Carbonate double cluster isotope sample preparation device, preparation method and detection system

Abstract

The application relates to a carbonate double-cluster isotope sample preparation device, a preparation method and a detection system in the technical field of stable isotope detection, which comprises an automatic sample acidolysis reactor, a balanced gas quartz tube breaking device, a purification unit and a collection unit; a first low-vacuum pumping unit for purifying the automatic sample acidolysis reactor or the balanced gas quartz tube breaking device, a second low-vacuum pumping unit and a high-vacuum pumping unit for purifying the purification unit or the collection unit, and the automatic sample acidolysis reactor can pre-store two or more samples and sequentially perform acidolysis reaction on the samples. The carbonate double-cluster isotope sample preparation device, the preparation method and the detection system can realize full-automatic sample preparation, save manpower, reduce human errors and errors, and improve sample output rate.

Description

Technical Field

[0001] This application relates to the field of stable isotope detection technology, and in particular to a carbonate dual-cluster isotope sample preparation device, preparation method and detection system. Background Technology

[0002] Carbonate bicluster isotope analysis is based on traditional carbon and oxygen isotope analysis techniques. It involves the acid hydrolysis of carbonates with phosphoric acid to produce CO2 gas, followed by stable isotope mass spectrometry analysis of the heavy isotopes in the CO2 gas. 13 C- 18 O- 16 O (mass number 47 molecules) or 12 C- 18 O- 18 O (mass number 48 molecules) represents the degree of aggregation of carbon and oxygen isotopes when they are randomly distributed among their molecules. According to thermodynamic principles, the composition of carbonate bicluster isotopes is related to the carbonate formation temperature. Currently, thanks to previous research, empirical correction equations have been established for carbonate bicluster isotopes Δ47 and Δ48 and temperature. These equations allow for accurate reconstruction of paleotemperatures. Furthermore, this method overcomes the uncertainties introduced by traditional carbonate oxygen isotope thermometers, which require assumptions about the oxygen isotope composition of the ancient parent water. Therefore, this method is widely used in quantitative reconstruction of paleohythmia, paleotemperature and paleoclimate reconstruction, stratigraphic thermal history studies, paleovertebrate physiology, and environmental temperature research.

[0003] The preparation and pretreatment of carbonate samples are crucial for obtaining accurate bicluster isotopic compositions. Existing technologies primarily employ offline manual preparation, with offline sample preparation systems often using glass or stainless steel tubing. Significant differences in the bicluster isotopic compositions of the same sample obtained from different laboratories are mainly due to variations in offline preparation systems, cumbersome processes (often requiring over two hours to prepare a single sample), and inconsistent preparation methods across laboratories. Manual operation inevitably introduces human error and inconsistencies, resulting in poor reproducibility. All of these factors affect the accuracy of bicluster isotope Δ47 and Δ48 measurements. Furthermore, manual offline sample preparation systems can only prepare 4-5 samples per day, consuming significant manpower and exhibiting low efficiency, making it difficult to meet the demands of large-scale sample analysis in laboratories. Therefore, developing a fully automated carbonate bicluster isotope sample preparation system and its associated method is essential to meet the testing needs of those skilled in the art.

[0004] Therefore, this invention is proposed. Summary of the Invention

[0005] In view of the problems existing in the background art, this application provides a fully automated carbonate dual-cluster isotope sample preparation device and method, which can save manpower, reduce human error and error, improve sample output, reduce laboratory queuing time, and meet the testing needs of those skilled in the art.

[0006] According to a first aspect of the present invention, a carbonate dual-cluster isotope sample preparation apparatus is provided, comprising: an automatic sample acidification reactor, a quartz tube breaking device for equilibrium gas, a purification unit, and a collection unit; and a first low-vacuum pumping unit for purifying the automatic sample acidification reactor or the quartz tube breaking device for equilibrium gas, a second low-vacuum pumping unit and a high-vacuum pumping unit for purifying the purification unit or the collection unit, wherein the automatic sample acidification reactor is capable of pre-storing two or more samples and sequentially performing acidification reactions on the samples; wherein the automatic sample acidification reactor is connected to the purification unit via a fourth valve, a first valve and a second valve are introduced in parallel between the outlet end of the automatic sample acidification reactor and the inlet end of the fourth valve, the first low-vacuum pumping unit is connected to the automatic sample acidification reactor via the second valve, and the quartz tube breaking device for equilibrium gas is connected to the first low-vacuum pumping unit via the first valve; the purification unit and the collection unit are connected via a thirteenth valve and a sixteenth valve connected in series, and a connection is established between the thirteenth valve and the sixteenth valve. The purification unit comprises a cold trap 1, an eighth valve, a sulfur trap, a Porapak trap, an eleventh valve, and a second cold trap, connected in parallel from the fourth valve to the thirteenth valve. A sixth valve and a seventh valve are connected in parallel between the first cold trap and the eighth valve. The second low-vacuum pumping unit is connected to the purification unit via the sixth valve, and the high-vacuum pumping unit is connected to the purification unit via the seventh valve. A first helium inlet, controlled by a fifth valve, is introduced between the fourth valve and the first cold trap. A first helium outlet, controlled by a twelfth valve, is introduced between the second cold trap and the thirteenth valve. A second helium inlet, controlled by a tenth valve, is introduced between the Porapak trap and the eleventh valve. A second helium outlet, controlled by a ninth valve, is introduced between the eighth valve and the sulfur trap. All valves are automatically controlled.

[0007] By using the fully automated carbonate dual-cluster isotope sample preparation device in this technical solution, online automated acidolysis of carbonate samples in a phosphoric acid bath can be achieved. The generated CO2 gas, after automatic removal of impurities such as water, sulfides, and organic matter, is purified and collected in the collection unit, and directly introduced into a gas stable isotope mass spectrometer for dual-cluster isotope measurement. Simultaneously, the equilibrium gas required for dual-cluster isotope calibration data can also enter the preparation device through a quartz tube breaking device, undergo the same preparation and purification process as the sample gas, and finally enter the mass spectrometer for dual-cluster isotope measurement. This sample preparation device has a higher vacuum degree and is cleaner in removing water and pump oil, effectively solving the problems existing in traditional offline sample preparation systems.

