CN104181245A - Method for analyzing hydrogen isotope in water of fluid inclusion - Google Patents

Abstract

The invention discloses a hydrogen isotope analysis method in fluid inclusion water. The method adopts a water sample collection instrument and a TC/EA-IRMS combined instrument; the water sample collection instrument includes a vacuum communication pipeline, a sample burst device and a water sample collection instrument. Collecting device; The water sample collecting device includes a quartz collecting tube, and the quartz collecting tube is formed with a capillary part at its lower end; the TC/EA-IRMS combined instrument includes a pyrolysis/elemental analyzer (TC/EA) and Isotope ratio mass spectrometer (IRMS), the pyrolysis/elemental analyzer includes a high temperature reaction tube and a gas chromatographic column; due to the adoption of a capillary part and a solid sampling method, the amount of sample required is less, which can effectively save fluid parcels body sample size.

Description

A Hydrogen Isotope Analysis Method in Fluid Inclusion Water

technical field

The invention relates to the technical field of stable isotope analysis, in particular to a hydrogen isotope analysis method in fluid inclusion water.

Background technique

Fluid inclusions refer to one or more fluid inclusions that are filled and sealed in tiny holes, fissures or intergranules of minerals by rock-forming ore-forming fluids (gas-liquid-containing fluids or silicate melts) during the growth of mineral crystallization. A phase state substance (liquid, gas or solid), which has been sealed in the main mineral since its formation and has a phase boundary with the main mineral. Since the determination of the isotope composition of fluid inclusions (sometimes referred to as inclusions or inclusions) can provide unique information for the study of diagenetic and mineralization theory, paleoclimate and paleotemperature reconstruction, gemstone mine exploration, gemstone identification, etc. It has been developed rapidly and widely used.

Hydrogen isotope analysis in traditional fluid inclusion water (fluid inclusions usually contain water, experiments show that the content range is generally 50% to 98% by weight) usually in vacuum or inert gas environment, by thermal burst method, crushing method Or the vacuum ball milling method releases the water in the fluid inclusions, and then collects and purifies it through the cooling system, and then transfers the water sample to the tube furnace by gasification to use active metals (such as uranium U, zinc Zn, chromium Cr or manganese Mn) at high temperature ) as a reducing agent to convert it into hydrogen, which is collected by a gas collection tube and then enters an isotope ratio mass spectrometer (IRMS, the full name is Isotope Ratio Mass Spectrometry) for detection.

The isotope ratio analysis of fluid inclusion samples requires appropriate particle size and mineral content. Here, the mineral content refers to the weight of the sample showing inclusions with the same characteristics under the cold and hot stage microscope. The particle size refers to the size of each inclusion particle. The appropriate particle size Generally, it is 0.1-0.4 mm (fluid inclusions are generally sorted out from mineral particles by experience under a cold and hot stage microscope. These particles are large and small. The small particle size is only a few tenths of a micron, and the large particle size is several millimeters) . If the particle size is too small, the inclusions will lose too much; if the particle size is too large, the inclusions will be difficult to burst (if the particle size is too small, some large inclusions will be destroyed when the sample is ground, or only a few inclusions can be selected from the selected inclusions. A small part of the sample particles with a suitable particle size. The particle size is too large, which means that it takes a longer heating time to make the sample particles reach the burst temperature, and it is not easy to burst). For conventional hydrogen isotope analysis in inclusion water, in order to achieve satisfactory isotope ratio analysis results (such as the signal peak intensity of mass spectrometry samples), the amount of water required for testing is generally about 2-10uL when liquid samples are injected (that is, it is necessary to collect 2 ~10uL water sample), at this time, at least 3g of sample (for example, 3~10g) is required, which puts forward higher requirements for mineral separation. In the actual mineral separation, inclusion samples often cannot be selected from 3g samples, and the hydrogen produced in this way Less often, when entering IRMS mass spectrometry detection, the measured isotope ratio is often inaccurate due to the low signal of the sample.

Contents of the invention

The main purpose of the present invention is to provide a hydrogen isotope analysis method in fluid inclusion water which effectively reduces the sample amount required for hydrogen isotope analysis in fluid inclusion water.

In order to achieve the above object, the present invention proposes a hydrogen isotope analysis method in fluid inclusion water, which is characterized in that it comprises the following steps:

Step 1: Use a water sample collection instrument to collect water samples in the fluid inclusions; wherein the water sample collection instrument includes a vacuum communication pipeline, a sample burst device and a water sample collection device; the sample of the fluid inclusions is passed through the The gas sample generated after the bursting of the sample bursting device is introduced into the water sample collection device through the vacuum communication pipeline; the water sample collection device includes a quartz collection tube, and the quartz collection tube is formed with a capillary part at its lower end. The capillary part condenses the introduced gas sample inside to collect the water sample in the fluid inclusion;

Step 2: Use the TC/EA-IRMS combined instrument to analyze the collected water samples for hydrogen isotope in water; wherein the TC/EA-IRMS combined instrument includes pyrolysis/elemental analyzer (TC/EA) and isotope ratio Mass spectrometer (IRMS), the high-temperature cracking/elemental analyzer includes a high-temperature reaction tube and a gas chromatographic column, and the high-temperature reaction tube is used to melt the capillary part where the water sample is collected to release water vapor and make its cracking reaction generate For the mixed gas of hydrogen, the hydrogen is separated from the mixed gas by using a gas chromatographic column; the separated hydrogen is received by the isotope ratio mass spectrometer and subjected to hydrogen isotope analysis in water to obtain the hydrogen isotope ratio.

The vacuum communication pipeline in the step 1 includes a low vacuum pipeline communicated with a low vacuum pump, a high vacuum pipeline communicated with a high vacuum pump, and a water sample collection pipeline communicated with the water sample collection instrument. The sample collection pipeline is provided with at least two openings communicating with the sample bursting device or the water sample collection device, and the sample bursting device includes a sample tube for containing the sample of the fluid inclusion, and the A furnace for heating the sample tube and heating it.

The step 1 includes the following specific steps:

Step 1.1: Install the sample tube and the quartz collection tube on the corresponding opening of the water sample collection pipeline, and block the unused opening on the water sample collection pipeline with a piston vacuum plug;

Step 1.2: Turn on the low vacuum pump, open the low vacuum valve between the low vacuum pump and the water sample collection pipeline, open the sample burst valve on the sample tube and the water sample collection valve on the quartz collection tube, and draw low vacuum;

Step 1.3: Put the heating furnace on the sample tube and heat it to 150-200 degrees Celsius to degas and remove the superficially adsorbed water;

Step 1.4: When the vacuum degree reaches below 10Pa, turn on the high vacuum pump, close the low vacuum valve, open the high vacuum valve between the high vacuum pump and the water sample collection pipeline, and close the sample burst when the vacuum degree reaches below 0.1Pa Valves, water sample collection valves and high vacuum valves;

Step 1.5: Heat the heating furnace to about 400 degrees Celsius to burst, open the sample burst valve, cover the corresponding quartz collection tube with cold liquid, then open the water sample collection valve to start collecting water samples, and then close the water sample collection valve;

Step 1.6: Hold the lower end of the capillary with tweezers, then use a liquefied gas torch to quickly seal the capillary at 3-4 mm above the cold liquid, and remove the capillary where the water sample is collected after fusing.

