Gas sampling device, sampling method and measuring method of water isotope analyzer

Abstract

To address the technical problems of existing technologies that result in complex testing processes, low accuracy, and inability to test deuterium content in small amounts of hydrogen-containing samples and water-containing gases, as well as the inability to obtain accurate deuterium content test results when the water-containing gas is not atmospheric, this invention discloses a gas sampling device and method for a water isotope analyzer. The gas sampling device includes, in sequence, an inlet, a gas injector, an oxidation column, a gas buffer tank, a vacuum pump, and a heating device. The inlet includes a gas inlet, a hydrogen-containing sample inlet, and a water-containing sample inlet connected in parallel. The gas injector controls the amount of sample entering the device. The oxidation column oxidizes hydrogen in the hydrogen-containing sample to water. The gas buffer tank temporarily stores the sample to be tested. The heating device heats each module of the device to a predetermined temperature, and the vacuum pump evacuates the sampling channel to improve the testing accuracy of the sample.

Description

Technical Field

[0001] This invention relates to a gas sampling device and method for an analytical measuring instrument, and more particularly to a gas sampling device, sampling method and measurement method for a water isotope analyzer. Background Technology

[0002] A water isotope analyzer is an instrument based on infrared spectroscopy for measuring water isotope ratios. It is used to test the deuterium content in water and has wide applications in geology, environment, biology, medicine, energy, archaeology, and other fields. The water isotope analyzer tests water; other hydrogen-containing samples must first be converted into water before their deuterium content can be measured.

[0003] Currently, the common method for collecting hydrogen-containing samples is to first oxidize the sample into gaseous water, then collect it as liquid water, and finally test the collected liquid water using a water isotope analyzer to obtain the deuterium content in the hydrogen-containing sample. However, this method is relatively complex in its liquid water collection process and it is difficult to convert 100% of the hydrogen-containing sample into liquid water. Fractionation occurs during the oxidation and collection process, affecting the final test results. In addition, when using an isotope analyzer, the amount of liquid water collected is generally required to be on the order of milliliters. Using this collection method, the corresponding amount of hydrogen-containing sample needs to be on the order of liters. If there is only a small amount of hydrogen-containing sample, the amount of liquid water collected will be insufficient to meet the testing requirements of the isotope analyzer.

[0004] In addition, the direct atmospheric sampling method can be used to monitor the deuterium content of water in the atmosphere in real time using a water isotope analyzer. However, this method requires continuous circulation of the sampled gas, thus demanding a very large volume of air (usually on the order of cubic meters), making it impossible to test the deuterium content of small amounts of water-containing air. Furthermore, when the water-containing gas is not atmospheric but another gas, accurate deuterium content test results cannot be obtained, further hindering the testing of small amounts of water-containing gas. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problems of existing technologies, such as the complexity of the deuterium content testing process in hydrogen-containing samples, the low accuracy of test results, the inability to test the deuterium content in small amounts of hydrogen-containing samples and water-containing gases, and the inability to obtain accurate deuterium content test results when the water-containing gas is not the atmosphere. The invention provides a gas sampling device, sampling method, and measurement method for a water isotope analyzer.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A gas sampling device for a water isotope analyzer, located at the inlet of the analyzer, is characterized by the following: It includes an inlet, a gas injector, an oxidation column, a gas buffer tank, a vacuum pump, and a heating device, all connected in sequence via pipelines. The inlet includes a gas inlet, a hydrogen-containing sample inlet, and a water-containing sample inlet arranged in parallel; the outlets of the gas inlet and the hydrogen-containing sample inlet are equipped with drying units, and the connecting pipeline between the outlet of the drying unit, the outlet of the water-containing sample inlet, and the inlet of the gas sampler is equipped with a first control valve for controlling the opening and closing of the corresponding pipeline channels. The gas injector is used to control the amount of sample entering the test. Its outlet end is provided with a bypass line connected in parallel with the oxidation column. The connection between the bypass line and the lines at both ends of the oxidation column is provided with a second control valve and a third control valve, respectively, to control the opening and closing of the corresponding lines. The output end of the gas buffer tank is connected to the inlet end of the water isotope analyzer, and is used to collect the sample to be tested and transport it to the water isotope analyzer. The vacuum pump is located on the pipeline at the inlet or outlet end of the gas buffer tank; the heating device is respectively set at the position corresponding to the gas injector, oxidation column, gas buffer tank and each connecting pipeline, and is used to heat the gas injector, oxidation column, gas buffer tank and each connecting pipeline to a predetermined temperature.

[0007] Furthermore, it also includes a microsyringe for inputting standard samples; the microsyringe is located on the connecting line between the output of the gas injector and the second control valve; the heating device is also used to heat the microsyringe to a predetermined temperature.

[0008] Furthermore, a humidity sensor is installed at the outlet of the drying unit to detect the degree of dryness of the introduced gas or the sample to be tested; a hydrogen sensor is installed at the outlet of the oxidation column to detect the degree of hydrogen oxidation and the usage status of the oxidation column.

[0009] Furthermore, the drying unit is filled with a hydrogen-free desiccant; the oxidation column is filled with a hydrogen-free oxidant. Furthermore, the first control valve, the second control valve, and the third control valve are all three-way valves.