[0008] In some embodiments of the present invention, the first low-vacuum pumping unit includes a third valve and a first mechanical pump connected in series with the second valve. The outlet end of the second valve is connected to the inlet end of the first mechanical pump through a coarse-pumping pipeline. The inner diameter of the coarse-pumping pipeline is smaller than the inner diameter of the main pipeline connecting the second valve, the third valve, and the first mechanical pump in series. A first Pirani gauge is introduced into the inlet end of the first mechanical pump, and the opening of the third valve is controlled based on the detection result of the first Pirani gauge.

[0009] In some embodiments of the present invention, the high vacuum pumping unit includes a high vacuum pump, the seventh valve and the fifteenth valve are connected in parallel to the inlet end of the high vacuum pump, and a cold trap three is connected in series at the outlet end of the seventh valve; a Penning gauge is introduced at the inlet end of the high vacuum pump.

[0010] In some embodiments of the present invention, a second Pirani gauge is introduced at the outlet end of the fourth valve; and a third Pirani gauge is introduced at the outlet end of the thirteenth valve.

[0011] In some embodiments of the present invention, a particulate filter is connected to the outlet end of the automatic sample acidification reactor, the outlet end of the balance gas quartz tube breaking device, the inlet end of the sulfur trap, the inlet and outlet ends of the Porapak trap, the outlet end of the fifth valve, and the outlet end of the tenth valve.

[0012] In some embodiments of the present invention, the sample preparation apparatus further includes a first automatic temperature control system, which is used for cooling or heating the first cold trap, the Porapak trap, or the second cold trap, and the temperature control range of the first automatic temperature control system is -185°C to 200°C.

[0013] In some embodiments of the present invention, the collection unit includes a micro-cooling finger and a second automatic temperature control system, the second automatic temperature control system being used for cooling or heating the micro-cooling finger to freeze carbon dioxide gas, thaw carbon dioxide gas, or heat and clean the micro-cooling finger.

[0014] In some embodiments of the present invention, the automatic sample acidolysis reactor includes a phosphoric acid bottle, the top opening of which is sealed to a sample turntable via a pipe. The sample turntable is used to pre-store samples and release them into the phosphoric acid bottle through the pipe. A heating jacket is fitted over the lower part of the phosphoric acid bottle, and a magnetic heating stirrer is provided at the bottom of the phosphoric acid bottle. The magnetic heating stirrer and the heating jacket automatically control the temperature inside the phosphoric acid bottle within a range of 20°C to 400°C.

[0015] According to a second aspect of the present invention, a method for preparing carbonate dual-cluster isotope samples using the above-described carbonate dual-cluster isotope sample preparation apparatus is provided, characterized by comprising the following steps:

[0016] First, the automated sample acidolysis reactor or the equilibrium gas quartz tube breaking device is purified using the first low-vacuum pumping unit. Then, the pre-stored sample is reacted using the automated sample acidolysis reactor or the equilibrium gas quartz tube is broken. The reaction products or equilibrium gas are purified online in real time by the purification unit and then enter the collection unit. They are then passed into a stable isotope mass spectrometer for dual-cluster isotope measurement. Afterward, the purification unit and the collection unit are vacuum-cleaned using the second low-vacuum pumping unit and the high-vacuum pumping unit. The automated sample acidolysis reactor or the equilibrium gas quartz tube breaking device is then purified again using the first low-vacuum pumping unit to prepare the automated sample acidolysis reactor for reacting and purifying the next sample.

[0017] According to a third aspect of the present invention, a carbonate dual-cluster isotope detection system is provided, comprising the above-described carbonate dual-cluster isotope sample preparation apparatus and a stable isotope mass spectrometer connected to the outlet end of the collection unit.

[0018] Compared with the prior art, the present invention achieves the following technical effects:

[0019] 1. The automatic sample acid hydrolysis reactor and the equilibrium gas quartz tube breaking device are connected in parallel, and they are connected in series with the purification unit and the collection unit respectively. This allows for sequential reaction and purification of samples. On the same preparation system, the equilibrium gas used to correct sample data, including 1000℃ high-temperature gas and 25℃ equilibrium gas, can be processed under the same preparation and purification conditions to ensure the consistency of data correction.

[0020] 2. A low-vacuum pump (first mechanical pump) specifically designed for purifying the automated sample acidolysis reactor and the quartz tube breaking device for the equilibrium gas, and a high-vacuum pump and a low-vacuum pump (second mechanical pump) specifically designed for purifying the purification and collection units, can automatically control the pumping of high and low vacuum, saving time and improving the efficiency of sample preparation. Specifically, a liquid nitrogen cold trap is added upstream of the high-vacuum pump. During sample processing, this cold trap is immersed in a Dewar flask liquid nitrogen cooling device, which can better remove water from the high-vacuum pipeline, increasing the vacuum level of the high-vacuum pipeline. The vacuum level of the preparation system can reach <10. -5 mBar~10 -6 mBar prevents oil backflow from the vacuum pump and prevents isotopic exchange reactions between CO2 gas and water, thereby resetting the composition of the bicluster isotopes and improving the accuracy of the experiment.

[0021] 3. The automatic sample acid hydrolysis reactor can hold 40 samples at the same time. The motor can automatically control the samples to fall into the phosphoric acid bottle in sequence for a common acid bath reaction. The lower part of the phosphoric acid bottle has a polytetrafluoroethylene sleeve with an internal heating mesh, and the bottom is a magnetic heating stirrer, which ensures precise adjustment of the acid hydrolysis reaction temperature. The temperature control range is from ambient temperature to 400℃, and the acid hydrolysis temperature can be automatically adjusted by software.