The water sample collection pipeline is also provided with a cold trap, and a Dewar bottle equipped with liquid nitrogen is placed on the cold trap. The openings on the water sample collection pipeline are symmetrically distributed on both sides of the cold trap. The two ends of the trap are respectively provided with cold trap valves, the low vacuum pipeline and the high vacuum pipeline are respectively arranged on both sides of the cold trap and a connecting pipeline connecting the two pipelines is provided. A low vacuum connecting valve for opening/closing interconnection is provided between the low vacuum pumps, and a high vacuum connecting valve for opening/closing interconnection is provided between the connecting pipeline and the high vacuum pump.

The step 1 includes the following specific steps:

Step 1.1: Install each sample tube and quartz collection tube on the corresponding opening of the water sample collection pipeline, and block the unused opening on the water sample collection pipeline with a piston vacuum plug;

Step 1.2: Turn on the low vacuum pump, open the low vacuum connection valve, open the low vacuum valve between the low vacuum pump and the water sample collection pipeline, open the cold trap valves at both ends of the cold trap, open the high vacuum pump and the water sample collection tube Open the high-vacuum valve between the channels, open the sample burst valve on each sample tube and the water sample collection valve on each quartz collection tube in turn, and draw a low vacuum;

Step 1.3: Put each sample tube on the heating furnace and heat to 150-200 degrees Celsius to degas and remove the superficially adsorbed water;

Step 1.4: When the vacuum degree reaches below 10Pa, turn on the high vacuum pump, close the low vacuum connection valve, open the high vacuum connection valve, put a Dewar bottle filled with liquid nitrogen on the cold trap, and when the vacuum degree reaches below 0.1Pa, Close each sample burst valve and each water sample collection valve, close the low vacuum valve, the cold trap valve at both ends of the cold trap and the high vacuum valve;

Step 1.5: Heat the heating furnace to about 400 degrees Celsius to burst, open the sample burst valve on a sample tube, cover the corresponding quartz collection tube with cold liquid, and then open the water sample collection valve on the quartz collection tube to start collecting Water sample, then close the water sample collection valve;

Step 1.6: Clamp the lower end of the capillary with tweezers, and at the same time use a liquefied gas torch to quickly seal the capillary at 3-4 mm above the cold liquid, and remove the capillary where the water sample is collected after fusing.

The step 1.4 also includes: using the vacuum gauge I on the low vacuum pipeline to measure the vacuum degree in the vacuum communication pipeline when the low vacuum pump is turned on, and using the vacuum gauge II on the high vacuum pipeline to measure the vacuum degree when the high vacuum pump is turned on. Vacuum degree in the vacuum connection line.

The step 1.5 also includes: before closing the water sample collection valve, first close the sample burst valve, slightly open the low vacuum valve or high vacuum valve to extract miscellaneous gas, and close it until the reading of vacuum gauge I or vacuum gauge II no longer changes Low vacuum valve or high vacuum valve; the cold liquid includes a mixed liquid made of absolute ethanol and liquid nitrogen, and the temperature of the mixed liquid is about minus 50 degrees Celsius.

The step 2 also includes receiving the sealed capillary part with collected water samples through the sample tray of the solid autosampler and melting it by the high-temperature reaction tube to release water vapor and make it crack to generate hydrogen gas of mixed gas.

In the step 1, the sample bursting device and the water sample collection device are respectively adjacent to the openings that communicate with the water sample collection pipeline; the low vacuum pipeline, high vacuum pipeline and water sample collection pipeline are wound with The heating temperature of the heating cable is 100-200 degrees Celsius to prevent water vapor condensation in the pipeline.

The glassy carbon contained in the high-temperature reaction tube in the step 2 reacts with the water vapor to generate a mixed gas comprising carbon monoxide and hydrogen; the isotope ratio mass spectrometer and the high-temperature cracking/elemental analyzer There is also a ConFlo interface device between them, and the hydrogen gas separated by the gas chromatography column is compared with the reference hydrogen gas in the isotope ratio mass spectrometer to determine the hydrogen isotope ratio after passing through the ConFlo interface device.

Compared with the prior art, the present invention has the following advantages: since the capillary part can condense the introduced gas sample into its interior to collect the water sample in the fluid inclusion, the collected water sample can be The capillary part is input into the high-temperature pyrolysis/elemental analyzer by means of solid sample injection, and hydrogen is generated and separated through the high-temperature reaction tube and gas chromatography column, so that the isotope ratio mass spectrometer can analyze hydrogen isotopes in water To obtain the hydrogen isotope ratio, since the method of capillary part and solid sampling is adopted, compared with the method of liquid sampling, the amount of sample required is less, which can effectively save the sample amount of fluid inclusions, and can be obtained in the sample In the case of a small amount (for example, when a 3g sample cannot be selected), the prepared hydrogen meets the sample signal requirements of the subsequent mass spectrometry detection by solid sample injection, so as to accurately measure the hydrogen isotope analysis in the fluid inclusion water to obtain the hydrogen isotope ratio.     

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. Ordinary technicians can also obtain other drawings based on these drawings on the premise of not paying creative work.

Fig. 1 is a schematic structural diagram of a hydrogen isotope analysis system in fluid inclusion water according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on this The embodiments in the invention, and all other embodiments obtained by persons of ordinary skill in the art without creative effort, all belong to the scope of protection of the present invention.

In order to adapt to the limitation of actual geological sample volume (such as fluid inclusion sample volume), the present invention provides a hydrogen isotope analysis system and method in fluid inclusion water, which collects offline water samples by vacuum bursting of inclusions (here offline/online It is relative to IRMS. The sample injection under the action of the carrier gas flow through the pipeline connection is called online, and the sample injection that is not directly connected to the pipeline is called offline) and TC/EA-IRMS (TC/EA is pyrolysis/element Analyzer, the full name is Temperature Conversion/Elemental Analyzer, when TC/EA and IRMS are used together, it is written as TC/EA-IRMS) online measurement combination, and improves the traditional TC/EA-IRMS sampling method to realize hydrogen in fluid inclusion water High-precision, high-accuracy, and high-throughput analysis of isotopes.

