PROCEDURE FOR SPECTROMETRICALLY MEASURING THE CONCENTRATION RELATIONSHIP OF TWO ISOTOPES IN A GAS.

摘要

A method of measuring spectrometrically in an isotopic gas, comprising the steps of introducing a gaseous test sample containing 12CO2 and 13CO2 as component gases into a cell, measuring the absorbances of light transmitted through the gaseous test sample at suitable wavelengths for the respective component gases, and determine the concentrations of the respective component gases based on the calibration curves prepared by the mediation of the gaseous samples respectively containing the component gases in known concentrations, the procedure characterized in that two samples of gas test obtained from a living body are measured and, if the concentration of 12CO2 in one of the two gas test samples is higher than a concentration of 12CO2 in the other example of gas test, said gas test sample is diluted at a concentration level 12CO2 equivalent to the other sample a gas test, then the absorbances of transmitted light through said two gas test samples are measured and then the concentration ratios of 13CO2 / 12CO2 in the respective gas test samples are calculated.