[0022] 4. At the connection points of the automatic sample acidification reactor and the balance gas quartz tube breaking device to the vacuum pipeline, 60-micron particle filters are connected upstream of the sulfur trap and upstream and downstream of the Porapak trap, respectively. These filters can prevent carbonate sample powder, glass fragments, or quartz fibers from entering the vacuum pipeline and clogging the pneumatic valves, thus extending the valve's service life and keeping the pipeline clean.

[0023] 5. The first automatic temperature control system of Cold Trap 1, Porapak Trap, and Cold Trap 2 can automatically control the required freezing and heating temperatures of the cold traps by adjusting the liquid nitrogen level and the heating temperature of the resistance wire, so as to achieve the required set temperature. The temperature control range is -185~200℃.

[0024] 6. The automatic temperature control system for the micro-cooling finger uses a peristaltic pump capable of vacuuming and a heating resistance wire to quickly lower the temperature of the micro-cooling finger to -185℃. It can also quickly heat the finger to freeze CO2 gas or release CO2 gas for heating and cleaning.

[0025] 7. The micro-cooling finger is made of stainless steel with a thin glass liner, which can better remove trace amounts of water from the micro-cooling finger and facilitate accurate measurement of the Δ48 composition with lower content. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0027] Figure 1 A schematic diagram of the fully automated carbonate dual-cluster isotope sample preparation device provided by the present invention;

[0028] Figure 2 This is a schematic diagram of the automatic temperature control system for the cold trap provided by the present invention.

[0029] The labels in the attached diagram are as follows:

[0030] 1. First valve; 2. Second valve; 3. Third valve; 4. Fourth valve; 5. Fifth valve; 6. Sixth valve; 7. Seventh valve; 8. Eighth valve; 9. Ninth valve; 10. Tenth valve; 11. Eleventh valve; 12. Twelfth valve; 13. Thirteenth valve; 14. Fourteenth valve; 15. Fifteenth valve; 16. Sixteenth valve; 17. Phosphoric acid bottle; 18. Sample turntable; 19. Heating jacket; 20. Magnetic heating stirrer; 21. Balance gas quartz tube; 22. Cold trap one; 23. Sulfur trap; 24. Porapak trap; 25. Cold trap two; 26. First helium inlet; 27. First helium outlet; 28. Second helium inlet; 29. ​​Second helium outlet; 30. Coarse extraction pipeline; 31. Cold trap three; 32. Cold trap sheath; 33. Heating resistance wire; 34. Micro-cooling finger; 35. Check valve. Detailed Implementation

[0031] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0032] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0033] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0034] The Δ47 and Δ48 isotope compositions of carbonate biclusters exhibit a unique equilibrium relationship with carbonate formation temperature. This relationship can be used to identify and study kinetic effects in carbonate minerals. If carbonates form under equilibrium fractionation conditions, the Δ47 and Δ48 isotope compositions of carbonate biclusters will fall on an equilibrium curve with temperature. Carbonates formed under kinetic fractionation conditions will deviate from this equilibrium curve, allowing for the identification of kinetic isotope effects. By removing the influence of kinetic effects, the correct carbonate formation temperature can be derived, resulting in accurate paleotemperature reconstructions. Kinetic effects exist in many geological samples, such as cave carbonates like stalagmites and stalactites, brachiopod shells, corals, and mollusc shells like sea urchins and squid. Previously, measuring only the Δ47 isotope composition of these samples often yielded temperatures higher or lower than their formation environment. Simultaneously measuring their Δ47 and Δ48 isotope compositions overcomes this problem.

[0035] The natural abundance of cluster isotope 47 is approximately 44 ppm, while the natural abundance of cluster isotope 48 is an order of magnitude lower, at only about 4 ppm. Accurate simultaneous measurement of the composition of two cluster isotopes is therefore very challenging. The gas stable isotope mass spectrometer used for testing required some improvements, such as the addition of a 47.5 Faraday half-cup detector and a Faraday cup amplifier for measuring ion beams with mass numbers 47-48-49, which was upgraded to 10. 12 Ω upgraded to 10 13 Ω improves the sensitivity and accuracy of the testing instrument.

[0036] However, the preparation and pretreatment of carbonate samples are crucial for obtaining accurate bicluster isotopic compositions. Existing technologies primarily employ offline manual preparation. Offline sample preparation systems often use glass or stainless steel tubing. The bicluster isotopic compositions of the same sample measured by different laboratories vary significantly, mainly due to differences in offline preparation systems, cumbersome processes (often requiring over two hours to prepare a single sample), and inconsistent preparation methods between laboratories. Manual operation inevitably introduces human error and inconsistencies, resulting in poor reproducibility. All of these factors affect the accuracy of bicluster isotope Δ47 and Δ48 measurements. Furthermore, manual offline sample preparation systems can only prepare 4-5 samples per day, consuming significant manpower and exhibiting low efficiency, making it difficult to meet the high-volume sample analysis needs of laboratories. Therefore, this application provides a fully automated carbonate bicluster isotope sample preparation device, method, and detection system, which can save manpower, reduce human error and inconsistencies, increase sample yield, reduce laboratory waiting time, and meet the testing needs of those skilled in the art.

[0037] This application discloses a fully automated apparatus for preparing carbonate dual-cluster isotope samples. For example... Figure 1 As shown, the sample preparation device includes an automatic sample acid hydrolysis reactor, a balance gas quartz tube breaking device, a purification unit, and a collection unit; as well as a first low-vacuum pumping unit for purifying the automatic sample acid hydrolysis reactor or the balance gas quartz tube breaking device, and a second low-vacuum pumping unit and a high-vacuum pumping unit for purifying the purification unit or the collection unit. The automatic sample acid hydrolysis reactor can pre-store two or more samples and sequentially perform acid hydrolysis reactions on the samples.