[0010] Meanwhile, the present invention also provides a gas injection method for a water isotope analyzer, which is characterized by using the gas injection device of the above-mentioned water isotope analyzer for hydrogen-containing sample injection, including the following steps: S1, adjust the first control valve, the second control valve and the third control valve respectively to connect the drying unit, the gas injector, the oxidation column and the gas buffer tank to form a sample injection channel; S2, the gas injector, oxidation column, gas buffer tank and all connecting pipelines are heated to the predetermined temperature by the heating device; S3, the sample inlet channel is evacuated by a vacuum pump; S4, flushing gas is introduced through the gas inlet to flush the sample inlet channel multiple times, and after the last flush, the sample inlet channel is evacuated again by a vacuum pump; the flushing gas is a gas that is consistent with the other components of the hydrogen-containing sample, and the other components refer to the components in the hydrogen-containing sample other than hydrogen. S5, close the inlet of the gas buffer tank, and the hydrogen-containing sample enters through the hydrogen-containing sample inlet, and then enters the oxidation column after passing through the drying unit and the gas sampler in sequence; S6. After the hydrogen-containing sample is oxidized into water by the oxidation column, open the inlet of the gas buffer tank to complete the collection of the hydrogen-containing sample. S7 opens the outlet of the gas buffer tank, allowing the hydrogen-containing sample to enter the water isotope analyzer, thus completing the sample introduction process.

[0011] Furthermore, in step S2, the predetermined temperature of the gas injector, gas buffer tank and all connecting pipelines is 40℃~150℃; the predetermined temperature of the oxidation column is 150℃~650℃.

[0012] Meanwhile, the present invention also provides a gas measurement method for a water isotope analyzer, which is characterized by employing a water isotope analyzer and a gas sampling device for a water isotope analyzer provided by the present invention, including the following steps: S1, according to the gas injection method of a water isotope analyzer according to the present invention, the injection of hydrogen-containing samples is completed; S2, The deuterium content of the hydrogen-containing sample was tested using a water isotope analyzer to obtain the test value; S3, Injection and measurement of standard samples S3.1, respectively adjust the first control valve, the second control valve and the third control valve to connect the drying unit, the gas injector, the oxidation column and the gas buffer tank to form an injection channel; S3.2, The gas injector, oxidation column, gas buffer tank and all connecting pipelines are heated to the predetermined temperature by the heating device; S3.3, The sample inlet channel is evacuated using a vacuum pump; S3.4, flushing gas is introduced through the gas inlet to flush the injection channel multiple times, and after the last flush, the injection channel is evacuated again by a vacuum pump; the flushing gas is a gas that is consistent with other components of the hydrogen-containing sample, and the other components refer to other components in the hydrogen-containing sample besides hydrogen; S3.5, close the inlet of the gas buffer tank, heat the microsyringe to the predetermined temperature, and input a standard sample with the same water volume as the hydrogen-containing sample through the microsyringe; the predetermined temperature of the microsyringe is 50℃~200℃; S3.6 After the flushing gas described in step S3.4 is introduced through the gas inlet, the inlet of the gas buffer tank is then opened, and the standard sample along with the flushing gas is collected. S3.7, close the inlet of the gas buffer tank, open the outlet of the gas buffer tank, and the standard sample enters the water isotope analyzer to complete the deuterium content test and obtain the standard value; S4, Correct the test values. Based on the standard value obtained in step S3.7, the test value obtained in step S2 is corrected by the external standard correction method to obtain an accurate test value of the deuterium content in the hydrogen-containing sample.

[0013] Meanwhile, this invention also provides another gas sampling method for a water isotope analyzer, which is characterized by using the gas sampling device of the water isotope analyzer described in this invention for water-containing sample injection, including the following steps: S1, adjust the first control valve, the second control valve and the third control valve respectively to connect the water sample inlet, the gas sampler, the bypass pipeline and the gas buffer tank to form a sample inlet channel; S2, the gas injector, gas buffer tank and all connecting pipelines are heated to a predetermined temperature by the heating device; S3, the sample inlet channel is evacuated by a vacuum pump; S4, adjust the first control valve to connect the drying unit with the gas injector, close the water sample inlet, and input flushing gas through the gas inlet to flush the sample channel multiple times. After the last flush, the sample channel is evacuated again by a vacuum pump. The flushing gas is a gas that is consistent with other components of the water sample. The other components refer to other components in the water sample besides water. S5, adjust the first control valve to open the water sample inlet and close the connection channel between the drying unit and the gas sampler. The water sample passes through the water sample inlet, the gas sampler, and the bypass pipeline in sequence and enters the gas buffer tank for collection. S6: Close the inlet of the gas buffer tank and open the outlet of the gas buffer tank. The water-containing sample enters the water isotope analyzer, thus completing the water-containing sample injection.