Usually, TC/EA-IRMS needs to use liquid sampling method when measuring hydrogen isotope in water, and the liquid autosampler will pipette 0.1-0.2uL water sample from the sample bottle containing 1.0-2.0mL water sample (for example, use micro The sampling needle absorbs 0.1-0.2uL of water sample, and the capacity of the sample bottle is 2mL. Since the micro-sampling needle needs to be inserted into the sample bottle to a certain depth and ensure that the water sample is absorbed instead of air, the sample bottle needs to be filled with 1.0- 2.0mL water sample), inject into the high-temperature reaction tube of TC/EA through the sealing septum (the sealing septum here is to prevent air from entering, for example, the air leaks in during the insertion of the micro-sampling needle). The water sample is rapidly gasified at high temperature and undergoes a reduction reaction with the glassy carbon particles filled in the high-temperature reaction tube at 1350°C. The resulting _H2 and CO mixed gas is carried by the He carrier gas flow (flow rate 100mL/min) through the gas phase. The chromatographic column is separated and introduced into an isotope ratio mass spectrometer for analysis. That is to say, in fact, TC/EA-IRMS only needs 0.1~0.2uL water sample when measuring hydrogen isotope in water. If the water from the bursting of fluid inclusions can be efficiently entered into the high-temperature reaction tube of TC/EA, the required amount will be greatly reduced. Sample volume of fluid inclusions.

As shown in Figure 1, an embodiment of the present invention provides a hydrogen isotope analysis system in fluid inclusion water, including a water sample collection instrument for collecting water samples in the fluid inclusions, and a water sample collection instrument for analyzing the collected water samples. A combined TC/EA-IRMS instrument for hydrogen isotope analysis in water; the water sample collection instrument includes a vacuum communication pipeline (including pipelines composed of 90, 91 and 92), a sample burst device (including 1 and 2) and water sample collection device (including 6 and 7); the gas sample generated after the sample of the fluid inclusion is burst by the sample burst device is passed into the water sample collection device through the vacuum communication pipeline; the water sample collection The device comprises a quartz collection tube 6 formed at its lower end with a capillary section 8 for condensing the incoming gas sample into its interior to collect the water sample in the fluid inclusion ; The TC/EA-IRMS combined instrument (not shown in Fig. 1) includes pyrolysis/elemental analyzer (TC/EA) and isotope ratio mass spectrometer (IRMS), and the pyrolysis/elemental analyzer includes for Melt the capillary part where the water sample is collected to release water vapor and crack it to react to generate a high-temperature reaction tube containing a mixed gas containing hydrogen, and a gas chromatographic column for separating hydrogen from the mixed gas; the isotope ratio mass spectrometer The instrument receives the separated hydrogen and analyzes it for hydrogen isotope in water to obtain the hydrogen isotope ratio.

Here, since the capillary part can condense the introduced gas sample inside to collect the water sample in the fluid inclusion, the capillary part where the water sample is collected (for example, sealed) can be passed through a solid The way of sample injection is input into the high-temperature cracking/elemental analyzer, and the hydrogen is separated through the high-temperature reaction tube and the gas chromatographic column, so that the isotope ratio mass spectrometer can analyze the hydrogen isotope in water to obtain the hydrogen isotope ratio. Compared with the method of liquid sampling, the required sample amount is less, which can effectively save the sample amount of fluid inclusions (due to the use of solid sampling, only a small amount of sample collection is required) For example, 0.1~0.2uL water sample can meet the follow-up analysis requirements), and in the case of small sample volume (for example, when 3g sample cannot be selected), the prepared hydrogen can meet the follow-up mass spectrometry detection by solid sample injection The sample signal requirements of the sample, so as to accurately analyze the hydrogen isotope in the fluid inclusion water to obtain the hydrogen isotope ratio.

The water sample collection device also includes a cold liquid 7 that covers the capillary portion 8 and refrigerates it. The cold liquid 7 includes a mixed liquid made of absolute ethanol and liquid nitrogen, and the temperature of the mixed liquid is between Around minus 50 degrees Celsius.

Here, the cold liquid 7 can refrigerate the capillary part 8 , thereby lowering its temperature, so as to collect the gas sample produced after the sample bursting device is blown through the vacuum communication pipeline at the capillary part 8 . The cold liquid can be, for example, a mixed liquid made of absolute ethanol and liquid nitrogen, and the temperature is, for example, about minus 50 degrees Celsius, which is enough to condense the water sample entering the capillary into small ice crystals and adhere to the capillary. After a certain condensing time, it is considered that all the water released from the inclusions condenses in the capillary part. At this time, there may be other gases released from the inclusions in the capillary part (i.e. miscellaneous gases, such as carbon dioxide CO ₂ , methane CH ₄ , argon Ar, etc.), the miscellaneous gas can be sucked away by the vacuum pump (for example, slightly open the corresponding valve to connect the low vacuum pump/high vacuum pump) through the vacuum connection pipeline. For example, the quartz collection tube 6 is only covered with cold liquid at the capillary part, so that a low pressure is formed there, similar to the function of the air pump, so that the released material molecules move towards the capillary part, and the water molecules that move are all condensed at the capillary part, and Not the place with the larger pipe diameter above. The area above the capillary part can be removed by high temperature to remove impurities, and then pull out a section of the capillary part next time, and continue to use it.

The water sample collection device also includes a liquefied gas torch for fusing and sealing the capillary part, and the high-temperature reaction tube is used for receiving the capillary part that collects water samples after fusing and sealing through the sample tray of the solid autosampler. 80 melts to release water vapor and cracks it to generate a mixed gas containing hydrogen. The capillary portion 80 is about 8mm long and 0.2-0.3mm in diameter after fusing.

Here, the capillary portion 80 that collects the water sample can be melted and sealed by a liquefied gas torch, for example (for example, the high-temperature flame that can be ejected from a liquefied gas torch can fuse the quartz capillary portion and seal it again), for example, clamp the capillary portion with tweezers At the same time, use a liquefied gas torch to quickly melt and seal the capillary part at about 3-4 mm above the cold liquid 7 (at this time, the lower end of the capillary part is contained in the cold liquid 7), and remove the sealed capillary where the water sample is collected. The capillary part 80 can make the collected water sample sealed inside the capillary part 80, so as to meet the requirement of solid sampling. The diameter and length of the quartz capillary part can be determined based on, for example, the liquefied volume of the water sample and the size of a solid sample injector (eg, a solid autosampler). When fusing and sealing, for example, keep the lower part of the capillary in the cold liquid, clamp it with tweezers, and melt and sinter the upper part of the cold liquid with a liquefied gas gun. Because the capillary is very thin, it can be melted and sealed in about 1 second. At this time, the cold liquid will Volatilizes quickly, but the lower part of the cold liquid has no time for heat exchange to melt the ice crystals, ensuring that the water sample will not volatilize and cause isotope fractionation (the "isotope fractionation" here means that when a chemical reaction or state changes, it may cause isotope fractionation, so that the original material isotope ratio changes).