[0038] The automatic sample acid hydrolysis reactor and the purification unit are connected through the fourth valve 4. The first valve 1 and the second valve 2 are connected in parallel between the outlet end of the automatic sample acid hydrolysis reactor and the inlet end of the fourth valve 4. The first low vacuum pumping unit is connected to the automatic sample acid hydrolysis reactor through the second valve 2. The balance gas quartz tube breaking device is connected to the first low vacuum pumping unit through the first valve 1.

[0039] The purification unit and the collection unit are connected in series via the thirteenth valve 13 and the sixteenth valve 16. The fourteenth valve 14 and the fifteenth valve 15 are connected in parallel between the thirteenth valve 13 and the sixteenth valve 16. The second low vacuum pumping unit is connected to the collection unit via the fourteenth valve 14, and the high vacuum pumping unit is connected to the collection unit via the fifteenth valve 15.

[0040] The purification unit includes a cold trap 22, an eighth valve 8, a sulfur trap 23, a Porapak trap 24, an eleventh valve 11, and a second cold trap 25 connected in series from the fourth valve 4 to the thirteenth valve 13. A sixth valve 6 and a seventh valve 7 are connected in parallel between the cold trap 22 and the eighth valve 8. The second low vacuum pumping unit is connected to the purification unit through the sixth valve 6, and the high vacuum pumping unit is connected to the purification unit through the seventh valve 7.

[0041] A first helium inlet 26, controlled by a fifth valve 5, is introduced between the fourth valve 4 and the first cold trap 22; a first helium outlet 27, controlled by a twelfth valve 12, is introduced between the second cold trap 25 and the thirteenth valve 13; a second helium inlet 28, controlled by a tenth valve 10, is introduced between the Porapak trap 24 and the eleventh valve 11; and a second helium outlet 29, controlled by a ninth valve 9, is introduced between the eighth valve 8 and the sulfur trap 23.

[0042] Valves 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16 are all automatically controlled valves, with pneumatic valves being the preferred choice.

[0043] In addition, the collection unit can be connected to a stable isotope mass spectrometer.

[0044] In this invention, before each sample reaction, the fourth valve 4 and the first valve 1 are automatically closed, and the second valve 2 is opened. The automatic sample acidification reactor is purified by the first low-vacuum pumping unit to remove the gas remaining after the sample was loaded into the automatic sample acidification reactor or after the previous sample reaction. At the same time, the temperature of the cold trap 22 is lowered to -185°C. Then, the first valve 1 and the second valve 2 are automatically closed, and the fourth valve 4 is opened. At the same time, an acidification reaction is carried out on a certain sample. The sample gas generated by the acidification reaction is frozen by the cold trap 22.

[0045] Then, the temperature of Porapak trap 24 is automatically set to -35℃, and the temperature of cold trap 25 is reduced to -185℃. After the acid hydrolysis reaction is completed, the temperature of cold trap 12 is automatically raised to -90℃, the fourth valve 4 is automatically closed, the eighth valve 8 and the eleventh valve 11 are opened, and the fifth valve 5 is opened at the same time. Helium gas is automatically introduced through the first helium inlet 26 to accelerate gas transfer and purification. Helium gas flows out through the first helium outlet 27, and CO2 gas is collected in cold trap 25. This process can remove trace amounts of water, sulfides, organic matter and other impurities from the gas produced by the acid hydrolysis reaction of the sample or the equilibrium gas sealed in the quartz tube, and purify the CO2 gas.

[0046] After the sample gas is frozen in cold trap 25, valves 5 and 12 are automatically closed to cut off the helium supply line. Then valve 6 is opened, and the remaining helium in the line is first roughly evacuated using the second low-vacuum pumping unit. Then valve 6 is closed, valve 7 is opened, and the system switches to the high-vacuum pumping unit to remove the remaining helium.

[0047] After removing helium from the pipeline, valve 11 is closed, automatically cooling the collection unit to -185°C and raising the temperature of cold trap 25 to -90°C. The sample gas frozen in cold trap 25 thaws, and valves 13 and 16 are opened, allowing the sample gas to automatically freeze into the collection unit. Simultaneously, valves 10 and 9 are automatically opened, automatically raising the temperature of Porapak trap 24 to 170°C. Helium is then automatically introduced in reverse through the second helium inlet 28 to assist in heating and cleaning Porapak trap 24 and sulfur trap 23. Helium flows out through the second helium outlet 29.

[0048] After the CO2 gas freezes in the collection unit, the sixteenth valve 16 is automatically closed, the collection unit is heated, and the temperature is automatically set to -50℃. The CO2 gas thaws from the collection unit and is directly introduced into the stable isotope mass spectrometer for automatic measurement of the dual-cluster isotope composition Δ47 and Δ48.

[0049] After the CO2 gas is transferred from the collection unit, the pipeline is automatically cleaned. The temperature of cold trap 1 22, cold trap 25 and the collection unit automatically rises to 100°C, and the temperature of Porapak trap 24 rises to 120°C. The pipeline is first cleaned by the second low vacuum pumping unit, and then switched to the high vacuum pumping unit to pump a high vacuum.

[0050] After the pipeline is cleaned, the automated sample acidification reactor automatically initiates the acidification reaction of the next carbonate sample, thus starting a new sample reaction, purification, and collection. Similarly, for balance gas detection, a pre-sealed balance gas quartz tube 21 can be pre-installed into the balance gas quartz tube breaking device. Simply open and close the corresponding valves automatically, and the balance gas quartz tube 21 will be broken through the seal by the balance gas quartz tube breaking device.

[0051] This invention allows for the sequential acidification of multiple pre-stored samples without opening the automatic sample acidification reactor, enabling uninterrupted operation even at night. This saves manpower, improves sample reproducibility, and doubles sample output efficiency, increasing the processing capacity from 4-5 samples per day with a manual system to 9-10 samples per day with a fully automated system. This significantly accelerates the processing speed of carbonate dual-cluster isotope samples and alleviates testing queues.