[0014] Meanwhile, this invention also provides another gas measurement method for a water isotope analyzer, which is characterized by employing a water isotope analyzer and a gas sampling device for a water isotope analyzer as described in this invention, including the following steps: S1, according to another gas injection method of the water isotope analyzer of the present invention, the injection of water-containing samples is completed; S2, The deuterium content of the water-containing sample was tested using a water isotope analyzer to obtain the test value; S3, Injection and measurement of standard samples S3.1, respectively adjust the first control valve, the second control valve and the third control valve to connect the drying unit, the gas injector, the bypass pipeline and the gas buffer tank to form a sample injection channel; S3.2, The gas injector, gas buffer tank and all connecting pipelines are heated to a predetermined temperature by the heating device; S3.3, The sample inlet channel is evacuated using a vacuum pump; S3.4, flushing gas is introduced through the gas inlet to flush the injection channel multiple times, and after the last flush, the injection channel is evacuated again by a vacuum pump; the flushing gas is a gas that is consistent with other components of the aqueous sample, and the other components refer to other components in the aqueous sample besides water. S3.5, heat the microsyringe to the predetermined temperature, and input a standard sample with the same water volume as the water-containing sample through the microsyringe; S3.6 After the flushing gas described in step S3.4 is introduced through the gas inlet, the inlet of the gas buffer tank is then opened, and the standard sample along with the flushing gas is collected. S3.7, close the inlet of the gas buffer tank, open the outlet of the gas buffer tank, and the standard sample enters the water isotope analyzer to complete the deuterium content test and obtain the standard value; S4, Correct the test values. Based on the standard value obtained in step S3.7, the test value obtained in step S2 is corrected by the external standard correction method to obtain an accurate test value of the deuterium content in the aqueous sample.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The gas injection device of the water isotope analyzer proposed in this invention has a simple overall structure and can be used for the injection of both hydrogen-containing and water-containing samples. When the hydrogen-containing sample is injected, the hydrogen-containing sample is oxidized and then directly injected without going through the water collection process, which makes the testing process simpler and the test results more accurate.

[0016] 2. The gas injection device for the water isotope analyzer proposed in this invention requires a hydrogen-containing sample volume as low as milliliters. Compared with the original method, the required amount of hydrogen-containing sample volume is reduced from liters to milliliters, resulting in a significant reduction in sample volume. Therefore, it is suitable for the injection and measurement of small amounts of hydrogen-containing samples.

[0017] 3. The gas injection device of the water isotope analyzer proposed in this invention allows for the direct injection of hydrogen-containing samples after oxidation, without the need for conversion into water for collection. This avoids fractionation during the conversion into water, thereby making the final test results more accurate.

[0018] 4. The gas injection device of the water isotope analyzer proposed in this invention first dries the hydrogen-containing sample through a drying unit to avoid interference from water in the hydrogen-containing sample on the test results, thereby improving the accuracy of the test results.

[0019] 5. The gas injection device of the water isotope analyzer proposed in this invention heats the gas injector, oxidation column, micro-injector and each connecting pipeline through a heating device, which can reduce the influence of adsorption on the test results and make the test results more accurate.

[0020] 6. The gas injection device of the water isotope analyzer proposed in this invention first introduces the gas into a gas buffer tank, and then into the water isotope analyzer, which makes the sample entering the water isotope analyzer more stable and the test results more accurate.

[0021] 7. The gas sampling device of the water isotope analyzer proposed in this invention has a humidity sensor installed at the outlet of the drying unit, which can monitor the degree of drying of the hydrogen-containing sample and the usage of the desiccant in the drying unit, thereby ensuring that the water in the hydrogen-containing sample is completely removed, which helps to improve the accuracy and reliability of the test results.

[0022] 8. The gas injection device of the water isotope analyzer proposed in this invention has a hydrogen sensor installed at the outlet end of the oxidation column, which can detect the degree of oxidation of hydrogen in the hydrogen-containing sample and the usage of the oxidation column, ensuring that the hydrogen in the hydrogen-containing sample is completely converted into water, thereby improving the accuracy and reliability of the test results.

[0023] 9. The gas injection device of the water isotope analyzer proposed in this invention uses a gas injector that can precisely adjust the gas injection volume. According to the composition of the hydrogen-containing sample or the water-containing sample, the gas injection volume and the injection volume of the standard sample are adjusted to ensure the consistency of the gas composition and injection volume entering the water isotope analyzer and improve the accuracy of the test.

[0024] 10. The gas injection device of the water isotope analyzer proposed in this invention is simple and reliable, multifunctional, highly integrated, easy to operate, reliable, and requires a small amount of sample.

[0025] 11. The gas measurement method for a water isotope analyzer proposed in this invention allows for the introduction of a gas with the same components as the hydrogen-containing sample into a standard sample during testing. This ensures that the gas composition and water content entering the water isotope analyzer remain unchanged, resulting in more accurate measurement results. This method can be used to test various complex hydrogen-containing samples, has a wide range of applications, and effectively solves the problem that water isotope analyzers cannot accurately test gases containing other components.

[0026] 12. The gas measurement method of the water isotope analyzer proposed in this invention allows for the interspersed testing of standard samples when testing hydrogen-containing samples, and the test results of hydrogen-containing samples can be corrected by the standard samples, making the test results more accurate.