The sample bursting device includes a thermal bursting device, a crushing bursting device or a vacuum ball milling bursting device, and the thermal bursting device includes a sample tube 1 for containing the sample of the fluid inclusion, and the sample tube is put on and Heating furnace 2 for heating it.

Here, the sample bursting device only needs to be able to burst the sample of the fluid inclusion to release the water (often contained in the gas sample generated by the burst), for example, a thermal burst device often uses a sample tube to hold the fluid inclusion The sample is then put on a heating furnace to heat it so that it bursts to produce a gas sample. For example, you can first put the heating furnace on the sample tube and heat it to 150-200 degrees Celsius to degas (remove the surface adsorbed water of the sample), and then heat the heating furnace to about 400 degrees Celsius to burst. The temperature and time of bursting vary according to different samples. .

The vacuum communication pipeline includes a low vacuum pipeline 90 communicated with a low vacuum pump, a high vacuum pipeline 91 communicated with a high vacuum pump, and a water sample collection pipeline 92 communicated with the water sample collection instrument. At least two openings 93 communicating with the sample bursting device or the water sample collecting device are provided on the road.

The low vacuum pipeline is provided with a low vacuum valve 20 for opening/closing communication with the water sample collection pipeline, and the high vacuum pipeline is provided with a high vacuum valve 20 for opening/closing communication with the water sample collection pipeline 50. The low vacuum pipeline is also provided with a vacuum gauge I for measuring the vacuum degree in the vacuum communication pipeline, and the high vacuum pipeline is also provided with a vacuum gauge II for measuring the vacuum degree in the vacuum communication pipeline.

Here, for example, a low vacuum pump can be used to evacuate the water sample collection pipeline 92 connected with it through the low vacuum pipeline 90 (at this time, the low vacuum valve is opened and the high vacuum valve is closed, and the vacuum gauge 1 is used to monitor the vacuum communication pipeline. vacuum degree, especially the low vacuum pipeline 90 and the water sample collection pipeline 92 that communicate with each other, then use the high vacuum pump to draw a high vacuum through the high vacuum pipeline 91 to the water sample collection pipeline 92 connected to it (at this time Open the high-vacuum valve and close the low-vacuum valve, and use the vacuum gauge II to monitor the vacuum degree of the vacuum communication pipeline, especially the vacuum degree of the interconnected high-vacuum pipeline 91 and water sample collection pipeline 92), and finally make the water sample The vacuum degree of the collection pipeline 92 meets the actual requirements, so that the bursting of samples and the collection of water samples can be performed more optimally.

A sample burst valve 5 is provided between the sample burst device and the water sample collection pipeline, a water sample collection valve 9 is provided between the water sample collection device and the water sample collection pipeline, and the sample burst The device and the water sample collection device are respectively connected to the sample burst valve and the water sample collection valve through heat-shrinkable tubes.

Here, for example, the sample burst valve 5 and the water sample collection valve 9 are closed during vacuuming. When the vacuum degree in the pipeline meets the requirements, the sample burst valve 5 can be opened (the water sample collection valve 9 is closed), and the heating furnace cover can be turned on first. Heat the upper sample tube to 150-200 degrees Celsius to degas (remove the superficial adsorbed water of the sample, at this time it can be pumped out through the vacuum pump at the same time, and after a certain period of time, close the corresponding valve connected to the vacuum pump), and then heat the heating furnace to 400 Burst at about Celsius, wait for a certain period of time and then close the sample burst valve 5, and open the water sample collection valve 9, wait for the water sample collection device to collect the corresponding water samples for a period of time and then close the water sample collection valve 9, through the cooperation of these valves can More optimized implementation of sample burst and water sample collection.

The opening in the at least two openings that is not communicated with the sample bursting device or the water sample collection device is blocked with a piston vacuum plug 3, and the sample bursting device and the water sample collection device are respectively connected to the water sample collection tube. The openings communicating with the pipelines are adjacent in position; the low vacuum pipeline, the high vacuum pipeline and the water sample collection pipeline are wound with heating cables, and the heating temperature of the heating cables is 100-200 degrees Celsius to prevent condensation of water vapor in the pipelines.

Here, for example, the sample tube 1 and the quartz collection tube 6 are generally adjacent to each other as far as possible, so as to minimize the possibility of condensation to other places during the transfer of the water sample and improve the recovery rate of the water sample. For other unused pipeline openings, another sample tube and quartz collection tube can be installed (to realize parallel testing of multiple samples), and the unused openings can be plugged with piston vacuum plugs.

The water sample collection pipeline is also provided with a cold trap 4, and a Dewar bottle equipped with liquid nitrogen is placed on the cold trap 4. The openings on the water sample collection pipeline are symmetrically distributed on both sides of the cold trap. Both ends of the cold trap are respectively provided with cold trap valves (30 and 40).

Here, for example, the area from the low vacuum valve 20 to the cold trap valve 30, from the cold trap valve 40 to the high vacuum valve 50 is wrapped with a heating cable, which can be heated to 100~ 200 degrees Celsius, which makes it easier for the pipeline to obtain a lower vacuum during the process of vacuuming and water sample release and transfer, and at the same time prevents water vapor from condensing in the pipeline. Adopt the Dewar bottle that liquid nitrogen is housed on 4 sets of cold traps and can obtain high vacuum environment more easily when high vacuum pump vacuumizes, and the opening 93 that is communicated with described sample bursting device or water sample collection device is symmetrically distributed on both sides of described cold trap. For example, there are two openings on each side of the cold trap 4, and one of the two openings on each side communicates with the sample bursting device, and the other communicates with the water sample collecting device. In this way, the bursting of the fluid inclusion sample and the water sample collection process can be carried out simultaneously on the left and right sides of the cold trap 4 (for example, when the water sample collection pipeline reaches a high vacuum, close the cold trap valve 30 and the cold trap valve 40, so that the left and right ends The water sample collection pipeline is separated on the gas path), without affecting each other, and the test efficiency is improved (that is, the burst and water sample collection tests are performed in parallel without any influence on each other). Another example is that there are more than five openings on each side of the cold trap 4, two of which are respectively connected with one group of sample bursting devices and water sample collection devices (adjacent positions), and the other two openings are respectively connected with another group of The sample burst device and the water sample collection device are connected (adjacent to each other), and the other unused openings are blocked with piston vacuum plugs 3. During the test, the two sets of sample burst devices and water sample collection devices pass through the sample burst valve and the water sample collection device respectively. The water sample collection valve is controlled on and off, and the other group is closed during one group of tests (for example, after one group completes bursting, water sample collection, miscellaneous gas extraction and fusion sealing, it is vacuumed again, and then another group of tests is carried out).