[0052] In some embodiments of the present invention, such as Figure 1 As shown, the first low-vacuum pumping unit includes a third valve 3 connected in series with the second valve 2 and a first mechanical pump P1.

[0053] In some embodiments of the present invention, such as Figure 1 As shown, the outlet end of the second valve 2 is connected to the inlet end of the first mechanical pump P1 through a coarse extraction pipeline 30. The inner diameter of the coarse extraction pipeline 30 is smaller than the inner diameter of the main pipeline connecting the second valve 2, the third valve 3, and the first mechanical pump P1 in series.

[0054] In this embodiment, the roughing line 30 is used for vacuum roughing in the automatic sample acidification reactor to prevent carbonate sample powder from being sucked into the vacuum line due to excessive mechanical pump force.

[0055] In some embodiments of the present invention, such as Figure 1 As shown, the roughing-out line 30 is a 1 / 4-inch stainless steel line.

[0056] Furthermore, the roughing pipeline 30 can be made using a multi-section bending process.

[0057] In some embodiments of the present invention, such as Figure 1 As shown, the first Pirani gauge G1 is introduced into the inlet of the first mechanical pump P1, and the opening of the third valve 3 is controlled according to the detection result of the first Pirani gauge G1.

[0058] In this embodiment, the first Pirani gauge G1 can be used to monitor the vacuum level of the interface pipeline of the automated sample acidolysis reactor or the balance gas quartz tube breaking device.

[0059] In some embodiments of the present invention, software can be used to automatically control the vacuum of the automatic sample acidolysis reactor or the equilibrium gas quartz tube breaking device by using a first mechanical pump P1.

[0060] In some embodiments of the present invention, such as Figure 1 As shown, the high vacuum pumping unit includes a high vacuum pump P4, a seventh valve 7 and a fifteenth valve 15 connected in parallel to the inlet of the high vacuum pump P4, and a cold trap 31 connected in series at the outlet of the seventh valve 7.

[0061] In this embodiment, the cold trap 31 can be used to better remove water from the high vacuum line, increase the vacuum level of the high vacuum line, and prevent oil backflow from the vacuum pump.

[0062] In some embodiments of the present invention, such as Figure 1 As shown, a Penning gauge G4 is introduced into the inlet of the high vacuum pump P4.

[0063] In this embodiment, the Penning gauge G4 can be used to monitor the high vacuum level of high vacuum pipelines.

[0064] In some embodiments of the present invention, the high vacuum unit further includes a Dewar flask liquid nitrogen refrigeration device, which is used for cooling the cold trap 31.

[0065] During sample processing, cold trap 31 is immersed in a Dewar flask liquid nitrogen refrigeration device to remove trace amounts of water from the high vacuum pipeline and to prevent oil backflow from the vacuum pump.

[0066] In some embodiments of the present invention, such as Figure 1 As shown, the second low-vacuum pumping unit includes a second mechanical pump P2, a sixth valve 6, and a fourteenth valve 14 connected in parallel to the inlet of the second mechanical pump P2.

[0067] In some embodiments of the present invention, such as Figure 1 As shown, the low vacuum line L1 of the second low vacuum pumping unit and the high vacuum line L2 of the high vacuum pumping unit both use stainless steel pipes with a diameter of 30mm.

[0068] In some embodiments of the present invention, the vacuum of the purification unit or collection unit can be automatically controlled by software using the second mechanical pump P2 and the high vacuum pump P4.

[0069] In some embodiments of the present invention, such as Figure 1 As shown, the outlet end of the fourth valve 4 is connected to the second Pirani gauge G2; the outlet end of the thirteenth valve 13 is connected to the third Pirani gauge G3.

[0070] In this embodiment, the second Pirani gauge G2 and the third Pirani gauge G3 are used to record and measure the pipeline vacuum of the purification unit in real time. They can monitor whether the sample gas or the equilibrium gas in the equilibrium gas quartz tube 21 generated by the automatic sample acidification reactor is completely frozen into the cold trap 22, or whether the purified CO2 gas is completely frozen into the collection unit.

[0071] In some embodiments of the present invention, such as Figure 1 As shown, particulate filters are connected to the outlet of the automatic sample acidification reactor, the outlet of the balance gas quartz tube breaking device, the inlet of the sulfur trap 23, the inlet and outlet of the Porapak trap 24, the outlet of the fifth valve 5, and the outlet of the tenth valve 10.

[0072] In one embodiment of the present invention, a 60-micron particle filter is provided at the connection point between the outlet end of the automatic sample acidification reactor and the outlet end of the balance gas quartz tube breaking device and the vacuum pipeline. This filter is used to prevent carbonate sample powder or broken glass fragments from entering the vacuum pipeline after the quartz tube is broken, thus preventing blockage of the pneumatic valve.

[0073] In one embodiment of the present invention, the outlet ends of the fifth valve 5 and the tenth valve 10 are respectively connected to particulate filters to prevent dirty particulate matter from entering the vacuum pipeline from the first and second helium inlets 28.

[0074] In one embodiment of the present invention, 60-micron particle filters are connected upstream of sulfur trap 23 and upstream and downstream of Porapak trap 24, respectively, to prevent quartz wool filled in sulfur trap 23 and Porapak trap 24 from entering the vacuum pipeline and clogging the pneumatic valve.

[0075] In some embodiments of the present invention, the sample preparation apparatus further includes a first automatic temperature control system, which is used for cooling or heating the first cold trap 22, the Porapak trap 24, or the second cold trap 25, and the temperature control range of the first automatic temperature control system is -185°C to 200°C.

