Abstract: 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.

Abstract: The present disclosure relates to an optochemical sensor element comprising: a substrate layer having a first substrate side facing toward a measurement medium and an opposite second substrate side; a functional layer, on the first substrate side and having a first reference dye, an indicator dye, and a second reference dye, wherein the first reference dye comprises an inorganic material, is insensitive to pH, and is suitable to emit a first luminescence signal upon stimulation, wherein the indicator dye comprises an organic material and is sensitive to pH, and is suitable to emit a third luminescence signal upon stimulation, wherein the second reference dye comprises an organic material, is insensitive to pH, and has a passivated functional group, and is suitable to emit a second luminescence signal upon stimulation, wherein the substrate layer is transparent to the stimulation signal and the luminescence signals.

Abstract: A microfluidic device includes a microchannel, which defines a flow path for a liquid. It further includes a liquid-pinning trench, which is arranged so as to form an opening that extends across the flow path. In addition, the device includes an electrode extending across the flow path so as to at least partly overlap the trench. The trench and overlapping electrode make up an electrowetting gate, which allows an efficient, reliable, and easy-to-implement flow control mechanism. In addition, such a mechanism requires relatively low actuation voltages (less than 10 V) to resume the liquid flow. Thus, a microfluidic chip having gates such as described herein can be controlled with a portable system, e.g., a smartphone connectivity. The present devices may notably be embodied as point-of-care diagnostic devices. Related devices, as well as methods of operation and methods of fabrication of such devices, are also disclosed.

Abstract: The present invention provides derivatized indicator compounds, such as pH indicator compounds, which can be covalently immobilized to a variety of solid substrates to produce an indicator pad. Such pads can be used to monitor water quality in variety of settings. In particular, the pads of the invention are useful in devices which monitor the quality of recreational water, such as water in swimming pools, hot tubs, and amusement park attractions, including water slides, and water-based rides. The present invention overcomes the limitations of commercially available pad chemistries.

Abstract: A flow cytometer capable of easily and reliably providing flow cytometry results without requiring a special trained technician is provided. The flow cytometer 10 includes an input unit 60 that receives an input of information for specifying a measurement item, a condition selection unit 71 for selecting a measurement condition from among one or a plurality of measurement conditions corresponding to information for specifying the measurement item received by the input unit 60, and a measurement unit 65 having a flow cell 20 through which a particle-containing liquid containing particles in the sample passes, wherein the measurement unit 65 optically measures particles of the particle-containing liquid flowing through the flow cell 20 in accordance with the measurement condition selected by the condition selection unit 71.

Abstract: The present disclosure relates to a composition for cell imaging including a probe compound, and a method of cell-material imaging using the same. The composition for cell imaging and the method of cell-material imaging are provided to image the material in the cell by measuring fluorescence generated by reacting the probe and a material in a cell.

Abstract: The present disclosure provides methods for identifying a hydrocarbon fuel, such as the presence and/or amounts of marker compounds having a fluorescence intensity and, through correlation, the presence and/or amounts of additive package(s) within the hydrocarbon fuel. The methods include obtaining a sample of a hydrocarbon fuel including a marker compound having fluorescence, combining the hydrocarbon fuel with water, and subjecting a water phase thereof to light for observing fluorescence.

Abstract: An embodiment provides a method for deriving an amount of PFAS substances from a total organic fluoride measurement in a sample, including: removing inorganic fluoride from the sample using one or more of an ion exchange cartridge and an exclusion apparatus; preconcentrating, using a solid phase extraction, at least one PFAS substance in the sample; digesting, using a working electrode and a counter electrode, the at least one PFAS substance to an amount of total organic fluoride; and determining, using an analyzer, the amount of total organic fluoride in the sample. Other aspects are described and claimed.

Abstract: We describe apparatuses, systems, method, reagents, and kits for conducting assays as well as process for their preparation. They are particularly well suited for conducting automated sampling, sample preparation, and analysis in a multi-well plate assay format. For example, they may be used for automated analysis of particulates in air and/or liquid samples derived therefrom in environmental monitoring.

Abstract: The present invention, belonging to the technical field of biological imaging, discloses a photo-activatable aggregation-induced emission probe with in-situ generation capability, a preparation method therefor and an application thereof. The preparation method is as follows: A bis(2-(2-hydroxybenzylidene)amino)aryl disulfide compound is reacted with thiol to obtain a photo-activatable aggregation-induced emission probe, which has a structure as shown in formula III. In the present invention, the photo-activatable aggregation-induced emission probe is aggregated into a specific organelle, and a 2-(2-hydroxyphenyl)benzothiazole compound having the aggregation-induced emission property is generated through a photo-oxidation reaction.