[0027] 13. The gas measurement method of the water isotope analyzer proposed in this invention does not require gas circulation when testing water-containing samples. It can test small amounts of gas, ranging from a few milliliters to tens of milliliters. The amount of gas sample required during testing is small. Compared with existing testing methods, the amount of gas required is reduced from cubic meters to a few milliliters to tens of milliliters.

[0028] 14. The gas measurement method of the water isotope analyzer proposed in this invention allows for the input of a gas with the same composition as the water-containing sample through the gas inlet when testing water-containing samples. This ensures that the water content in the final water-containing sample remains unchanged, thereby making the final measurement results more accurate. This invention can also collect various complex water-containing gases, has a wide range of applications, and enables the injection of gases containing other components to accurately measure their deuterium content.

[0029] 15. The gas injection method for the water isotope analyzer proposed in this invention does not pass through an oxidation column when injecting water-containing samples. This not only reduces the influence of the oxidation column and improves the accuracy of the test results, but also allows for direct testing of water-containing gases containing reducing gases such as hydrogen. Furthermore, the presence of hydrogen gas will not affect the test results, making it widely applicable.

[0030] 16. The gas injection method of the water isotope analyzer proposed in this invention follows the same main path when injecting hydrogen-containing samples, water-containing samples, and their standard samples, resulting in more accurate test results.

[0031] 17. The gas measurement method of the water isotope analyzer proposed in this invention can be used to test the deuterium content in water or hydrogen-containing samples in gases with complex compositions. It has high measurement accuracy, simple method, wide applicability and good economy. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the gas sampling device of the water isotope analyzer of the present invention, according to Embodiment 1.

[0033] The attached figures are labeled as follows: 1-Gas injector, 2-Oxidation column, 3-Gas buffer tank, 4-Vacuum pump, 5-Gas inlet, 6-Hydrogen-containing sample inlet, 7-Water-containing sample inlet, 8-Drying unit, 9-First control valve, 10-Bypass pipeline, 11-Second control valve, 12-Third control valve, 13-Water isotope analyzer, 14-Micro injector. Detailed Implementation

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but these embodiments do not limit the scope of protection of the present invention in any way. It should be noted that the terms "first," "second," "third," etc., are used for descriptive purposes only and are not intended to indicate or imply their relative importance. Example

[0035] like Figure 1 As shown, this embodiment provides a gas injection device for a water isotope analyzer, which is set at the inlet end of the water isotope analyzer 13. It includes an injection port, a gas injector 1, an oxidation column 2, a gas buffer tank 3, a vacuum pump 4, and a heating device, which are connected in sequence through pipelines.

[0036] The sample inlet includes a gas inlet 5, a hydrogen-containing sample inlet 6, and a water-containing sample inlet 7, which are arranged in parallel; wherein, the gas inlet 5 is used to input a gas with the same other components as the hydrogen-containing sample or the water-containing sample.

[0037] A drying unit 8 is provided at the outlet end of both the gas inlet 5 and the hydrogen-containing sample inlet 6. In this embodiment, the drying unit 8 is a drying column filled with a hydrogen-free desiccant. The temperature of the drying unit 8 is generally not higher than room temperature, which avoids a decrease in the water adsorption capacity of the desiccant due to temperature rise, and avoids frequent replacement of the drying column, thus improving the reliability and economy of the device. A humidity sensor is installed at the outlet end of the drying unit 8 to detect the degree of dryness of the hydrogen-containing sample and the usage of the desiccant.

[0038] A first control valve 9 is provided on the connecting pipeline between the outlet end of the drying unit 8, the outlet end of the water sample inlet 7, and the inlet end of the gas sampler 1. The first control valve 9 is a three-way valve that can control the opening and closing of the hydrogen sample or water sample inlet channel.

[0039] The gas sampler 1 can precisely control the amount of gas sample entering. Its outlet pipe is equipped with a bypass pipe 10 connected in parallel with the oxidation column 2. A second control valve 11 and a third control valve 12 are respectively installed at the connection points between the bypass pipe 10 and the pipes at both ends of the oxidation column 2. These valves are used to control the opening and closing of the bypass pipe 10 or the pipes at both ends of the oxidation column 2. The second control valve 11 and the third control valve 12 are both three-way valves. The bypass pipe 10 is used to allow the injection of water-containing gases without passing through the oxidation column. This allows for direct injection and testing of water-containing gases containing reducing gases such as hydrogen, and the presence of hydrogen-containing samples will not affect the test results.

[0040] Oxidation column 2 is filled with a hydrogen-free oxidant to oxidize hydrogen-containing samples into water. A hydrogen sensor is installed at the outlet of oxidation column 2 to detect the degree of hydrogen oxidation and the operating status of oxidation column 2.

[0041] The output of the gas buffer tank 3 is connected to the inlet of the water isotope analyzer 13. This allows for the temporary collection of samples before they are transferred to the water isotope analyzer 13, resulting in more stable samples and more accurate test results. The gas buffer tank 3 is also equipped with a pressure sensor to monitor the gas pressure inside the tank in real time and to obtain the amount of gas within it.

[0042] Vacuum pump 4 is located on the pipeline at the inlet or outlet end of gas buffer tank 3. It is used to evacuate the entire device before sample injection to ensure that the sample entering the injection channel is not disturbed, thereby improving the final measurement accuracy.