There may be other gases (i.e. miscellaneous gases) released by the inclusions in the capillary part, which can be sucked away by slightly opening the corresponding valve. For example, if the explosion and collection are performed on the left side of the cold trap 4, you can slightly open the low vacuum Valve 20, makes miscellaneous gas be sucked away by low vacuum pump, closes low vacuum valve 20 again after the reading of vacuum gauge 1 no longer changes; The miscellaneous gas is sucked away by the low vacuum pump, and the high vacuum valve 50 is closed again after the reading of the vacuum gauge II no longer changes.

The glassy carbon contained in the high-temperature reaction tube undergoes high-temperature cracking reaction with the water vapor to generate a mixed gas containing carbon monoxide and hydrogen; a ConFlo is also installed between the isotope ratio mass spectrometer and the high-temperature cracking/element analyzer. An interface device, the hydrogen separated by the gas chromatographic column is compared with the reference hydrogen in the isotope ratio mass spectrometer to determine the hydrogen isotope ratio after passing through the ConFlo interface device.

Here, the ConFlo interface device is an interface accessory of IRMS, which is used to connect TC/EA and IRMS, and can, for example, add a reference gas circuit (here IRMS can have its own reference gas circuit, and the ConFlo interface device can also introduce one or more channels Reference gas path, and automatically control the ratio of sample gas and reference gas, so that the reference gas and sample gas enter the IRMS through the same gas path), so that the separated hydrogen is introduced into the isotope ratio mass spectrometer to compare with the reference hydrogen to determine Hydrogen isotope ratio (for example, hydrogen isotope ratio δ ² D, where δ ² D is a representation method of hydrogen isotope ratio, when compared with reference hydrogen, the hydrogen isotope of the gas to be measured - the δ value of deuterium D can be calculated, its Generally used to measure the difference in hydrogen isotope ratio).

More optimally, a cold trap 4 is provided on the water sample collection pipeline, and a Dewar bottle equipped with liquid nitrogen is placed on the cold trap, and the openings on the water sample collection pipeline are symmetrically distributed on both sides of the cold trap , the two ends of the cold trap 4 are respectively provided with cold trap valves (cold trap valve 30 and cold trap valve 40), and the low vacuum pipeline 90 and the high vacuum pipeline 91 are respectively arranged on both sides of the cold trap 4 and A connection pipeline 94 connecting the two pipelines is provided, and a low vacuum connection valve 10 for opening/closing mutual communication is provided between the connection pipeline and the low vacuum pump, and the connection pipeline and the high vacuum pump are connected to each other. There is a high vacuum connection valve 60 that opens/closes the mutual communication.

Here, the control mode between the low vacuum pump, the high vacuum pump and the water sample collection pipelines on the left and right sides of the cold trap 4 can be made more flexible by connecting the pipeline 94, and the low vacuum valve 10, the low vacuum valve 20, and the cold trap valve 30 and 40, the high vacuum valve 50 and the high vacuum connection valve 60 can flexibly control each pipeline in the vacuum communication pipeline separately, so that the water sample collection pipelines on the left and right sides of the cold trap 4 can simultaneously perform sample bursting And water sample collection process, so as to achieve the purpose of parallel experiment.

There may be other gases (i.e. miscellaneous gases) released by the inclusions in the capillary part 8, which can be sucked away by slightly opening the corresponding valve. Vacuum valve 20 (low vacuum connection valve 10 or high vacuum connection valve 60 is opened, and cold trap valves 30 and 40 are closed), so that the miscellaneous gas is sucked away by the low vacuum pump or high vacuum pump. Change and close the low vacuum valve 20 again; if bursting and collecting are performed on the right side of the cold trap 4, the high vacuum valve 50 can be slightly opened (the low vacuum connection valve 10 or the high vacuum connection valve 60 are opened, and the cold trap valves 30 and 40 are closed ), so that the miscellaneous gas is sucked away by the low vacuum pump or the high vacuum pump, and then close the high vacuum valve 50 after the reading of vacuum gauge I or vacuum gauge II no longer changes; The time to open the valve slightly to avoid disturbances between the two.

When the present invention analyzes the hydrogen isotope in fluid inclusion water, the working process may include, for example: first, put the weighed inclusion sample into the sample tube 1 (such as a quartz sample tube), and then put a thermal burst system or other Burst system (here other burst systems such as those constructed by crushing or vacuum ball milling, these systems can also use a similar method to collect burst water samples with a capillary). The thermal burst system is shown in Figure 1: the sample tube 1, the quartz collection tube 6, and the vacuum communication line are respectively connected to the sample burst valve 5 and the water sample collection valve 9 through heat-shrinkable tubes, and the unused lines can be used with pistons The vacuum plug 3 is sealed, and the pipelines are all wound with heating cables to prevent cooling of the water sample. After the system is vacuumed, set the heating furnace 2 on the sample tube 1 and start heating to burst the inclusions. Cover the capillary portion of the quartz collection tube 6 with cold liquid to cool and collect the released water samples. After the water sample is collected, remove the miscellaneous gas and seal the capillary. The sealed capillary (such as the quartz capillary) is about 8mm long and 0.2-0.3mm in diameter. The fusion sealing heads at both ends are slightly larger, as shown in Figure 1 Shown in 80.

Put the capillary part containing inclusion trace water in the sample tray of the solid autosampler of TC/EA and enter the high-temperature reaction tube in the way of solid sample injection. Since the temperature in the high-temperature reaction tube is as high as 1400 degrees Celsius, the capillary part will quickly Melting (for example, the composition of the capillary part is SiO2, which does not contain water and hydrogen elements, and will not affect the hydrogen isotope), the water sample will undergo a high-temperature cracking reaction with the glassy carbon in the high-temperature reaction tube in the form of water vapor to generate carbon monoxide and hydrogen, and pass through the gas phase Column GC (Gas Chromatography, the gas chromatography GC here refers to the gas chromatography column in TC/EA, which is used to separate the analyzed gas of pyrolysis/elemental analyzer) enters the mass spectrometer through the ConFlo interface device, and the reference hydrogen The comparison allows the determination of hydrogen isotope ratios.

The present invention can effectively reduce the sample amount required for hydrogen isotope analysis in inclusion water by at least one order of magnitude without affecting the precision and accuracy, and greatly reduce the difficulty of inclusion sorting.

Correspondingly, the embodiment of the present invention provides a method for analyzing hydrogen isotopes in fluid inclusion water, and an embodiment of the specific analysis process may include but not limited to the following steps:

Step 1: Use a water sample collection instrument to collect water samples in the fluid inclusions; wherein the water sample collection instrument includes a vacuum communication pipeline, a sample burst device and a water sample collection device; the sample of the fluid inclusions is passed through the The gas sample generated after the bursting of the sample bursting device is introduced into the water sample collection device through the vacuum communication pipeline; the water sample collection device includes a quartz collection tube, and the quartz collection tube is formed with a capillary part at its lower end. The capillary part condenses the introduced gas sample inside to collect the water sample in the fluid inclusion;

Step 2: Use the TC/EA-IRMS combined instrument to analyze the collected water samples for hydrogen isotope in water; wherein the TC/EA-IRMS combined instrument includes pyrolysis/elemental analyzer (TC/EA) and isotope ratio Mass spectrometer (IRMS), the high-temperature cracking/elemental analyzer includes a high-temperature reaction tube and a gas chromatographic column, and the high-temperature reaction tube is used to melt the capillary part where the water sample is collected to release water vapor and make its cracking reaction generate For the mixed gas of hydrogen, the hydrogen is separated from the mixed gas by using a gas chromatographic column; the separated hydrogen is received by the isotope ratio mass spectrometer and subjected to hydrogen isotope analysis in water to obtain the hydrogen isotope ratio.