Abstract: The present invention describes a test kit for the detection of fat-soluble vitamins in serum using a method based on high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The internal standard (IS) solution included in the kit is based on methanol, acetonitrile and isopropyl alcohol solvents. Ammonium acetate is added to the IS solution to make it more stable and last for longer storage time. The application of this kit can significantly improve the recovery and detection sensitivity of vitamins A, E, K1 and K2 in serum without additional sample enrichment, make sample preparation process simpler and more efficient, keep processed samples stable for longer time, and lower the overall cost for more accurate and repeatable test results.

Abstract: Compositions and methods for determining the origin location of subterranean rock samples. In some implementations, the compositions include a nanoparticle tag that includes a natural polysaccharide, a fluorescent dye, and superparamagnetic nanoparticles. In some implementations, a method of determining the origin location of a subterranean rock sample includes mixing the nanoparticle tag into a fluid, flowing the fluid into a subterranean formation, recovering subterranean rock samples from the formation, separating tagged rock samples from untagged rock samples using a magnet, and determining the origin location by analyzing a fluorescent signal of the nanoparticle tag.

Abstract: A dry test piece for albumin measurement is based on the improved BCP method as a principle, and enables the measurement of albumin at a high sensitivity. The test piece includes a support; and a reagent holding layer provided on the support and on which a sample is spotted. The reagent holding layer contains a protein denaturation agent (component A), an SH reagent (component B), bromcresol purple (component C), and a nonionic surfactant (component D). In the reagent holding layer, a weight ratio (D/C) of the component D to the component C is 0.3 to 13, a content of the component C relative to an amount of the spotted sample is 0.4 ?g/?L to 5.4 ?g/?L, a content of the component D relative to the amount of the spotted sample is 25 ?g/?L or less.

Abstract: The present invention discloses mass spectrometry (MS)-based methods and tagging reagents for qualitative and quantitative analysis of post-translational modified (PTM) proteins in biological and clinical samples. The present invention utilizes thiol-containing tagging reagents which are able to bind to or derivatize biomolecules, preferably post-translational modified (PTM) polypeptides such as citrullinated and homocitrullinated polypeptides. The tagging reagents are preferably biotin-derived tags able to react with a side chain of the modified polypeptides.

Abstract: Novel organoselenium selective ligands are presented and designed to determine metal ions in a sample. These ligands are used as complexing agents in a dispersive liquid-liquid microextraction procedure of copper and zinc ions. The procedure has a shortened extraction time, minimal organic solvent types, and lower amounts of solvents, as well as easy operation and high enrichment efficiency.

Abstract: A system, apparatus configured to dynamically vary an extraction distance between an extraction volume and a sample surface through a probe assembly height adjustment apparatus operably coupled to a motor in which a processor can move the probe assembly height adjustment apparatus to maintain the extraction distance, or tune the extraction distance to optimize sampling performance. Methods for calibrating, tuning an extraction distance between an extraction volume and a sample surface.

Abstract: A device that includes a polymeric layer, wherein the polymeric layer comprises (A) a polymer and, incorporated within the polymeric layer, (B) a compound, or a protonate or salt thereof, wherein the compound, or a protonate or salt thereof, has a structure that includes at least one moiety configured for reversible, non-covalent binding of the anionic sulfide species.

Abstract: A device and method for analyte detection and analytes in a particulate bearing fluid such as whole blood having an instrument for partitioning the particles from the fluid that is integrated with a detector for analyses of one or more particulate bearing fluid analytes while the particles in the particulate bearing fluid are partitioned.

Abstract: Provided are methods for preparing a biological sample for analysis for the presence of a virus, or an exosome or other extra-cellular vesicle, by matrix assisted laser desorption ionisation time of flight mass spectrometry (MALDI-ToF MS). The preparation involves mixing the sample with at least one cationic viral envelope/vesicle disruptor compound, or at least one disulphide reducing agent, or a combination thereof; and at least one mass spectrometry grade solvent. Also provided are methods for analysing a biological sample for the presence of a virus, or an exosome or other extra-cellular vesicle, using MALDI-ToF MS once prepared.

Abstract: 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.