The method and kit for detecting technetium-99m radioisotopes provide color-change solutions for visual detection of technetium-99m radioisotope-based tracers. A first color-change solution is formed from a mixture of thymol blue sodium salt solution and bromocresol purple solution. A first sample to be tested is determined to be a substance containing technetium-99m radioisotopes when the first sample to be tested turns yellow in color following spraying with the first color-change solution. A second color-change solution is formed from a mixture of bromocresol green solution and neutral red solution. A second sample to be tested is determined to be a substance containing technetium-99m radioisotopes when the second sample to be tested turns purple in color following spraying with the second color-change solution. The method and kit provide a rapid test for distinguishing a spill of radioactive TC-99m tracer from a saline spill in a nuclear medicine facility.

The present invention provides a method for preparing a polyion thin film (in particular a polyion thin film with different surface morphologies) and the polyion thin film prepared by the method. The method comprises: providing a substrate, and coating a first lubricant on a surface of the substrate or on a surface of a tinfoil covered on the surface of the substrate; covering a film-forming liquid of the polyion thin film on the surface of the substrate with the first lubricant, and after coating uniformly, covering a cover plate coated with a second lubricant on the film-forming liquid; performing a polymerization reaction of ionic liquid monomers in the film-forming liquid to form a polyion thin film; and separating the polyion thin film and cleaning it to obtain the polyion thin film. The polyion thin films with different surface morphology can be prepared. The present invention further provides a detection kit.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

Chemical sensors and methods of forming and making the same include an input terminal and an output terminal. A negative capacitance structure is configured to control a current passing horizontally from the input terminal to the output terminal, and has a first and second metal layer that are arranged vertically with respect to one another, and a ferroelectric layer positioned between the first and second metal layers. An electrode is in electrical contact with the negative capacitance structure, and is configured to change potential, to exceed a threshold, thereby triggering a discontinuous polarization change in the negative capacitance structure.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

A composition and method for the photometric determination of a film-forming amine in liquid by adding an indicator reagent to an aqueous system that is pH dependent, combining a water soluble non-ionic polymer to modify the physical properties of the aqueous system, and adding an acidic buffer to said aqueous system to lower pH and activate said indicator, said water soluble polymer keeping the filming amine/indicator complex in solution despite the acidic buffer and preventing it from precipitating out.

A medical instrument processor includes an enclosure, a liquid distribution system, and a disinfectant concentration measuring subsystem. The enclosure is configured to hold a medical instrument. The liquid distribution system is configured to deliver a disinfection solution to a medical instrument within the enclosure. The liquid distribution system has a liquid outlet. The disinfectant concentration measuring subsystem includes a first mixing chamber in fluid communication with the liquid outlet, a pump that is configured to simultaneously pump the disinfection solution and the reagent solution into the first mixing chamber, and a concentration analysis assembly that is operable to determine a concentration of disinfectant in a sample solution that is output from the first mixing chamber. The reservoir is in fluid communication with the first mixing chamber.

Methods for determining the acidity of an acidic aqueous solution. These methods make it possible to measure the total acidity of an aqueous solution comprising a strong acid or a mixture of strong acids and, if this solution contains one or more hydrolysable cations, to also measure its free acidity.

The invention provides a method for determining the antioxidant capacity of beverage by titrating a standard oxidant solution using liquid sample of the beverage and monitoring oxidation reduction potential of the solution until a neutral reference value is reached, and using the titration volume to calculate the antioxidant capacity. The invention also provides test apparatus and test kit for performing the method of the invention.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.