Abstract: An angiosperm index-1 and an angiosperm index-2 are correlated to an age of a liquid hydrocarbon sample and can be used to distinguish oil age of Late Cretaceous (100-65 million years before present, or 100-65 Ma BP) vs. Paleogene (65-55 Ma BP) vs. Eocene or younger (<55 Ma BP). This method improves over existing methods that cannot distinguish oil age between Late Cretaceous and Miocene (ca. 100-5 Ma BP).

Abstract: Analyte collection and testing systems and methods, and more particularly to disposable oral fluid collection and testing systems and methods. Described herein are methods and apparatuses to achieve significant improvements in the detection of fluorescence signals in the reader.

Abstract: Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.

Abstract: A method of determining saturate, aromatic, resin, and asphaltene (SARA) fractions of a hydrocarbon fluid sample, including: i) microfluidic mixing that forms a mixture including the hydrocarbon fluid sample and a solvent fluid that dissolves asphaltenes; ii) performing optical spectroscopy on the hydrocarbon fluid sample-solvent fluid mixture resulting from i); iii) microfluidic mixing that forms a mixture including the hydrocarbon fluid sample and a titrant fluid that precipitates asphaltenes; iv) microfluidically precipitating asphaltenes from the hydrocarbon fluid sample-titrant fluid mixture resulting from iii); v) performing a microfluidic filtering operation that removes precipitated asphaltenes from the mixture resulting from iv) while outputting permeate; vi) performing optical spectroscopy on the permeate resulting from v); vii) determining an asphaltene fraction percentage of the hydrocarbon fluid sample based on the optical spectroscopy performed in ii) and vi); viii) sequentially separating sa

Abstract: A first method for determining an amount of water in a sample includes the step of providing a reagent including: sulfur dioxide or a derivative thereof; a base; an optional hydrogen halide or hydrogen halide donor; a solvent; and a sulfonic acid; and the step of titrating the sample with the reagent. A second method for determining an amount of water in a sample includes the step of providing the aforementioned reagent, combining the sample with the reagent; and adding a source of iodine to the sample and/or the reagent. The reagent may alternatively consist essentially of sulfur dioxide or a derivative thereof; imidazole and/or a derivative thereof; an optional hydrogen halide or hydrogen halide donor; acetonitrile; methane sulfonic acid; and methanol and/or ethanol.

Abstract: A sampling device is provided for concentrating a liquid specimen sample, including a filtration assembly, which includes a tubular container and a plunger. The plunger includes a plunger head and a plunger rod that is shaped so as to define an internal plunger space having a plunger-space proximal opening through a proximal end of the plunger rod. The sampling device is configured such that a filter is removable from the tubular container via the plunger-space proximal opening while the plunger head is within the tubular container. Other embodiments are also described.

Abstract: The invention generally relates to systems and methods for quantifying an analyte extracted from a sample. In certain embodiments, the invention provides methods that involve introducing a solvent into a capillary, introducing the capillary into a vessel including a sample such that a portion of the sample is introduced into the capillary, moving the sample and the solvent within the capillary to induce circulation within the sample and the solvent, thereby causing the analyte to be extracted from the sample and into the solvent, analyzing the analyte that has been extracted from the sample, and quantifying the analyte. In certain embodiments, the quantifying step is performed without knowledge of a volume of the sample and/or solvent.

Abstract: The methods and systems may include LC-MS/MS. For example the method may include obtaining MS/MS data for a predetermined MS/MS transition for THC and/or at least one THC metabolite and CBD and/or at least one CBD metabolite, and determining a ratio of the amount of the CBD and/or at least one CBD metabolite to the amount of the THC and/or at least one THC metabolite for the biological sample. In certain embodiments, the methods and/or systems are used to distinguish CBD from THC use in a subject.

Abstract: Microfluidic methods of altering the spacing of a stream of objects. In an exemplary method, objects of the object stream may be transported in carrier fluid along a microfluidic channel structure having an inflow region, an outflow region, and an expanded region extending from the inflow region to the outflow region. The expanded region may have a greater cross-sectional area for fluid flow than each of the inflow region and the outflow region. Objects of the object stream may be moved from the inflow region to the expanded region such that at least a subset of such objects are moved closer to one another. Objects of the object stream may be passed from the expanded region to the outflow region to increase a distance between such objects.

