process for improving or managing the recycling of monoethylene glycol from an oil and gas operation with more efficient and cost-effective monitoring. The process comprises repeatedly testing an aqueous solution comprising monoethylene glycol using a test strip to obtain results for various known parameters. The results can be calibrated versus the known parameters to determine an adjustment to the test strip result.

An apparatus for in-line monitoring of nitrite content in a metalworking fluid is provided, the apparatus comprising a sample inlet for receiving a sample of a metalworking fluid, a dilution inlet for receiving a dilution fluid, a reagent inlet for receiving a photoactive reagent, a reaction volume for containing a sample mixture in fluid communication with the sample inlet, dilution inlet and reagent inlet, a photometer for monitoring the sample mixture, and a flow control system for controlling fluid flow in the apparatus, to: selectively introduce the sample, the dilution fluid and/or the photoactive reagent from the respective inlets to the reaction volume to form the sample mixture, retain the sample mixture in the reaction volume and discharge the sample mixture from the reaction volume.

The present disclosure provides a detection method of wormlike micelles, and belongs to the technical field of analytical chemistry. In the present disclosure, z-ArN.sub.2.sup.+ is used as a chemical probe substance; a long-chain probe is added to a test solution for probing an interfacial region, and a short-chain probe is added to a surfactant-free control solution. A selectivity of the probe with different nucleophiles is determined by the above method, and a yield of an obtained product is measured by high-performance liquid chromatography (HPLC); and the wormlike micelles are detected by measuring the yield of the product using the selectivity of the short-chain probe to be converted into an interfacial mole number. The wormlike micelles are detected by chemical probes, and the chemical probes have a simple preparation method, a low cost, real-time detection, and broad prospects for use.