[0043] This embodiment also includes a micro-injector 14 for inputting standard samples. The micro-injector 14 is located on the connecting pipeline between the output end of the gas injector 1 and the second control valve 11. The test method and injection channel of the standard sample are the same as those of the corresponding sample to be tested, so as to realize the correction of the test results of the sample to be tested.

[0044] Heating devices are respectively installed at positions corresponding to the gas injector 1, oxidation column 2, gas buffer tank 3, micro-injector 14, and each connecting pipeline, to heat the gas injector 1, oxidation column 2, gas buffer tank 3, micro-injector 14, and each connecting pipeline to predetermined temperatures. The temperature of the gas injector 1, gas buffer tank 3, and each connecting pipeline is controlled between 40℃ and 150℃, with a preferred temperature between 60℃ and 110℃. The temperature of the oxidation column 2 is controlled between 150℃ and 650℃, with a preferred temperature between 200℃ and 500℃. The temperature of the micro-injector 14 is controlled between 50℃ and 200℃, with a preferred temperature between 80℃ and 150℃.

[0045] Based on the gas injection device described above, this embodiment also provides a gas injection method for a water isotope analyzer. In this embodiment, a hydrogen-containing sample is injected, and the hydrogen-containing sample is selected as a hydrogen mixture (the balance gas is nitrogen, and the hydrogen content is about 20%). After the hydrogen mixture enters the water isotope analyzer 13, the deuterium content in the mixture is measured by the water isotope analyzer 13. The specific process is as follows: S1, adjust the first control valve 9, the second control valve 11 and the third control valve 12 respectively to connect the drying unit 8, the gas injector 1, the oxidation column 2 and the gas buffer tank 3 to form an injection channel.

[0046] S2, the gas injector 1, oxidation column 2, gas buffer tank 3, and all connecting pipelines are heated to predetermined temperatures using a heating device. Specifically, the gas injector 1, gas buffer tank 3, and all connecting pipelines are heated to 70°C; the oxidation column 2 is heated to 400°C.

[0047] S3, vacuum pump 4 is used to evacuate the sample inlet channel of step S1.

[0048] S4, nitrogen gas is introduced through gas inlet 5 to flush the injection channel of step S1 three times, and after the last flush, the injection channel is evacuated again by vacuum pump 4.

[0049] S5, close the inlet of the gas buffer tank 3, and the hydrogen mixture enters through the hydrogen-containing sample inlet 6, and then enters the oxidation column 2 after passing through the drying unit 8 and the gas sampler 1 in sequence.

[0050] S6, approximately 3 seconds later, the hydrogen mixture is oxidized into water-containing nitrogen gas by the oxidation column 2, and the inlet of the gas buffer tank 3 is opened, allowing the water-containing nitrogen gas to enter the gas buffer tank 3 and be collected.

[0051] S7, close the inlet of gas buffer tank 3, open the outlet of gas buffer tank 3, and the collected water-containing nitrogen gas enters the water isotope analyzer 13, thereby completing the injection of a hydrogen mixture.

[0052] By repeating steps S5 to S7 eight times, continuous injection of the hydrogen mixture can be achieved. If it is necessary to inject and measure hydrogen-containing gases with different components, the procedure of steps S1 to S7 can be followed. In this case, the flushing gas should be a gas with the same other components as the hydrogen-containing gas to be measured.

[0053] Furthermore, this embodiment also provides a gas measurement method for a water isotope analyzer, specifically including the following steps: S1. The hydrogen mixture is introduced according to the gas injection method of the water isotope analyzer described in this embodiment.

[0054] S2, the deuterium content of the injected hydrogen mixture was tested using a water isotope analyzer 13, and the test value was obtained.

[0055] S3, Inject and measure the standard sample, where the standard sample is the same volume of water as the hydrogen gas mixture. The specific method is as follows: S3.1, adjust the first control valve 9, the second control valve 11 and the third control valve 12 respectively to connect the drying unit 8, the gas injector 1, the oxidation column 2 and the gas buffer tank 3 to form an injection channel.

[0056] S3.2, the gas injector 1, oxidation column 2, gas buffer tank 3, and all connecting pipelines are heated to predetermined temperatures using a heating device. Specifically, the gas injector 1, gas buffer tank 3, and all connecting pipelines are heated to 70°C; the oxidation column 2 is heated to 400°C.

[0057] S3.3, Vacuum pump 4 is used to evacuate the sample inlet channel of step S3.1.

[0058] S3.4, Nitrogen gas is introduced through the gas inlet 5 to flush the injection channel of step S3.1 three times, and after the third flush, the injection channel is evacuated again by the vacuum pump 4.

[0059] S3.5, close the inlet of the gas buffer tank 3, heat the microsyringe 14 to 70°C, and input 1 μL of standard sample through the microsyringe 14.

[0060] S3.6, open the gas inlet 5 to input nitrogen gas. Since the micro-syringe 14 only injects standard water sample, it needs to be diluted with nitrogen gas to be consistent with the hydrogen-containing sample. After inputting about 5 mL of nitrogen gas, open the inlet of the gas buffer tank 3 to complete the collection of standard sample.

