JPH04309861A - Extremely small quantity isotope analyzing device - Google Patents

Abstract

PURPOSE:To detect the isotope with high precision and sensitivity by oxidizing a compound taken from an analyzing column, decomposing the compound to carbon dioxide and water, and detecting the radioactive isotope from a sample which is separation-discharged into carbon dioxide and water. CONSTITUTION:The hydrocarbon separated from a sample transported by a sample introducing mechanism 2 by a separating column 3 is detected by a hydrocarbon detector 4, and supplied into a trap 7 through a selector valve 5. Further, the constituents other than the hydrocarbon is discharged outside an analyzing system from an atmosphere opened port 6. At the trap 7, the sample is cooled and concentrated, and then heated and evaporated, and introduced into an analyzing column 8, and the hydrocarbon is separated with high resolving power. In an organic substance decomposing furnace 9, the hydrocarbon discharged from the column 8 is changed into CO2, and H2O2 and in a separating cylinder 10, a time difference is generated between the discharge time points of CO2 and H2O2 and the gas is discharged into a selector valve 11. From the valve 11, the CO2 discharged from the furnace 9 is discharged into a radioactive isotope detector 13, and the isotope of the carbon contained in the CO2 is measured.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for analyzing hydrogen and carbon isotopes contained in trace amounts of compounds.

0002

BACKGROUND OF THE INVENTION In research on the growth of plants, metabolism is measured using radioactive isotopes of carbon and hydrogen. In such research, it is necessary to measure hydrogen and carbon isotopes contained in minute amounts of compounds emitted into the atmosphere from plants, so the target hydrocarbons are concentrated before measurement. There is.

0003

[Problems to be Solved by the Invention] In this concentration, the air sample is cooled with a refrigerant such as liquid nitrogen to fractionate the compounds.
There is a problem that even carbon dioxide is concentrated, resulting in low measurement accuracy. The present invention was made in view of these problems, and its purpose is to detect trace amounts of carbon and hydrogen isotopes that exist in the form of compounds in the air with high accuracy and sensitivity. The objective is to provide a new analytical device that can

0004

[Means for Solving the Problems] In order to solve such problems, the present invention provides a preparative means connected downstream of the sample introduction mechanism for selectively discharging compounds, and a preparative means connected downstream of the sample introduction mechanism. a concentration means connected to the side and equipped with a heating means for liquefying and concentrating the compound and vaporizing it; an analytical column for separating hydrocarbons vaporized and discharged from the concentration means; and an analytical column for oxidizing the compound from the column. A furnace for decomposing carbon dioxide and water into carbon dioxide and water, a separation means for separating a sample discharged from the furnace into carbon dioxide and water, and a means for detecting radioactive isotopes from the sample discharged from the separation means. I did it like that.

[0005]

[Operation] The compounds in the air selected by the preparative means are concentrated by the concentrating means and then injected into the analytical column in a short time. This makes it possible to reliably eliminate components in the air mixed in during concentration. Next, the compound discharged from the analytical column is decomposed into carbon dioxide and water in a furnace, and each is separated and discharged by a detection means for measuring radioactive isotopes. This makes it possible to select and measure carbon and hydrogen isotopes contained in a compound.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below based on illustrated embodiments. FIG. 1 shows an embodiment of the present invention, in which reference numeral 2 denotes a sample introduction mechanism, a carrier gas source (not shown) is connected to a carrier gas inlet 1, and a sample introduction mechanism is connected to the other end of the sample introduction mechanism. column 3 is connected. The preparative column 3 separates only compounds, such as hydrocarbons, from the sample injected into the sample introduction mechanism 2 and carried by the carrier gas, and discharges it downstream. 4 is a compound detector, for example a hydrocarbon detector, which detects the point in time when hydrocarbons are discharged from the gas components discharged from the preparative column 3; The switching valve 5 is switched to the trap 7 side (described later), and when discharge of components other than hydrocarbons is detected, the switching valve 5 is switched to the atmosphere opening port 6 side to remove the discharged components from the analysis system. Discharge.

