Systems and methods are provided for analyzing isotopes of a gas from a wellbore to determine geological information associated with the wellbore. A drill device can be used to drill rocks or particles in a wellbore, which can cause a gas to be released within the wellbore. Fluid can be pumped into the wellbore as the drill bit drills the rocks or particles and the fluid, along with the gas released, can flow through the wellbore and to a surface of the wellbore. A gas detector can be positioned near the wellbore for detecting an amount of gas and a type of gas in the fluid and gas mixture and transmitting data about the amount and type of the gas to a computing device. The computing device can output data based on the amount and type of gas in the mixture for determining geological information about the wellbore.

The present invention is a method for detecting a specific disease based on the result of a measurement in which the amount of a peptide serving as a biomarker contained in a biological sample is determined by using an LC-MS. A pretreatment process performed before the measurement using the LC-MS includes the steps of preparing a mixed sample solution by adding a stable isotope reagent and a trifluoroacetic acid to the biological sample, where the stable isotope reagent is prepared beforehand by labeling the peptide with a stable isotope; boiling the mixed sample solution; injecting the mixed sample solution after boiled into a solid-phase extraction column to make the peptide be retained in the solid-phase extraction column; and passing a water-soluble organic solvent through the solid-phase extraction column to elute the peptide retained in the solid-phase extraction column and collect the eluate.

The present disclosure is directed at an antibody conjugate having an antibody and a tag, wherein one or more element(s) present in the antibody exhibit an isotope ratio which differs from the naturally occurring isotope ratio of the one or more element(s), wherein the amount of the isotope which is less-common in nature, is increased to at least 4% of the atoms of the respective element in the antibody, as well as uses thereof.

The present specification relates to a method for analyzing a deuterated compound by chromatography, and manufacturing an organic light emitting device using a deuterated compound selected based on the analyzed data.

The present disclosure provides for collection and separation systems, collection and separation methods, isotope analsis systems, methods of processing samples to analyze .sup.15N, .sup.13C, and S.sup.34, and the like. In an aspect, the present disclosure provides for a system that includes a collection system in gaseous communication with a first device, wherein the collection system is configured to isolate two or more gases of a gaseous sample and configured to introduce each to a second device independently of one another.

The present disclosure provides methods of identifying or certifying an animal that consumed a traceable diet comprising a C.sub.1 metabolizing microorganism.

Methods of quantifying a N.sup.2-(1-carboxyethyl)-2′-deoxyguanosine (CEdG) levels in biological samples and comparing those levels to known normal levels can diagnose a number of metabolic disorders or complications associated therewith, including diabetes, its associated complications, and cancer. Methods can also determine whether therapies for disorders are effective by measuring CEdG levels before and after treatment. Measurement of CEdG levels is achieved by using liquid chromatography electrospray ionization tandem mass spectrometry.

The present invention relates to a method for determining the origin of glutamic acid in a sample and, in a broader sense, relates to a method for determining the origin of an amino acid. The present invention makes it possible to measure the stable isotope ratio, with a considerably higher accuracy than that of conventional methods, by measuring the δ13C of glutamic acid (amino acid) by elemental analysis-stable isotope ratio mass spectrometry (EA-IRMS) and measuring the δ15N by gas chromatography-stable isotope ratio mass spectrometry (GC-IRMS). In addition, the present invention makes it possible to determine the origin of glutamic acid (amino acid) by comparing the stable isotope ratio of the glutamic acid (amino acid) whose origin is unclear with the stable isotope ratio of glutamic acid (amino acid) whose origin is clear.

The present specification relates to a method for analyzing deuterated benzene by gas chromatography, and preparing a deuterated compound using deuterated benzene selected based on the analyzed data.

A system for controlling flow of gas in a continuous flow isotope ratio analyser is provided. The system comprises gas inlet and gas outlet lines for providing gas into and from a measuring cell, and at least one switchable flow restriction on the gas inlet line, for selectively controlling gas flow into the isotope ratio analyser. Also provided is a method for determining an isotope ratio using the system according to the invention.