[0061] S3.7, close the inlet of gas buffer tank 3 and open the outlet of gas buffer tank 3. The standard sample enters the water isotope analyzer 13. The water isotope analyzer 13 tests the deuterium content of the injected standard sample to obtain the standard value.

[0062] By repeating steps S3.5 to S3.7 eight times, continuous injection and measurement of standard samples can be achieved.

[0063] S4, Correct the test values: Based on the standard value obtained in step S3.7, the test value obtained in step S2 is corrected by the external standard correction method to obtain an accurate test value of the deuterium content in the hydrogen-containing sample.

[0064] The test results show that the difference between the measured result of the deuterium content in the hydrogen mixture after correction and the corresponding standard sample measurement result is about 0.05%, which is within the uncertainty range of the measurement method. Example

[0065] This embodiment uses the same gas injection device of the water isotope analyzer as in Embodiment 1.

[0066] This embodiment provides a method for injecting water-containing samples. The water-containing sample in this embodiment is water-containing nitrogen gas, which is obtained by humidifying and drying nitrogen gas with a water sample of known deuterium content. After humidification, the water vapor content is approximately 10%. The specific process is as follows: S1, adjust the first control valve 9, the second control valve 11 and the third control valve 12 respectively to connect the water sample inlet 7, the gas sampler 1, the bypass pipeline 10 and the gas buffer tank 3 to form a sample introduction channel.

[0067] S2, the gas injector 1, gas buffer tank 3 and each connecting pipeline are heated to 70°C by the heating device.

[0068] S3, vacuum pump 4 is used to evacuate the sample inlet channel of step S1.

[0069] S4, adjust the first control valve 9 to connect the drying unit 8 with the gas injector 1, close the water sample inlet 7, and input nitrogen gas through the gas inlet 5 to flush the injection channel of step S1 3 times. After the third flush, the injection channel is evacuated by the vacuum pump 4.

[0070] S5, adjust the first control valve 9 again to open the water sample inlet 7 and close the connection channel between the drying unit 8 and the gas sampler 1. Approximately 12.4 mL of water-containing nitrogen gas is introduced through the water sample inlet 7. The water-containing nitrogen gas passes through the gas sampler 1 and the bypass pipeline 10 in sequence and is collected in the gas buffer tank 3.

[0071] S6, close the inlet of gas buffer tank 3 and open the outlet of gas buffer tank 3. The water-containing nitrogen gas in gas buffer tank 3 enters the water isotope analyzer 13, thus completing one water-containing nitrogen gas injection.

[0072] Repeat steps S5 to S6 eight times. If other water-containing gases need to be injected, follow steps S1 to S6. The rinsing gas should be the same as the other components of the water-containing gas to be tested.

[0073] Meanwhile, this embodiment also provides a gas measurement method for a water isotope analyzer, using a water isotope analyzer 13 and the gas sampling device of the water isotope analyzer of this embodiment, including the following steps: S1. According to the gas injection method of the water isotope analyzer described in this embodiment, the injection of water-containing nitrogen gas is completed.

[0074] S2, the deuterium content in water-containing nitrogen gas was tested using a water isotope analyzer 13, and the test value was obtained.

[0075] S3, Inject and measure the standard sample, where the standard sample is water with the same volume as the nitrogen gas containing water. The specific method is as follows: S3.1, adjust the first control valve 9, the second control valve 11 and the third control valve 12 respectively to connect the drying unit 8, the gas injector 1, the bypass pipeline 10 and the gas buffer tank 3 to form a sample injection channel.

[0076] S3.2, The gas injector 1, gas buffer tank 3 and each connecting pipeline are heated to 70°C by the heating device.

[0077] S3.3, Vacuum pump 4 is used to evacuate the sample inlet channel of step S3.1; S3.4, Nitrogen gas is introduced through the gas inlet 5 to flush the injection channel of step S3.1 three times, and after the third flush, the injection channel is evacuated again by the vacuum pump 4.

[0078] S3.5, heat the microsyringe 14 to 70°C, and input 1 μL of standard sample through the microsyringe 14. At the same time, introduce about 11.2 mL of nitrogen gas through the gas inlet 5. The standard sample is then collected in the gas buffer tank 3 through the bypass line 10.

[0079] S3.6, close the inlet of the gas buffer tank 3 and open the outlet of the gas buffer tank 3. The standard sample enters the water isotope analyzer 13. The water isotope analyzer 13 tests the deuterium content of the injected standard sample to obtain the standard value.

[0080] By repeating steps S3.5 to S3.6 eight times, continuous injection and measurement of standard samples can be achieved.

[0081] S4, Correct the test values: Based on the standard value of deuterium content in the standard sample obtained in step S3.6, the test value of deuterium content in water-containing nitrogen obtained in step S2 is corrected by the external standard correction method, thereby obtaining the accurate test value of deuterium content in water-containing nitrogen.

[0082] The test results show that the difference between the corrected measurement result of the deuterium content of hydrogen in water-containing nitrogen and the test result of the standard sample is about 0.1%, which is within the uncertainty range of the measurement method.