The trap 7 contains liquid nitrogen as a refrigerant and is equipped with heating means to rapidly vaporize the target component, and the incoming sample is cooled to a temperature similar to that of liquid nitrogen and concentrated. When the sample is finished, the heating means is activated to vaporize the sample at once and inject it into the analytical column 8. As a result, the sample is injected into the analytical column 8 in an extremely short time, and hydrocarbons are separated with high resolution.

Reference numeral 9 denotes an organic matter decomposition furnace containing an oxidation catalyst, which converts the hydrocarbons discharged from the analytical column 8 into carbon dioxide (CO2) and water (H2O), and discharges the converted gas into a separation column 9. This separation cylinder 10 accommodates a carbon dioxide adsorbent or a water absorbing agent, and discharges the carbon dioxide and water, which have flowed in at the same time, to the switching valve 11 with a time difference between the discharge points. When carbon dioxide is discharged from the organic substance decomposition furnace 9, the switching valve 11 is switched to the radiation isotope detector 13 side, and the carbon dioxide is discharged to the radiation isotope detector 13 such as a scintillation counter or a mass spectrometer. This makes it possible to measure carbon isotopes contained in hydrocarbons.

[0009] Reference numeral 10 is a reduction furnace configured to contain copper particles or copper powder, and when the water is discharged from the separation tube 10, the water introduced by operating the switching valve 11 reacts with the copper. copper oxide is produced, and hydrogen produced at this time is discharged to the radiation isotope detector 13. This makes it possible to measure hydrogen isotopes contained in hydrocarbons while preventing moisture from entering the radiation isotope detector 13. After concentrating the hydrocarbons diluted with air, etc., the hydrocarbons are selectively extracted using an analytical column and decomposed into carbon dioxide and water. Carbon monoxide, nitrogen, oxygen, etc. can be reliably eliminated. Note that in this example, water is reduced to hydrogen and then discharged to the isotope detector, but it is possible that the measurement accuracy will not be affected even if the water is discharged to the measurement means in the form of water. it is obvious.

[0010] Also, in this example, the case where isotopes of carbon and hydrogen contained in the form of hydrocarbons was explained as an example, but it can also be applied to other compounds containing carbon and hydrogen. It is clear that similar effects can be achieved.

[0011]

[Effects of the Invention] As explained above, in the present invention,
A preparative means connected to the downstream side of the sample introduction mechanism to selectively discharge the compounds; and a concentrating means connected to the downstream side of the preparative means to liquefy and concentrate the compounds as well as a heating means for vaporizing them. , an analytical column that separates the compounds vaporized and discharged from the concentration means, a furnace that oxidizes the compounds from the analytical column and decomposes them into carbon dioxide and water, and a sample discharged from this furnace that separates them into carbon dioxide and water. Since it is equipped with a separation means that separates the sample into two, and a means for detecting radioactive isotopes from the sample discharged from the separation means, the compound is removed after removing harmful components such as carbon dioxide from the air using the preparative separation means. The compound can be concentrated with a concentration means and then injected into an analytical column in a short time, allowing the compound to be fractionated with extremely high precision. Furthermore, it is possible to separate and measure the carbon and hydrogen isotopes contained in the compound by decomposing the compound into carbon dioxide and water, separating each, and discharging them using a detection means that measures radioactive isotopes.

[Brief explanation of drawings]

FIG. 1 is a structural diagram showing an embodiment of the present invention.

[Explanation of symbols]

2 Sample introduction mechanism 3 Preparative column 4 Compound detector 5 Switching valve 7 Trap 8 Column for analysis 9 Decomposition furnace 10 Separation tube 11　Switching valve 12 Reduction furnace 13 Radiation isotope detector

Claims (1)

[Claims] Claim 1: A preparative means connected to the downstream side of the sample introduction mechanism to selectively discharge the compound; and a heating means connected to the downstream side of the preparative means to liquefy and concentrate the compound as well as vaporize it. an analytical column for separating the compounds vaporized and discharged from the concentration means; a furnace for oxidizing the compounds from the column and decomposing them into carbon dioxide and water; A trace isotope analyzer comprising a separation means for separating carbon dioxide and water, and a means for detecting radioactive isotopes from a sample discharged from the separation means.