[0076] In some embodiments of the present invention, such as Figure 2 As shown, the first automatic temperature control system comprises a Dewar flask, a cold trap sleeve 32, and a heating resistance wire 33 wound around the cold trap. It automatically controls the liquid nitrogen level by controlling the pressure inside the cold trap sleeve 32. When freezing CO2 gas at low temperatures is required, the pressure in the cold trap sleeve 32 is reduced, drawing liquid nitrogen from the Dewar flask into the sleeve, raising the liquid nitrogen level, and completely immersing the cold trap in liquid nitrogen for rapid cooling to the target temperature. When high temperatures are required, the pressure in the cold trap sleeve 32 is increased, expelling liquid nitrogen from the sleeve, lowering the liquid nitrogen level, and completely exposing the cold trap. The heating resistance wire wound around the cold trap then heats the cold trap to reach the desired set temperature.

[0077] In some embodiments of the present invention, such as Figure 1 As shown, the collection unit includes a micro-cooling finger 34 and a second automatic temperature control system. The second automatic temperature control system is used to cool or heat the micro-cooling finger 34, so as to freeze carbon dioxide gas, thaw carbon dioxide gas, or heat and clean the micro-cooling finger 34.

[0078] In some embodiments of the present invention, the second automatic temperature control system includes a peristaltic pump capable of evacuating a vacuum and a heating resistance wire. Liquid nitrogen from the Dewar flask can be introduced into the periphery of the micro-cooling finger 34 by evacuating to a low vacuum, rapidly cooling the micro-cooling finger 34 to -185°C to freeze the CO2 gas. A heating resistance wire is wrapped around the micro-cooling finger 34, which can be rapidly heated to thaw the CO2 gas and pass it into a stable isotope mass spectrometer, or heated to clean the micro-cooling finger 34 in preparation for the next sample preparation.

[0079] In some embodiments of the present invention, the micro-cold finger 34 is made of stainless steel with a thin glass liner, replacing the traditional 316 stainless steel pipeline, which can better remove trace amounts of water in the micro-cold trap and facilitate the measurement of Δ48 with a lower content.

[0080] In some embodiments of the present invention, such as Figure 1As shown, the automatic sample acidolysis reactor includes a phosphoric acid bottle 17. The top opening of the phosphoric acid bottle 17 is sealed with a sample turntable 18 through a pipe. The sample turntable 18 is used to pre-store the sample and release the sample into the phosphoric acid bottle 17 through the pipe. A heating jacket 19 is fitted under the lower part of the phosphoric acid bottle 17. A magnetic heating stirrer 20 is provided at the bottom of the phosphoric acid bottle 17. The magnetic heating stirrer 20 and the heating jacket 19 automatically control the temperature inside the phosphoric acid bottle 17 within a range of 20℃ to 400℃. 105% superphosphoric acid can be placed in the phosphoric acid bottle 17.

[0081] In this embodiment, the automatic sample acid hydrolysis reactor can achieve automatic temperature control and automatic sample transfer into the phosphoric acid bottle 17, so as to realize the automatic common acid bath reaction of the samples.

[0082] In some embodiments of the present invention, the sample turntable 18 can hold up to 40 samples and has a motor that can automatically control the samples to fall into the phosphoric acid bottle 17 in sequence. For example, by rotating the turntable, the circumferentially arranged samples are aligned with the pipe and the samples are released into the phosphoric acid bottle 17 in sequence through the pipe.

[0083] In some embodiments of the present invention, the automatic sample acidification reactor can be set to a vacuum level of less than 1×10⁻⁶ by the first mechanical pump P1. -2 mBar, the sample preparation device automatically rotates the motor to push in a small sample cup that falls into the common acid bath bottle.

[0084] In some embodiments of the present invention, the heating sleeve 19 is a polytetrafluoroethylene sleeve with an internal heating mesh, used to heat the side of the phosphoric acid bottle 17.

[0085] In some embodiments of the present invention, the rotor speed of the magnetic heating stirrer 20 can be automatically controlled, with a speed range of 60~1600 rpm, preferably with an acid hydrolysis reaction temperature of 90°C and a rotor speed of 200 rpm.

[0086] In some embodiments of the present invention, ultrapure helium is preferably used as the transfer gas.

[0087] In some embodiments of the present invention, check valves 35 are respectively installed at the outlet ends of the ninth valve 9 and the twelfth valve 12, which are used for both helium flow out and prevention of ambient air from flowing into the pipeline.

[0088] In some embodiments of the present invention, other valves are also preferably automatically controlled pneumatic valves.

[0089] This embodiment also proposes a method for preparing carbonate dual-cluster isotope samples using the above-described carbonate dual-cluster isotope sample preparation apparatus, comprising the following steps:

[0090] First, the automatic sample acidification reactor or the equilibrium gas quartz tube breaking device is purified using the first low-vacuum pumping unit.

[0091] Then, the pre-stored sample is reacted using an automated sample acidification reactor or the equilibrium gas quartz tube is broken. The reaction product or equilibrium gas is purified online in real time by the purification unit and then enters the collection unit. Finally, it is passed into a stable isotope mass spectrometer for dual-cluster isotope measurement.

[0092] Then, the purification unit and the collection unit are vacuumed and cleaned using the second low vacuum unit and the high vacuum unit. The first low vacuum unit is then used again to purify the automatic sample acid hydrolysis reactor or the equilibrium gas quartz tube breaking device, in preparation for the automatic sample acid hydrolysis reactor to react and purify the next sample.

[0093] This embodiment also proposes a carbonate dual-cluster isotope detection system, including the above-mentioned carbonate dual-cluster isotope sample preparation device and a stable isotope mass spectrometer connected to the outlet end of the collection unit.

[0094] In some embodiments of the present invention, the outlet end of the microcooling finger is connected to the sample bellows of the stable isotope mass spectrometer. The carbon dioxide gas thawed by the microcooling finger enters the stable isotope mass spectrometer through the sample bellows, thereby performing automatic measurement of the composition of the dual-cluster isotopes Δ47 and Δ48.

[0095] The preparation method of carbonate bicluster isotope samples will be further explained below with reference to specific embodiments.