[0083] In the gas sampling method of this invention, for hydrogen-containing samples, water is first removed from the gas and the gas is quantified. Then, 100% of the hydrogen in the hydrogen-containing sample is converted into water, which is then directly injected into a water isotope analyzer for testing after quantification. Standard samples are interspersed during sample testing to correct the test results. Since there is no water collection process, fractionation introduced by this process is avoided, and since there is no liquid water collection process, the required sample volume is small.

[0084] For water-containing gases, after quantification, they are directly fed into a water isotope analyzer for testing, with standard samples interspersed during the sample testing process to correct the test results. Since gas circulation is not required, the amount of sample needed is small.

Claims

1. A gas sampling device for a water isotope analyzer, disposed at the inlet end of the water isotope analyzer (13), characterized in that: It includes an inlet, a gas injector (1), an oxidation column (2), a gas buffer tank (3) connected in sequence by pipelines, a vacuum pump (4), a micro-injector (14), and a heating device; The inlet includes a gas inlet (5), a hydrogen-containing sample inlet (6), and a water-containing sample inlet (7) arranged in parallel. The outlets of the gas inlet (5) and the hydrogen-containing sample inlet (6) are provided with a drying unit (8). A first control valve (9) is provided on the connecting pipeline between the outlet of the drying unit (8), the outlet of the water-containing sample inlet (7), and the inlet of the gas sampler (1) to control the opening and closing of the corresponding pipeline channels. The gas injector (1) is used to control the amount of sample to be tested. A bypass pipe (10) is provided on the pipeline at its outlet end, which is connected in parallel with the oxidation column (2). A second control valve (11) and a third control valve (12) are respectively provided at the connection between the bypass pipe (10) and the pipelines at both ends of the oxidation column (2) to control the opening and closing of the corresponding pipeline channels. The output end of the gas buffer tank (3) is connected to the inlet end of the water isotope analyzer (13) to collect the sample to be tested and transport it to the water isotope analyzer (13); The vacuum pump (4) is located on the pipeline at the inlet or outlet of the gas buffer tank (3); The micro-injector (14) is used to input standard samples and is located on the connecting pipeline between the output end of the gas injector (1) and the second control valve (11); The heating devices are respectively installed at positions corresponding to the gas injector (1), oxidation column (2), gas buffer tank (3), micro-injector (14) and each connecting pipeline, and are used to heat the gas injector (1), oxidation column (2), gas buffer tank (3), micro-injector (14) and each connecting pipeline to a predetermined temperature.

2. The gas sampling device of the water isotope analyzer according to claim 1, characterized in that: The outlet end of the drying unit (8) is equipped with a humidity sensor to detect the degree of dryness of the gas introduced or the sample to be tested; the outlet end of the oxidation column (2) is equipped with a hydrogen sensor to detect the degree of oxidation of hydrogen and the usage status of the oxidation column (2).

3. The gas sampling device of the water isotope analyzer according to claim 2, characterized in that: The drying unit (8) is filled with a hydrogen-free desiccant; the oxidation column (2) is filled with a hydrogen-free oxidant.

4. The gas sampling device of the water isotope analyzer according to claim 3, characterized in that: The first control valve (9), the second control valve (11) and the third control valve (12) are all three-way valves.

5. A gas sampling method for a water isotope analyzer, characterized in that, Using the gas injection device of the water isotope analyzer according to any one of claims 1-4 for hydrogen-containing sample injection, the following steps are included: S1, adjust the first control valve (9), the second control valve (11) and the third control valve (12) respectively to connect the drying unit (8), the gas injector (1), the oxidation column (2) and the gas buffer tank (3) to form an injection channel; S2, the gas injector (1), oxidation column (2), gas buffer tank (3) and all connecting pipelines are heated to a predetermined temperature by the heating device; S3, the sample inlet channel is evacuated by vacuum pump (4); S4, flushing gas is introduced through the gas inlet (5) to flush the sample inlet channel multiple times, and after the last flush, the sample inlet channel is evacuated again by the vacuum pump (4); the flushing gas is a gas that is consistent with other components of the hydrogen-containing sample, and the other components refer to other components in the hydrogen-containing sample besides hydrogen; S5, close the inlet of the gas buffer tank (3), and the hydrogen-containing sample enters through the hydrogen-containing sample inlet (6), and enters the oxidation column (2) after passing through the drying unit (8) and the gas injector (1); S6. After the hydrogen-containing sample is oxidized into water by the oxidation column (2), open the inlet of the gas buffer tank (3) to complete the collection of the hydrogen-containing sample. S7, open the outlet of the gas buffer tank (3), and the hydrogen-containing sample enters the water isotope analyzer (13), thus completing the injection of the hydrogen-containing sample.

6. The gas sampling method for the water isotope analyzer according to claim 5, characterized in that: In step S2, the predetermined temperature of the gas injector (1), the gas buffer tank (3) and all connecting pipelines is 40℃~150℃; the predetermined temperature of the oxidation column (2) is 150℃~650℃.

