A detection kit for detecting combustion chamber leaks in water cooled otto or diesel vehicle engines includes a transparent solution reservoir placed in an expansion tank and/or expansion tank inlet/outlet hoses, and having low liquid and vapour permeability and high CO.sub.2 permeability, a pH indicator solution placed in the solution reservoir, stable under high temperature and high pressure, and indicating combustion chamber leaks by change of colour with the change in the pH value.

The present invention relates to a novel thieno[3,2-b]pyridine-5(4H)-one derivative compound, a preparation method thereof, and a use thereof. The novel thieno[3,2-b]pyridine-5(4H)-one derivative compound according to the present invention is synthesized via an aza-[3+3] cyclization addition reaction using BOP, wherein the compound is obtained by synthesizing a 4-arylthiophen-3-amine in which aryl groups such as 4-piperidyl-C6H4, 4-pyrrolidyl-C6H4, 4-MeOC6H4, 3,4,5-(MeO)3C6H4, C6H5, 4-C6H5C6H4, and 4-F3COC6H4 are introduced via a synthesis process by a bromination reaction, a hydrolysis reaction, a decarboxylation reaction, and a Suzuki coupling reaction of methyl 3-aminothiophene carboxylate, and by synthesizing 4-arylthiophen-3-amine and mono-methyl fumarate via a formal aza-[3+3] cyclization addition reaction using BOP and conjugation. Accordingly, novel thieno[3,2-b]pyridine-5(4H)-one derivative compounds according to the present invention have fluorescence properties with a wide range of emission wavelengths and thus may be utilized in various industrial fields such as physics, chemistry, and biomedical research.

Packaging materials may include a packaging material formed from an intelligent polymer composition, wherein the intelligent polymer composition includes a matrix polymer and an indicator, wherein the indicator triggers a color change in the intelligent polymeric composition when exposed to an external stimulus, and wherein the intelligent polymer composition is configured to contact a material enclosed within the packaging material. Methods may include forming a packaging material from an intelligent polymer composition, wherein the intelligent polymer composition includes a matrix polymer and an indicator, wherein the indicator triggers a color change in the intelligent polymeric composition when exposed to an external stimulus, and wherein the intelligent polymer composition is configured to contact a material enclosed within the packaging material.

Disclosed is a leaching solution composition for extracting available phosphate in soil, the composition including 100 parts by weight of a leaching solution containing acetic acid, lactic acid, ammonium fluoride, ammonium sulfate, and sodium hydroxide, of which the weights are 110% of the weights of constituent ingredients of a leaching solution for extracting available phosphate in soil, used in the Lancaster method and 0.001 parts by weight of a bromocresol green indicator.

The present disclosure relates to a fluorogenic pH-sensitive dye and a film for detecting pH using the fluorogenic pH-sensitive dye on a polymer film. The fluorogenic pH-sensitive dye includes an aryl compound having a sulfonyl group (—SO.sub.2) and an agarose compound covalently bonded to the sulfonyl group (—SO.sub.2) of the aryl compound.

The present disclosure relates to a device in particular, a sensor for determining a measurand correlated with a concentration of an analyte in a measuring medium, including a housing that has a region provided for contacting the measuring medium, a fluid line arranged in the housing, an interface that is arranged within the region provided for contacting the measuring medium and has a first side which is in contact with the fluid line and a second side which is in contact with an environment of the housing in particular, with the measuring medium in contact with the housing, a first reservoir that is arranged in the housing and fluidically connected to the fluid line and which contains a reagent intended for contacting and/or interacting with the analyte, and a transport mechanism that is designed to transport reagent from the first reservoir into the fluid line.

In this reagent composition for measuring the pH of test water, methyl red with an acid dissociation constant (pKa) of 5.1, phenol red with a pKa of 7.7 which is greater than that of methyl red, and bromocresol purple with a pKa of 6.3 which is between those of methyl red and phenol red are dissolved at prescribed ratios in a diol, such as ethylene glycol. With respect to test water to which the reagent composition has been added, absorbances at three wavelengths of a wavelength selected from a range of from 410 to 430 nm, a wavelength selected from a range of from 515 to 535 nm, and a wavelength selected from a range of from 580 to 600 nm are measured, and the pH of the test water is determined based on the absorbances. In this way, it is possible to measure the pH of the test water in a range of from 4 to 9.

An embodiment provides a method for measuring at least one characteristic of an aqueous sample, including: introducing an aqueous sample into a measurement device comprising one or more electrodes; oxidizing a transition metal to produce a higher valent metal by applying an electrical potential between an anode and a cathode of the measurement device; oxidizing, using the higher valent metal as a catalyst, a material within the aqueous sample; measuring a characteristic of the aqueous sample based upon the oxidized material, using a measurement device selected from the group consisting of: an electrochemical measurement device and an optical measurement device; and optimizing the electrical potential and at least one reagent delivered to the measurement device based on the measurement of the characteristic. Other aspects are described and claimed.

A device for detecting volatile compounds. The device includes a substrate and a matrix disposed on the substrate. The matrix includes a carboxyl-rich binder, a clay, and a pH-sensitive indicator dye admixed with the binder and the clay. The pH-sensitive indicator dye is dimensioned and configured to change color in response to contact with a pre-determined concentration of a volatile compound.

Disclosed are a selective colorimetric detection sensor and a colorimetric detection method for C.sup.6+ ions using size controlled label-free gold nanoparticles, which may be useful for the detection of toxic materials such as heavy metal ions in the environmental sector and the industry. Selective colorimetric sensor solution used therein is selectively reacted with only Cr.sup.6+ ions in trivalent chromium ions (Cr.sup.3+) and hexavalent chromium ions (Cr.sup.6+), and there is no interference effect resulting from other metal ions, and it is possible to very rapidly and precisely detect Cr.sup.6+ ions compared to the related art.