The vacuum communication pipeline in the step 1 includes a low vacuum pipeline communicated with a low vacuum pump, a high vacuum pipeline communicated with a high vacuum pump, and a water sample collection pipeline communicated with the water sample collection instrument. The sample collection pipeline is provided with at least two openings communicating with the sample bursting device or the water sample collection device, and the sample bursting device includes a sample tube for containing the sample of the fluid inclusion, and the A furnace for heating the sample tube and heating it.

The step 1 includes the following specific steps:

Step 1.1: Install the sample tube and the quartz collection tube on the corresponding opening of the water sample collection pipeline, and block the unused opening on the water sample collection pipeline with a piston vacuum plug;

Step 1.2: Turn on the low vacuum pump, open the low vacuum valve between the low vacuum pump and the water sample collection pipeline, open the sample burst valve on the sample tube and the water sample collection valve on the quartz collection tube, and draw low vacuum;

Step 1.3: Put the heating furnace on the sample tube and heat it to 150-200 degrees Celsius to degas and remove the superficially adsorbed water;

Step 1.4: When the vacuum degree reaches below 10Pa, turn on the high vacuum pump, close the low vacuum valve, open the high vacuum valve between the high vacuum pump and the water sample collection pipeline, and close the sample burst when the vacuum degree reaches below 0.1Pa Valves, water sample collection valves and high vacuum valves;

Step 1.5: Heat the heating furnace to about 400 degrees Celsius to burst, open the sample burst valve, cover the corresponding quartz collection tube with cold liquid, then open the water sample collection valve to start collecting water samples, and then close the water sample collection valve;

Step 1.6: Hold the lower end of the capillary with tweezers, then use a liquefied gas torch to quickly seal the capillary at 3-4 mm above the cold liquid, and remove the capillary where the water sample is collected after fusing.

The step 1.4 also includes: using the vacuum gauge I on the low vacuum pipeline to measure the vacuum degree in the vacuum communication pipeline when the low vacuum pump is turned on, and using the vacuum gauge II on the high vacuum pipeline to measure the vacuum degree when the high vacuum pump is turned on. Vacuum level in the vacuum line.

The step 1.5 also includes: before closing the water sample collection valve, first close the sample burst valve, slightly open the low vacuum valve or high vacuum valve to extract miscellaneous gas, and close it until the reading of vacuum gauge I or vacuum gauge II no longer changes Low vacuum valve or high vacuum valve; the cold liquid includes a mixed liquid made of absolute ethanol and liquid nitrogen, and the temperature of the mixed liquid is about minus 50 degrees Celsius.

The step 2 also includes receiving the sealed capillary part with collected water samples through the sample tray of the solid autosampler and melting it by the high-temperature reaction tube to release water vapor and make it crack to generate hydrogen gas of mixed gas.

In the step 1, the sample bursting device and the water sample collection device are respectively adjacent to the openings that communicate with the water sample collection pipeline; the low vacuum pipeline, high vacuum pipeline and water sample collection pipeline are wound with The heating temperature of the heating cable is 100-200 degrees Celsius to prevent water vapor condensation in the pipeline.

The glassy carbon contained in the high temperature reaction tube in the step 2 reacts with the steam to generate a mixed gas comprising carbon monoxide and hydrogen by pyrolysis; A ConFlo interface device is also provided, and the hydrogen gas separated by the gas chromatographic column is compared with a reference hydrogen gas in the isotope ratio mass spectrometer to determine the hydrogen isotope ratio after passing through the ConFlo interface device.

More optimally, a cold trap is also provided on the water sample collection pipeline, and a Dewar bottle equipped with liquid nitrogen is placed on the cold trap, and the openings on the water sample collection pipeline are symmetrically distributed on both sides of the cold trap , the two ends of the cold trap are respectively provided with cold trap valves, the low vacuum pipeline and the high vacuum pipeline are respectively arranged on both sides of the described cold trap and are provided with connecting pipelines connecting the two pipelines, and the connecting A low-vacuum connection valve for opening/closing communication is provided between the pipeline and the low-vacuum pump, and a high-vacuum connection valve for opening/closing communication is provided between the connecting pipeline and the high-vacuum pump. At this time, for example, multiple groups of sample bursting devices and water sample collecting devices can be used on each side of the cold trap 4 to achieve the purpose of parallel testing. Multiple sets of sample bursting devices and water sample collection devices are respectively opened and closed through the sample burst valves and water sample collection valves on them, so as to realize the corresponding control of parallel tests.

At this point, step 1 includes the following specific steps:

Step 1.1: Install each sample tube and quartz collection tube on the corresponding opening of the water sample collection pipeline, and block the unused opening on the water sample collection pipeline with a piston vacuum plug;

Step 1.2: Turn on the low vacuum pump, open the low vacuum connection valve, open the low vacuum valve between the low vacuum pump and the water sample collection pipeline, open the cold trap valves at both ends of the cold trap, open the high vacuum pump and the water sample collection tube Open the high-vacuum valve between the channels, open the sample burst valve on each sample tube and the water sample collection valve on each quartz collection tube in turn, and draw a low vacuum;

Step 1.3: Put each sample tube on the heating furnace and heat to 150-200 degrees Celsius to degas and remove the superficially adsorbed water;

Step 1.4: When the vacuum degree reaches below 10Pa, turn on the high vacuum pump, close the low vacuum connection valve, open the high vacuum connection valve, put a Dewar bottle filled with liquid nitrogen on the cold trap, and when the vacuum degree reaches below 0.1Pa, Close each sample burst valve and each water sample collection valve, close the low vacuum valve, the cold trap valve at both ends of the cold trap and the high vacuum valve;

Step 1.5: Heat the heating furnace to about 400 degrees Celsius to burst, open the sample burst valve on a sample tube, cover the corresponding quartz collection tube with cold liquid, and then open the water sample collection valve on the quartz collection tube to start collecting Water sample, then close the water sample collection valve;

Step 1.6: Clamp the lower end of the capillary with tweezers, and at the same time use a liquefied gas torch to quickly seal the capillary at 3-4 mm above the cold liquid, and remove the capillary where the water sample is collected after fusing.