7. A gas measurement method for a water isotope analyzer, characterized in that, Using a water isotope analyzer (13) and the gas injection device of the water isotope analyzer according to any one of claims 1-4, the method includes the following steps: S1, according to the gas injection method of the water isotope analyzer according to claim 5 or 6, the injection of hydrogen-containing sample is completed; S2, the deuterium content of the hydrogen-containing sample was tested using a water isotope analyzer (13) to obtain the test value; S3, Injection and measurement of standard samples S3.1, adjust the first control valve (9), the second control valve (11) and the third control valve (12) respectively to connect the drying unit (8), the gas injector (1), the oxidation column (2) and the gas buffer tank (3) to form an injection channel; S3.2, the gas injector (1), oxidation column (2), gas buffer tank (3) and all connecting pipelines are heated to a predetermined temperature by the heating device; S3.3, the sample inlet channel is evacuated by vacuum pump (4); S3.4, flushing gas is introduced through the gas inlet (5) to flush the sample inlet channel multiple times, and after the last flush, the sample inlet channel is evacuated again by the vacuum pump (4); the flushing gas is a gas that is consistent with other components of the hydrogen-containing sample, and the other components refer to other components in the hydrogen-containing sample besides hydrogen. S3.5, close the inlet of the gas buffer tank (3), heat the micro-syringe (14) to the predetermined temperature, and input the standard sample with the same amount of water as the hydrogen-containing sample through the micro-syringe (14); the predetermined temperature of the micro-syringe (14) is 50℃~200℃. S3.6 After the flushing gas described in step S3.4 is input through the gas inlet (5), the inlet of the gas buffer tank (3) is opened, and the standard sample is collected along with the flushing gas. S3.7, close the inlet of the gas buffer tank (3), open the outlet of the gas buffer tank (3), the standard sample enters the water isotope analyzer (13) and completes the test of deuterium content to obtain the standard value; S4, Correct the test values. Based on the standard value obtained in step S3.7, the test value obtained in step S2 is corrected by the external standard correction method to obtain an accurate test value of the deuterium content in the hydrogen-containing sample.

8. A gas sampling method for a water isotope analyzer, characterized in that, Using the gas injection device of the water isotope analyzer according to any one of claims 1-4 for water-containing sample injection, the method includes the following steps: S1, adjust the first control valve (9), the second control valve (11) and the third control valve (12) respectively to connect the water sample inlet (7), the gas injector (1), the bypass pipeline (10) and the gas buffer tank (3) to form a sample inlet channel; S2, the gas injector (1), gas buffer tank (3) and all connecting pipelines are heated to a predetermined temperature by the heating device; S3, the sample inlet channel is evacuated by vacuum pump (4); S4, adjust the first control valve (9) to connect the drying unit (8) with the gas injector (1), close the water sample inlet (7), and input flushing gas through the gas inlet (5) to flush the sample channel multiple times. After the last flush, the sample channel is evacuated again by the vacuum pump (4). The flushing gas is a gas that is consistent with other components of the water sample. The other components refer to other components in the water sample besides water. S5, adjust the first control valve (9) to open the water sample inlet (7) and close the connection channel between the drying unit (8) and the gas injector (1). The water sample passes through the water sample inlet (7), the gas injector (1), and the bypass pipeline (10) in sequence and is collected in the gas buffer tank (3). S6, close the inlet of the gas buffer tank (3) and open the outlet of the gas buffer tank (3), so that the water sample enters the water isotope analyzer (13) and thus completes the injection of the water sample.

9. A gas measurement method for a water isotope analyzer, characterized in that, Using a water isotope analyzer (13) and the gas injection device of the water isotope analyzer according to any one of claims 1-4, the method includes the following steps: S1, according to the gas injection method of the water isotope analyzer as described in claim 8, the injection of water-containing samples is completed; S2, the deuterium content of the water-containing sample was tested using a water isotope analyzer (13) to obtain the test value; S3, Injection and measurement of standard samples S3.1 Adjust the first control valve (9), the second control valve (11) and the third control valve (12) respectively to connect the drying unit (8), the gas injector (1), the bypass pipeline (10) and the gas buffer tank (3) to form a sample injection channel; S3.2, The gas injector (1), gas buffer tank (3) and all connecting pipelines are heated to a predetermined temperature by the heating device; S3.3, the sample inlet channel is evacuated by vacuum pump (4); S3.4, flushing gas is introduced through the gas inlet (5) to flush the sample inlet channel multiple times, and after the last flush, the sample inlet channel is evacuated again by the vacuum pump (4); the flushing gas is a gas that is consistent with other components of the water-containing sample, and the other components refer to other components in the water-containing sample besides water; S3.5, heat the microsyringe (14) to a predetermined temperature, and input a standard sample with the same water content as the water-containing sample through the microsyringe (14); S3.6 After the flushing gas described in step S3.4 is input through the gas inlet (5), the inlet of the gas buffer tank (3) is opened, and the standard sample is collected along with the flushing gas. S3.7, close the inlet of the gas buffer tank (3), open the outlet of the gas buffer tank (3), and the standard sample enters the water isotope analyzer (13) and completes the test of deuterium content to obtain the standard value; S4, Correct the test values. Based on the standard value obtained in step S3.7, the test value obtained in step S2 is corrected by the external standard correction method to obtain an accurate test value of the deuterium content in the aqueous sample.

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