The present disclosure provides compositions, methods, and systems for identifying marked hydrocarbon fluids. These compositions, methods, and systems utilize a gas chromatography marker including a pyrrolidinone. The methods and systems can identify the presence or absence of the gas chromatography marker and/or the pyrrolidinone. The compositions, methods, and systems can optionally utilize a spectroscopic marker.

The present disclosure provides compositions, methods, and systems for identifying marked hydrocarbon fluids. These compositions, methods, and systems utilize a gas chromatography marker including a pyrrolidinone. The methods and systems can identify the presence or absence of the gas chromatography marker and/or the pyrrolidinone. The compositions, methods, and systems can optionally utilize a spectroscopic marker.

The present disclosure provides compositions, methods, and systems for identifying marked hydrocarbon fluids. These compositions, methods, and systems utilize a gas chromatography marker including a pyrrolidinone. The methods and systems can identify the presence or absence of the gas chromatography marker and/or the pyrrolidinone. The compositions, methods, and systems can optionally utilize a spectroscopic marker.

Provided are methods for detecting or determining the amount of guanidinoacetate (GAA), creatine, and creatinine by mass spectrometry.

Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

A method for qualitative and quantitative multiplexing of drug analytes from dried blood samples includes the steps of mixing an Internal Standard solution with a first diluent in a vessel, adding the dried blood sample to the vessel, sonicating the vessel containing the Internal Standard solution, the first diluent and the dried blood sample, removing the dried blood sample from the vessel so that a final sample can be attained, and analyzing at least a portion of the final sample using one of LC-MS and LC-MS/MS to simultaneously determine the presence or absence of a plurality of different analytes in the dried blood sample. The Internal Standard solution can include at least 8, 15, 25 or 50 Internal Standards. The dried blood sample is generated using less than 50 L, 20 L or 10 L of blood. The step of analyzing includes simultaneously determining the presence or absence of at least 15, 60, 90 or 130 different analytes. A ratio of the number of analytes for which the presence or absence is being determined to the number of Internal Standards in the Internal Standard solution is at least approximately 2:1. A ratio of the number of analytes for which the presence or absence is being determined to the volume (in L) of the final sample being analyzed is at least approximately 2:1. A ratio of the number of analytes for which the presence or absence is being determined to the volume (in L) of blood from which the dried blood sample was obtained is at least approximately 4:5.

The present invention relates to a plastic reference material and a method of manufacturing the same, wherein the concentration of at least one chemical substance is characterized from a signal intensity of the chemical substance and a signal intensity of the isotope-labeled chemical substance of the chemical substance obtained using the pyrolysis GC-MS instrument by weighing a mass of a candidate material for the plastic reference material using a balance, weighing an isotope-labeled chemical substance of the chemical substance using a balance, preparing a mixed solution by dissolving the weighed candidate material for the plastic reference material and the weighed isotope-labeled chemical substance in a solvent, introducing a product resulting from evaporation of the solvent from the mixed solution into a pyrolysis GC-MS instrument, and calculating the concentration of the chemical substance included in the candidate material for the plastic reference material.

Disclosed are methods, libraries, and samples for quantifying a target analyte in a laboratory sample including the target analyte. The methods typically include the step of estimating the amount of the target analyte in the laboratory sample from mass spectrometric data including signal intensities for the target analyte and one or more internal standards, where the mass spectrometric data are an output of a mass spectrometric analysis of a target sample produced from the laboratory sample and a predetermined amount of the one or more internal standards. The present disclosure also provides a method for analyte quantification. The method comprises adding one or more calibrators to a sample comprising one or more analytes; applying mass spectrometry (MS) to the sample; and using a trained machine learning model to determine an absolute concentration of the one or more analytes.

The present invention provides a method for measuring moisture content in a separator of secondary battery by using a gas chromatograph equipped with a headspace sampler. The separator of secondary battery may be a safety reinforced separator (SRS) in which inorganic substance particles and a binder polymer are coated on a polyolefin substrate.

A separation device receives a known or unknown glycan that is co-injected with three different oligomers maltooligosaccharide (MOL). A detector measures the separated glycan and the separated three different oligomers as intensity peaks that are a function of migration time. The migration times of a plurality of other oligomers of MOL are calculated from the migration times of the three different oligomers. Glucose unit (GU) values for the intensity peaks of the separated glycan are calculated by comparing their migration times to the calculated migration times of the plurality of other oligomers of MOL. The processor identifies the structure of the glycan by comparing the calculated GU values of the intensity peaks of the separated glycan to a database of GU values for known glycan structures.