[0096] Step 1: Use a volume of approximately 1 cm 3 Multiple carbonate powder samples were weighed into a small quartz sample cup. The carbonate powder samples had a particle size of less than 200 mesh, and each sample weighed 5-10 mg. 10 mL of anhydrous superphosphoric acid (99% purity) was added to a common phosphoric acid flask. Excess P₂O₅ was added to prepare a solution with a density greater than 1.94 g / cm³. 3 For superphosphoric acid with a concentration greater than 105%, place two PTFE stir bar at the bottom of the phosphoric acid flask, cover the flask with a heating mantle, and place it in a suitable environment. Figure 1 On the far left, on the magnetic heating stirrer. Place the small quartz sample cup on... Figure 1The sample turntable can hold up to 40 samples at a time. The sealed equilibrium gas quartz tube is then attached to the equilibrium gas quartz tube breaking device. The software automatically controls the first mechanical pump to evacuate the automatic sample acidolysis reactor or the equilibrium gas quartz tube breaking device. Connect the Ultra-torr stainless steel vacuum connector, set the phosphoric acid heating temperature to 90℃, and the rotor speed to 200 rpm. The software automatically opens the second valve, bypassing the roughing line via the third valve. First, the first mechanical pump (low vacuum pump) roughly evacuates the sample reaction flask until the G1 Pirani gauge vacuum is below 1×10⁻⁶. -1 mBar, then the third valve automatically opens to evacuate the vacuum, preventing sample powder from being drawn into the vacuum line due to a sudden increase in pump flow rate, thus avoiding contamination of the pipeline and blockage of the pneumatic valve. The phosphoric acid bottle is evacuated and degassed for 1 hour, until the vacuum level of the first Pirani gauge G1 is below 3 × 10⁻⁶. -3 mBar.

[0097] Step 2, Cold trap as follows Figure 2 The software automatically controls the process, reducing the pressure in the cold trap jacket, causing the liquid nitrogen level to rise and immerse the first cold trap, lowering the temperature to -185℃. The second and third valves automatically close, while the fourth valve opens. Simultaneously, the sample turntable motor automatically rotates, pushing in a small quartz cup, and a sample falls into the phosphoric acid bottle. The acidolysis reaction produces sample gas, which is frozen in the first cold trap. The reaction time is 10 minutes, and the completeness of the acidolysis reaction can be monitored using the second Pirani gauge G2.

[0098] Step 3: The temperature of the Porapak trap is automatically set to -35℃, the temperature of cold trap two is lowered to -185℃, and cold trap three is automatically and continuously submerged in liquid nitrogen during the sample reaction and processing, with its temperature set to -185℃. After the acid hydrolysis reaction is completed, the temperature of cold trap one is automatically raised to -90℃, the fourth valve is automatically closed, and the eighth and eleventh valves are opened. Simultaneously, the fifth valve is opened, and He gas is introduced through the first helium inlet. The He gas passes through cold trap one, and the thawed sample gas is sequentially passed through the sulfur trap, the Porapak trap, and frozen in cold trap two. The He gas flows out from the first helium outlet. The sample gas is purified to obtain pure CO2 gas after removing water, sulfides, and organic compounds. The He gas flow rate is set to 35 mL / min, and the sample purification and transfer time is 30 minutes.

[0099] Step 4: After the sample gas is frozen in cold trap 2, automatically close valves 5 and 12 to cut off the He gas supply line, open valve 6, first use the second mechanical pump (low vacuum pump) to roughly evacuate the remaining He gas in the line, then close valve 6, open valve 7, and switch to high vacuum pump to evacuate the remaining He gas.

[0100] Step 5: Close valve 11, automatically cooling the micro-cooling finger to -185℃ and raising the temperature of cold trap 2 to -90℃. The sample gas frozen in cold trap 2 will thaw. Open valves 13 and 16, and the sample gas will automatically freeze into the micro-cooling finger over 7 minutes. Simultaneously, valves 10 and 9 will automatically open, automatically raising the temperature of the Porapak trap to 170℃. He gas will be automatically introduced in reverse through the second helium inlet to assist in heating and cleaning the Porapak trap and sulfur trap. He gas will flow out through the second helium outlet. The He gas heating and cleaning process will take 30 minutes.

[0101] Step 6: After the CO2 gas is frozen in the micro-cooling finger, the sixteenth valve is automatically closed, the micro-cooling finger is heated, and the temperature is automatically set to -50℃. The CO2 gas is thawed from the micro-cooling finger and directly introduced into the sample bellows of the stable isotope mass spectrometer for automatic measurement of the dual-cluster isotopes Δ47 and Δ48.

[0102] Step 7: After the CO2 gas transfer is complete, the pipeline is automatically cleaned. The temperatures of Cold Trap 1, Cold Trap 2, and the micro-cooling finger automatically rise to 100°C, and the Porapak trap temperature rises to 120°C. First, the pipeline is cleaned using the second mechanical pump, then switched to a high-vacuum pump to evacuate to a high vacuum. The pipeline cleaning time is 30 minutes. At the same time, the Dewar flask is automatically replenished with liquid nitrogen from the external liquid nitrogen tank to prepare for cooling Cold Trap 1, the Porapak trap, and Cold Trap 2 when processing the next sample.

[0103] After the pipeline is cleaned, the sample turntable rotates automatically, and the next carbonate sample falls into the common acid bath bottle, starting a new sample reaction, purification, and collection. This allows for automated sequential reactions without opening the automatic sample acidification reactor, processing up to 40 samples simultaneously, even overnight. This saves manpower, improves sample reproducibility, and doubles sample output efficiency, increasing it from 4-5 samples per day with a manual system to 9-10 samples per day with a fully automated system. This significantly accelerates the processing speed of carbonate dual-cluster isotope samples and alleviates testing queues.