Abstract: A system and method are provided for harvesting target biological substances. The system includes a substrate and a first and second channel formed in the substrate. The channels longitudinally extending substantially parallel to each other. A series of gaps extend from the first channel to the second channel to create a fluid communication path passing between a series of columns with the columns being longitudinally separated by a predetermined separation distance. The system also includes a first source configured to selectively introduce into the first channel a first biological composition at a first channel flow rate and a second source configured to selectively introduce into the second channel a second biological composition at a second channel flow rate. The sources are configured to create a differential between the first and second channel flow rates to generate physiological shear rates along the second channel that are bounded within a predetermined range.

Abstract: Disclosed is an integrated device for faeces sampling and occult blood detection, which has functions of quantitative collection, dissolution, filtration, detection with immune test strips of the faecal sample, and is convenient to carry and operate, and the device does not leak any liquid during storage, transportation and detection. The device can accurately collect a constant sample with no pollution and leakage, and can quickly determine results of occult blood without the aid of other items. The device can detect faecal occult blood at any time and at any place, can help to overcome the problem of low rate of inspection due to the inconvenience of faeces submission and inspection, further promote the detection of faecal occult blood, and can improve the early diagnosis and screening rate of colorectal cancer of the population.

Abstract: Provided are methods for determining the amount of tamoxifen and its metabolites in a sample by mass spectrometry. In some aspects, the methods provided herein determine the amount of N-Desmethyl Tamoxifen. In some aspects, the methods provided herein determine the amount of N-Desmethyl Tamoxifen and other tamoxifen metabolites. In some aspects, the methods provided herein determine the amount of tamoxifen, N-Desmethyl Tamoxifen, and other tamoxifen metabolites.

Abstract: Environmentally-friendly, aqueous concentrated reagent compositions are provided for dilution and use in suitable hematology analyzers for analyzing blood cells including for enumeration and sizing of blood cells, determination of hemoglobin parameters and differentiation of leukocyte subpopulations in a single blood cell sample.

Abstract: The present subject matter provides processes and kits for identifying the presence of waste water or human-derived pathogens, particularly those associated with the presence of human fecal matter, in surface or subsurface water sources.

Abstract: Methods, systems and techniques for the accurate measurement of breath-borne biomarkers are disclosed. Such methods, systems and techniques may be used for the purposes of detection and/or measurement in breath samples of biomarkers, e.g., biomarkers relating to a disease or a physiological condition.

Abstract: A process, or method, for testing ethanol-based fuel for phase separation and free-standing water, and then correcting the phase separation within the ethanol-based fuel. A method of introducing a desired amount of a chemical into suspension based on an amount of free-standing water that is within the ethanol-based fuel in order to treat and remove any and all amount of free-standing water that is remaining within the suspension.

Abstract: The present disclosure relates to a colorimetric humidity sensor and a method of preparing the same, and in the colorimetric humidity sensor that is an ultrafast colorimetric humidity sensor including a colorimetric member including humidity-responsive particles configured in a disordered monolayer arrangement on a substrate, the humidity-responsive particles are amorphous, porous, and polydispersed microspheres, and the colorimetric humidity sensor indicates a color change according to humidity upon light irradiation.

Abstract: The present disclosure provides a color chart and a test kit for estimating chemical oxygen demand of water. The color chart includes a blue component, an indigo component, an umber component, and an orange component. The test kit includes an oxidant, a reductant, an indicator, and the color chart. The present disclosure also provides a method for estimating chemical oxygen demand of water. The method includes providing a water sample; adding an oxidant to the water sample; heating the water sample; adding a reductant to the water sample; adding an indicator to the water sample, such that the water sample develops a color; and matching the color of the water sample with the color components of the color chart to estimate the chemical oxygen demand of the water sample.

Abstract: Methods, devices, and reagents are described for performing ratiometric assays for hemoglobin A1c. The methods involve a direct ratio determination between Hb A1c and normalized total hemoglobin utilizing a saturating amount of hemoglobin so that Hb A1c binds proportionately to a substrate. In some applications, the assay utilizes a proximity label system for signal generation and/or labeled magnetic beads. The methods can be configured as homogeneous or heterogeneous assays.

Abstract: Color quantification of chemical test pads and titration of analytes can be performed under different lighting conditions. In one embodiment, the lighting condition is estimated under which a digital image is captured and utilized to select a set of reference colors from which the quantified color is compared to determine the titration. In another embodiment, a plurality of comparisons are made with different lighting conditions with the result having the highest confidence level being selected to determine the titration.