The step 1.4 also includes: using the vacuum gauge I on the low vacuum pipeline to measure the vacuum degree in the vacuum communication pipeline when the low vacuum pump is turned on, and using the vacuum gauge II on the high vacuum pipeline to measure the vacuum degree when the high vacuum pump is turned on. Vacuum level in the vacuum line.

The step 1.5 also includes: before closing the water sample collection valve, first close the sample burst valve, slightly open the low vacuum valve or high vacuum valve to extract miscellaneous gas, and close it until the reading of vacuum gauge I or vacuum gauge II no longer changes Low vacuum valve or high vacuum valve; the cold liquid includes a mixed liquid made of absolute ethanol and liquid nitrogen, and the temperature of the mixed liquid is about minus 50 degrees Celsius.

The step 2 also includes receiving the sealed capillary part with collected water samples through the sample tray of the solid autosampler and melting it by the high-temperature reaction tube to release water vapor and make it crack to generate hydrogen gas of mixed gas.

The sample bursting device and the water sample collection device in the step 1 are adjacent in position to the openings that communicate with the water sample collection pipeline respectively; the low vacuum pipeline, high vacuum pipeline, water sample collection pipeline and connection A heating cable is wound on the pipeline, and the heating temperature of the heating belt is 100-200 degrees Celsius to prevent condensation of water vapor in the pipeline.

The glassy carbon contained in the high temperature reaction tube in the step 2 reacts with the steam to generate a mixed gas comprising carbon monoxide and hydrogen by pyrolysis; A ConFlo interface device is also provided, and the hydrogen gas separated by the gas chromatographic column is compared with a reference hydrogen gas in the isotope ratio mass spectrometer to determine the hydrogen isotope ratio after passing through the ConFlo interface device.

Embodiments of the specific analysis process of the present invention, for example, may include but are not limited to the following steps:

Step 1: Close all valves, turn on the rough vacuum pump, open the rough vacuum connection valve 10, turn on the heating cable, connect the sample tube 1 and the quartz collection tube 2, plug the remaining opening with the piston vacuum plug 3, and turn on the rough vacuum Valve 20, cold trap valve 30, cold trap valve 40, high vacuum valve 50, open the sample burst valve 5 and water sample on each sample tube and quartz collection tube (for example, when multiple sample tubes and quartz collection tubes are tested at the same time) in sequence. Collect valve 9 to extract vacuum;

Step 2: Put the heating furnace 2 on each sample tube 1 and heat to 150-200 degrees Celsius to degas and remove the surface adsorbed water (here, each sample tube 1 can correspond to a heating furnace 2, or multiple samples can be The tube 1 only shares one heating furnace 2, at this time, the heating furnace 2 can be put on the sample tube 1 to be tested one by one);

Step 3: When the vacuum degree reaches below 10Pa (monitored by vacuum gauge I), turn on the high vacuum pump, close the low vacuum connection valve 10, open the high vacuum connection valve 60, and put the cold trap 4 on the trap with liquid nitrogen When the vacuum reaches below 0.1Pa (monitored by vacuum gauge II), close the sample burst valve 5 and water sample collection valve 9 on each sample tube and quartz collection tube, close the low vacuum valve 20, cold trap Valve 30, cold trap valve 40, high vacuum valve 50;

Step 4: Heat the heating furnace 2 to about 400 degrees Celsius for bursting, and the temperature and time of bursting vary according to different samples;

Step 5: Open the sample burst valve 5 on a sample tube, cover the corresponding quartz collection tube 6 with cold liquid, immerse the lower part of the capillary with the cold liquid to a depth of 3-4mm, and equilibrate for 2-3 minutes;

Step 6: Open the water sample collection valve 9 on the corresponding quartz collection tube, start to collect water vapor, equilibrate for 5-6 minutes, close the sample burst valve 5, slightly open the low vacuum valve 20, extract miscellaneous gas, and wait for the reading of the vacuum gauge II No longer change, close the low vacuum valve 20;

Step 7: Close the water sample collection valve 9, clamp the lower end of the capillary with tweezers, and at the same time use a liquefied gas gun to quickly melt and seal the capillary at about 3-4 mm above the cold liquid, and remove the sealed capillary 80 (here , the symmetrical left and right ends of the cold trap 4 can carry out parallel tests of two sets of sample tubes and quartz collection tubes at the same time, that is, step 4, step 5, step 6 and step 7 are carried out at the same time, as long as the two sets of tests are staggered to extract miscellaneous gases It is sufficient to slightly open the low vacuum valve 20 or the high vacuum valve 50 at a time);

Step 8: After a group of sample tubes and quartz collection tubes on either side of the cold trap 4 complete the process of sample bursting, water sample collection, extraction of miscellaneous gases and fusing the capillary part, the low vacuum valve 20 and the cold trap valve can be opened again 30. The cold trap valve 40 and the high vacuum valve 50 are used to extract the vacuum. After the vacuum is pumped, steps 4, 5, 6, and 7 can be repeated to realize the water flow of another group of sample tubes and quartz collection tubes on the same side of the cold trap 4. sample collection process;

Step 9: After all sample tube samples on the pipeline have collected water samples, close all valves, replace with new sample tubes and quartz collection tubes, repeat the process from step 1 to step 8, and continue the processing of the next batch of samples.

Step 10: Put the fused capillary part in the solid sampler of TC/EA, and carry out the online analysis of hydrogen isotope with automatic sampling (for example, multiple fused capillary parts of the same batch of tests can be sequentially passed through the solid automatic injection). The sampler is input into the TC/EA-IRMS combined instrument to achieve the purpose of analysis. At this time, for example, multiple hydrogen isotope ratios obtained in the same batch can be averaged, or multiple groups of hydrogen isotope ratios obtained in different batches can be compared with each other. , for in-depth analysis).

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can also be implemented through other structures, and the features of the present invention are not limited to the above preferred embodiments. Any change or modification that can be easily conceived by any person familiar with the technology within the technical field of the present invention shall be covered by the patent protection scope of the present invention.