[0104] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A device for preparing carbonate dual-cluster isotope samples, characterized in that, include: Automated sample acidification reactor, equilibrium gas quartz tube breaking device, purification unit and collection unit; and The first low-vacuum pumping unit is used to purify the automatic sample acid hydrolysis reactor or the balance gas quartz tube breaking device; the second low-vacuum pumping unit and the high-vacuum pumping unit are used to purify the purification unit or the collection unit; the automatic sample acid hydrolysis reactor can pre-store two or more samples and perform acid hydrolysis reactions on the samples in sequence; and the collection unit includes a micro-cooling finger, which is made of stainless steel with a thin glass liner. The automated sample acidification reactor is connected to the purification unit via a fourth valve. A first valve and a second valve are connected in parallel between the outlet of the automated sample acidification reactor and the inlet of the fourth valve. The first low-vacuum pumping unit is connected to the automated sample acidification reactor via the second valve. The balance gas quartz tube breaking device is connected to the first low-vacuum pumping unit via the first valve. The first low-vacuum pumping unit includes a third valve and a first mechanical pump connected in series with the second valve. The outlet of the second valve and the inlet of the first mechanical pump are connected via a coarse-pumping pipeline. The inner diameter of the coarse-pumping pipeline is smaller than the inner diameter of the main pipeline connecting the second valve, the third valve, and the first mechanical pump in series. The purification unit and the collection unit are connected in series via a thirteenth valve and a sixteenth valve. A fourteenth valve and a fifteenth valve are connected in parallel between the thirteenth valve and the sixteenth valve. The second low-vacuum pumping unit is connected to the collection unit via the fourteenth valve, and the high-vacuum pumping unit is connected to the collection unit via the fifteenth valve. The purification unit includes a cold trap one, an eighth valve, a sulfur trap, a Porapak trap, an eleventh valve, and a cold trap two connected in series from the fourth valve to the thirteenth valve. A sixth valve and a seventh valve are connected in parallel between the cold trap one and the eighth valve. The second low vacuum pumping unit is connected to the purification unit through the sixth valve, and the high vacuum pumping unit is connected to the purification unit through the seventh valve. A first helium inlet, controlled by a fifth valve, is introduced between the fourth valve and the first cold trap; a first helium outlet, controlled by a twelfth valve, is introduced between the second cold trap and the thirteenth valve; a second helium inlet, controlled by a tenth valve, is introduced between the Porapak trap and the eleventh valve; and a second helium outlet, controlled by a ninth valve, is introduced between the eighth valve and the sulfur trap. All of the valves mentioned are automatically controlled valves.

2. The carbonate dual-cluster isotope sample preparation apparatus according to claim 1, characterized in that, A first Pirani gauge is introduced into the inlet of the first mechanical pump, and the opening of the third valve is controlled based on the detection result of the first Pirani gauge.

3. The carbonate dual-cluster isotope sample preparation apparatus according to claim 1, characterized in that, The high vacuum pumping unit includes a high vacuum pump. The seventh valve and the fifteenth valve are connected in parallel to the inlet of the high vacuum pump. A cold trap is connected in series at the outlet of the seventh valve. A Penning gauge is introduced at the inlet of the high vacuum pump.

4. The carbonate dual-cluster isotope sample preparation apparatus according to claim 1, characterized in that, The outlet end of the fourth valve is connected to a second Pirani gauge; the outlet end of the thirteenth valve is connected to a third Pirani gauge.

5. The carbonate dual-cluster isotope sample preparation apparatus according to claim 1, characterized in that, The outlet end of the automatic sample acidification reactor, the outlet end of the balance gas quartz tube breaking device, the inlet end of the sulfur trap, the inlet and outlet ends of the Porapak trap, the outlet end of the fifth valve, and the outlet end of the tenth valve are respectively connected to particulate filters.

6. The carbonate dual-cluster isotope sample preparation apparatus according to claim 1, characterized in that, It also includes a first automatic temperature control system, which is used for cooling or heating the first cold trap, the Porapak trap, or the second cold trap, and the temperature control range of the first automatic temperature control system is -185℃ to 200℃.

7. The carbonate dual-cluster isotope sample preparation apparatus according to claim 1, characterized in that, The collection unit also includes a second automatic temperature control system, which is used for cooling or heating the micro-cold finger to freeze carbon dioxide gas, thaw carbon dioxide gas, or heat and clean the micro-cold finger.

8. The carbonate dual-cluster isotope sample preparation apparatus according to claim 1, characterized in that, The automatic sample acidolysis reactor includes a phosphoric acid bottle. The top opening of the phosphoric acid bottle is sealed with a sample turntable through a pipe. The sample turntable is used to pre-store the sample and release the sample into the phosphoric acid bottle through the pipe. A heating jacket is fitted around the bottom of the phosphoric acid bottle. A magnetic heating stirrer is provided at the bottom of the phosphoric acid bottle. The magnetic heating stirrer and the heating jacket automatically control the temperature inside the phosphoric acid bottle within a range of 20℃ to 400℃.

9. A method for preparing carbonate dual-cluster isotope samples using the carbonate dual-cluster isotope sample preparation apparatus as described in any one of claims 1 to 8, characterized in that, Includes the following steps: First, the automatic sample acid hydrolysis reactor or the equilibrium gas quartz tube breaking device is purified using the first low vacuum pumping unit. Then, the pre-stored sample is reacted using an automated sample acidification reactor or the equilibrium gas quartz tube is broken. The reaction product or equilibrium gas is purified online in real time by the purification unit and then enters the collection unit. It is then passed into a stable isotope mass spectrometer for dual-cluster isotope measurement. Then, the purification unit and the collection unit are vacuumed and cleaned using the second low vacuum unit and the high vacuum unit. The first low vacuum unit is then used again to purify the automatic sample acid hydrolysis reactor or the equilibrium gas quartz tube breaking device, in preparation for the automatic sample acid hydrolysis reactor to react and purify the next sample.

10. A carbonate dual-cluster isotope detection system, characterized in that, It includes the carbonate dual-cluster isotope sample preparation apparatus as described in any one of claims 1 to 8, and a stable isotope mass spectrometer connected to the outlet end of the collection unit.

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