An analytical method for detecting presence of oxidizing substances by measuring degradation of peptides may include preparing a test preparation that includes a peptide and a sample. The peptide degrades in the presence of oxidizing substances. The method may include detecting impurities of the peptide in the test preparation in which detected impurities indicate presence of oxidizing substances in the sample. Examples include using high performance liquid chromatography to detect, identify, and quantify impurities of the peptide indicating presence of oxidizing substances in the sample. Exemplary oxidizing substances include peroxide-containing, chlorine-containing compounds, and bromine-containing compounds. Exemplary peptides include vasopressin.

The present invention provides reagents for instrumentation quality control and methods of use thereof. In particular, sets of peptides or other molecules are provided for evaluating the performance of instruments with mass spectrometry (MS) and/or liquid chromatography (LC) functionalities.

The measurement of glutaraldehyde-based biocides in seawater without the use of a derivatization agent. The measurement of glutaraldehyde-based biocides in seawater may be performed without additional components to reduce background interferences. The concentration of a glutaraldehyde-based biocides in a seawater sample is determined using reversed phase liquid chromatography and a gradient mobile phase of acetonitrile and deionized water. Systems for determining the concentration of glutaraldehyde-based biocide in a seawater injection system are also provided.

Disclosed herein are chromatography instrument support systems, as well as related apparatuses, methods, computing devices, and computer-readable media. For example, in some embodiments, a chromatography instrument support apparatus may include: first logic to generate one or more peak locations for a chromatogram data set and to generate one or more baselines for the chromatogram data set, wherein an individual peak has an associated baseline, and wherein the first logic includes a machine-learning computational model that outputs estimated peak locations and estimated baselines; second logic to cause the display of the one or more peak locations and the one or more baselines concurrently with the display of the chromatogram data set; and third logic to, for individual peaks, generate an associated integrated value representing an area above the associated baseline and under a portion of the chromatogram data set corresponding to the individual peak.

The present invention generally pertains to methods of characterizing charge variants of a protein of interest. In particular, the present invention pertains to the use of desalting size exclusion chromatography-reduced peptide mapping mass spectrometry to identify charge variants separated by capillary isoelectric focusing.

An information processing device processes information based on a plurality of chromatograms obtained by analyzing a plurality of samples. A determination processing unit determines presence or absence of each of a plurality of target components in each sample based on the plurality of chromatograms. A list generation processing unit generates a list associating the plurality of target components with each sample and indicating the presence or absence of each of the plurality of target components in each sample determined by the determination processing unit. Checking the list enables prompt confirmation of the presence or absence of the target components in each of the plurality of samples.

An information processing device processes information based on a plurality of chromatograms obtained by analyzing a plurality of samples. A determination processing unit determines presence or absence of each of a plurality of target components in each sample based on the plurality of chromatograms. A list generation processing unit generates a list associating the plurality of target components with each sample and indicating the presence or absence of each of the plurality of target components in each sample determined by the determination processing unit. Checking the list enables prompt confirmation of the presence or absence of the target components in each of the plurality of samples.

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 non-pyrrolidinone nitrogen-containing compound. The methods and systems can identify the presence or absence of the gas chromatography marker and/or the non-pyrrolidinone nitrogen-containing compound. The compositions, methods, and systems can optionally utilize a spectroscopic marker.

Provided is, for example, a method for analyzing steroid hormones contained in a body hair sample from an animal, wherein body hair collected from an animal is used as the body hair sample, and the method includes: an extraction step of extracting a plurality of types of steroid hormones from the body hair sample by using a 45 vol % to 55 vol % aqueous acetonitrile solution containing 0.1 M trifluoroacetic acid; and a measurement step of measuring the amounts of the plurality of types of steroid hormones extracted.

Methods and system for identification of dimer species using online chromatography and electrospray ionization mass spectrometry are provided. Also provided are methods and system for quantitation of heterodimer species using immunoprecipitation and liquid chromatography-mass spectrometry.