Claims (10)

1. A hydrogen isotope analysis method in fluid inclusion water, is characterized in that, comprises the following steps: Step 1: Use a water sample collection instrument to collect water samples in the fluid inclusions; wherein the water sample collection instrument includes a vacuum communication pipeline, a sample burst device and a water sample collection device; the sample of the fluid inclusions is passed through the The gas sample generated after the bursting of the sample bursting device is introduced into the water sample collection device through the vacuum communication pipeline; the water sample collection device includes a quartz collection tube, and the quartz collection tube is formed with a capillary part at its lower end. The capillary part condenses the introduced gas sample inside to collect the water sample in the fluid inclusion; Step 2: Use the TC/EA-IRMS combined instrument to analyze the collected water samples for hydrogen isotope in water; wherein the TC/EA-IRMS combined instrument includes pyrolysis/elemental analyzer (TC/EA) and isotope ratio Mass spectrometer (IRMS), the high-temperature cracking/elemental analyzer includes a high-temperature reaction tube and a gas chromatographic column, and the high-temperature reaction tube is used to melt the capillary part where the water sample is collected to release water vapor and make its cracking reaction generate For the mixed gas of hydrogen, the hydrogen is separated from the mixed gas by using a gas chromatographic column; the separated hydrogen is received by the isotope ratio mass spectrometer and subjected to hydrogen isotope analysis in water to obtain the hydrogen isotope ratio. 2. The method according to claim 1, wherein the vacuum communication line in the step 1 comprises a low vacuum line communicated with a low vacuum pump, a high vacuum line communicated with a high vacuum pump, and a high vacuum line communicated with the high vacuum pump. A water sample collection pipeline connected to the water sample collection instrument, the water sample collection pipeline is provided with at least two openings communicating with the sample bursting device or the water sample collection device, and the sample bursting device includes A sample tube for the sample of the fluid inclusion, and a heating furnace for covering the sample tube and heating it. 3. The method according to claim 2, wherein said step 1 comprises the following specific steps: Step 1.1: Install the sample tube and the quartz collection tube on the corresponding opening of the water sample collection pipeline, and block the unused opening on the water sample collection pipeline with a piston vacuum plug; Step 1.2: Turn on the low vacuum pump, open the low vacuum valve between the low vacuum pump and the water sample collection pipeline, open the sample burst valve on the sample tube and the water sample collection valve on the quartz collection tube, and draw low vacuum; Step 1.3: Put the heating furnace on the sample tube and heat it to 150-200 degrees Celsius to degas and remove the superficially adsorbed water; Step 1.4: When the vacuum degree reaches below 10Pa, turn on the high vacuum pump, close the low vacuum valve, open the high vacuum valve between the high vacuum pump and the water sample collection pipeline, and close the sample burst when the vacuum degree reaches below 0.1Pa Valves, water sample collection valves and high vacuum valves; Step 1.5: Heat the heating furnace to about 400 degrees Celsius to burst, open the sample burst valve, cover the corresponding quartz collection tube with cold liquid, then open the water sample collection valve to start collecting water samples, and then close the water sample collection valve; Step 1.6: Hold the lower end of the capillary with tweezers, then use a liquefied gas torch to quickly seal the capillary at 3-4 mm above the cold liquid, and remove the capillary where the water sample is collected after fusing. 4. method as claimed in claim 2, it is characterized in that, also be provided with cold trap on the described water sample collection pipeline, put the Dewar bottle that liquid nitrogen is housed on the cold trap, on the described water sample collection pipeline Openings are symmetrically distributed on both sides of the cold trap, cold trap valves are respectively provided at both ends of the cold trap, the low vacuum pipeline and the high vacuum pipeline are respectively arranged on both sides of the cold trap and are connected to two The connection pipeline of the pipeline, the low vacuum connection valve for opening/closing is provided between the connection pipeline and the low vacuum pump, and the opening/closing valve is provided between the connection pipeline and the high vacuum pump. Interconnected high vacuum connection valves. 5. The method according to claim 4, wherein said step 1 comprises the following specific steps: Step 1.1: Install each sample tube and quartz collection tube on the corresponding opening of the water sample collection pipeline, and block the unused opening on the water sample collection pipeline with a piston vacuum plug; Step 1.2: Turn on the low vacuum pump, open the low vacuum connection valve, open the low vacuum valve between the low vacuum pump and the water sample collection pipeline, open the cold trap valves at both ends of the cold trap, open the high vacuum pump and the water sample collection tube Open the high-vacuum valve between the channels, open the sample burst valve on each sample tube and the water sample collection valve on each quartz collection tube in turn, and draw a low vacuum; Step 1.3: Put each sample tube on the heating furnace and heat to 150-200 degrees Celsius to degas and remove the superficially adsorbed water; Step 1.4: When the vacuum degree reaches below 10Pa, turn on the high vacuum pump, close the low vacuum connection valve, open the high vacuum connection valve, put a Dewar bottle filled with liquid nitrogen on the cold trap, and when the vacuum degree reaches below 0.1Pa, Close each sample burst valve and each water sample collection valve, close the low vacuum valve, the cold trap valve at both ends of the cold trap and the high vacuum valve; Step 1.5: Heat the heating furnace to about 400 degrees Celsius to burst, open the sample burst valve on a sample tube, cover the corresponding quartz collection tube with cold liquid, and then open the water sample collection valve on the quartz collection tube to start collecting Water sample, then close the water sample collection valve; Step 1.6: Clamp the lower end of the capillary with tweezers, and at the same time use a liquefied gas torch to quickly seal the capillary at 3-4 mm above the cold liquid, and remove the capillary where the water sample is collected after fusing. 6. the method as claimed in claim 3 or 5, is characterized in that, described step 1.4 also comprises: adopt the vacuum gauge tube 1 on the described low vacuum line to measure the vacuum degree in the described vacuum communication line when the low vacuum pump is opened , using the vacuum gauge II on the high vacuum pipeline to measure the vacuum degree in the vacuum communication pipeline when the high vacuum pump is turned on. 7. The method according to claim 3 or 5, wherein said step 1.5 further comprises: before closing the water sample collection valve, first closing the sample burst valve, slightly opening the low vacuum valve or high vacuum valve to extract miscellaneous gases , close the low vacuum valve or the high vacuum valve until the reading of vacuum gauge I or vacuum gauge II no longer changes; the cold liquid includes a mixture of absolute ethanol and liquid nitrogen, and the temperature of the mixture is below zero Around 50 degrees Celsius. 8. the method as claimed in claim 3 or 5, is characterized in that, also comprises in the described step 2 the capillary part that collects the water sample after fusing and sealing by the sample tray of solid autosampler and is heated by the high temperature. The reaction tube melts it to release water vapor and cracks it to generate a mixed gas containing hydrogen. 9. The method according to any one of claims 2-5, characterized in that the openings of the sample bursting device and the water sample collection device in the step 1 communicate with the water sample collection pipeline respectively Adjacent; the low-vacuum pipeline, the high-vacuum pipeline and the water sample collection pipeline are wound with heating cables, and the heating temperature of the heating cables is 100-200 degrees Celsius to prevent condensation of water vapor in the pipelines. 10. The method according to any one of claims 1-5, characterized in that, the glassy carbon contained in the high-temperature reaction tube described in the step 2 reacts with the high-temperature cracking of the water vapor to generate carbon monoxide and hydrogen. The mixed gas; the isotope ratio mass spectrometer and the pyrolysis/elemental analyzer are also provided with a ConFlo interface device, and the hydrogen separated by the gas chromatographic column passes through the ConFlo interface device in the isotope ratio mass spectrometer The hydrogen isotope ratio is determined by comparing it with the reference hydrogen in the instrument.