TH56576A - Methods for measuring stable isotopes for spectroscopic gas isotopic analysis and methods for estimating absorption capacity. - Google Patents

Abstract

The DC60 (22/11/44) gas isotopic analyzer, gas jet (21), was equipped for the compression of gas samples in cells (11a,11b). Compression of the gas samples produces results that are virtually identical to increasing the carbon dioxide concentration in the sample gas. This improves the S/N ratio for analysis and thus improves the ability to produce new data. The gas isotopic analyzer, gas jet (21), was equipped for the compression of gas samples in cells (11a,11b). Compression of the gas samples produces results that are virtually identical to increasing the carbon dioxide concentration in the sample gas. This improves the S/N ratio for analysis and thus improves the ability to produce new data.

Claims (5)

1. A method for measuring stable isotopes for spectrometric gas isotopic analysis is performed by introducing a gas sample containing a number of its constituent gases into a cell. The intensity of light transmitted through the cell at wavelengths appropriate for each constituent gas is measured, and the light intensity data is processed to determine the concentration ratio between the constituent gases. The constituent gases are 12CO2 and 13CO2. The method consists of four steps: First, introducing the gas sample into the cell and into a gas sprayer in contact with the cell. Second, spraying the gas sample in a predetermined volume into the cell using the sprayer, and then pressurizing the gas sample within the cell. Third, determining the absorbance of light transmitted through the cell at the appropriate wavelengths for each constituent gas. And fourth, determining the concentration ratio between the constituent gases in the gas sample based on a calibration curve prepared through measurements on the pressurized gas samples, each containing a known concentration of the constituent gases. 2. A method for measuring stable isotopes for spectrometric isotopic analysis of gases as specified in Reputation 1, where the gas sample is pressurized to 2 atm in a cell. 3. Method for Estimating the Absorption Capacity of Carbon Dioxide (CO2) for Use in Gas Isotope Analysis for Measuring the Concentration of 13CO2 in Gas Samples Containing 13CO2 and 12CO2 as Comparative Gases. The gas isotope analysis method consists of the following steps: introducing the gas sample into the cell and measuring the intensity of the light beam transmitted through the cell at a wavelength suitable for the analysis of the comparative gases, respectively; introducing air that has been passed through the container containing the carbon dioxide absorber as a comparison gas into the cell and measuring the intensity of the light beam transmitted through the cell at a wavelength suitable for the analysis of the comparative gases, respectively; and processing the data to indicate the measurement results, which are characterized by the following steps: performing the first light intensity measurement process by introducing air that has been passed through the container containing the carbon dioxide absorber into the cell; performing the second light intensity measurement process by introducing air that has not been passed through the container containing the carbon dioxide absorber into the cell; and estimating the absorption capacity of the carbon dioxide absorber based on the light intensity measured in the first and second light intensity measurement processes. 4. The method for estimating absorption capacity as specified in claim 3, whereby the procedure for estimating absorption capacity consists of a step of comparing the ratio of the light intensity measured in the first light intensity measurement step to the light intensity measured in the second light intensity measurement step with an initial value. 5. A method for estimating the absorption capacity as specified in claim 3, where the light intensity is measured at the appropriate wavelength for the analysis of carbon dioxide 12CO2 in the first and second light intensity measurement procedures.