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.

A method for analyzing light n-alkane components and carbon isotopes in deep and ultra-deep source rocks includes: (S1) subjecting a 5A molecular sieve column to aging; (S2) pyrolyzing a source rock; and allowing a pyrolysis product to enter the 5A molecular sieve column; where n-alkanes are adsorbed and retained by the 5A molecular sieve column; allowing an outflow to pass through a fractionation plate and an empty column or a weak polarity column to be discharged; and (S3) performing programmed heating such that the n-alkanes adsorbed on the 5A molecular sieve column are successively desorbed according to molecular weight, and then pass through the fractionation plate and the HP-5 or DB-5 column to enter a mass spectrometer for composition analysis or isotopic analysis. An analysis system is further provided.

The present invention includes a first flow path through which a sample gas flows, a first analyzer that is provided in the first flow path to measure total hydrocarbon concentration in the sample gas, a second flow path through which the sample gas flows, a non-methane non-ethane cutter that is provided in the second flow path to remove the hydrocarbon components other than the methane and the ethane in the sample gas, a second analyzer that is provided downstream of the non-methane non-ethane cutter in the second flow path to measure the total methane ethane concentration of the methane and the ethane in the sample gas, and a calculation part that calculates the concentration of the hydrocarbon components other than the methane and the ethane in the sample gas with use of the total hydrocarbon concentration by the first analyzer and the total methane ethane concentration by the second analyzer.

The invention relates to a method and the device which is required for its performing for the determination of the isotope ratio of carbon and/or nitrogen in an aqueous mobile phase which contains a sample. The method comprises the following steps: introduction of the aqueous mobile phase into a reactor (i), heating of the aqueous mobile phase with addition of oxygen in the reactor to a temperature of higher than 600° C. for the formation of a water containing sample gas (ii), reduction of the nitrogen oxides being present in the sample gas as well as removal of the contained oxygen (iii), removal of water from the sample gas by chemical drying and/or membrane gas drying (iv) and introduction of the dried sample gas into an isotope mass spectrometer (v). It is essential for the present invention that the introduction in step (i) is realized by introducing the aqueous mobile phase in a capillary tube which leads into the reactor with a gas mixture of oxygen and at least one inert gas, wherein the mass flow of oxygen and inert gas is regulated or controlled by at least one mass flow controller which is upstream with respect to the introduction and that after step (iv) removed water is actively pumped off.

A method for simultaneous determination of nitrogen and oxygen isotope compositions of natural nitrate and nitrite, which quantitatively converts natural nitrate and nitrite into an organic ester and a nitro-compounds respectively, and then nitrate and nitrite δ.sup.18O and δ.sup.15N are simultaneously determined by adopting a gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry coupling technology (GC/Py/GC/IRMS). According to the method for simultaneously determining the nitrogen and oxygen isotope compositions of the natural nitrate salt and nitrite salt, the small amount of sample does not result in the loss, acquisition, exchange and fractionation of nitrogen and oxygen.

The disclosure describes a method for simultaneous determination of nitrogen and oxygen isotope compositions of natural nitrate and nitrite, which quantitatively converts natural nitrate and nitrite into an organic ester and a nitro-compounds respectively, and then nitrate and nitrite δ.sup.18O and δ.sup.15N are simultaneously determined by adopting a gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry coupling technology (GC/Py/GC/IRMS). According to the method for simultaneously determining the nitrogen and oxygen isotope compositions of the natural nitrate salt and nitrite salt, the small amount of sample does not result in the loss, acquisition, exchange and fractionation of nitrogen and oxygen.

The invention is directed to a furnace suited for oxidation of a gaseous starting mixture comprising one or more sulphur compounds to obtain an oxidized gas mixture and reduction of the oxidized gas mixture to obtain a gaseous mixture of reduced sulphur compounds comprising an interior furnace space, an inlet conduit for the gaseous starting mixture, an inlet for supply of an oxygen comprising gas, a ceramic comprising outlet conduit provided with an inlet opening for the mixture of reduced sulphur compounds, an inlet for hydrogen and heating means, wherein the inlet opening of the outlet conduit is comprised of more than one opening which openings fluidly connect the interior furnace space and the interior of the outlet conduit.

A method for securing qualitative and quantitative information of a high molecular weight additive in a polymer resin sample is disclosed herein. In some embodiments, the method includes separating a fraction of a polymer resin sample using size exclusion chromatography (SEC), wherein the fraction corresponding to a high molecular weight additive, pyrolyzing the fraction in a pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) to obtain a mass spectrum of the pyrolyzed fraction; identifying a structure of the high molecular weight additive by comparing m/z values for fragment peaks in the mass spectrum to m/z values for fragment peaks in a mass spectrum of a standard, and determining the amount of the high molecular weight additive in the polymer resin sample, relative to the total weight of the polymer resin sample by comparing a sum of areas of the fragment peaks to a calibration line of the standard.

The present disclosure provides a method for analyzing an additive in a water-based polymer sample, comprising the steps of: (S1) putting the water-based polymer sample containing a polymer, the additive, and water as a solvent into a vial; (S2) putting a porous pouch containing a superabsorbent polymer (SAP) into the vial to absorb the water into the superabsorbent polymer; (S3) removing the porous pouch from the vial and collecting the concentrated polymer sample remaining in the vial; and (S4) performing a pyrolysis gas chromatography (Py-GC)/mass spectrometer (MS) analysis by introducing the concentrated polymer sample to the Py-GC/MS.

Tracing subterranean fluid flow includes providing a first polymeric tracer to a first injector, collecting a first aqueous sample from a first producer, and assessing the presence of the first polymeric tracer in the first aqueous sample. The first polymeric tracer includes a first polymer formed from at least a first monomer. The presence of the first polymeric tracer in the first aqueous sample is assessed by removing water from the first aqueous sample to yield a first dehydrated sample. pyrolyzing the first dehydrated sample to yield a first gaseous sample, and assessing the presence of a pyrolization product of the first polymer in the first gaseous sample. The presence of the pyrolization product of the first polymer in the first gaseous sample is indicative of the presence of a first subterranean flow pathway between the first injector location and the first producer location.