High-precision measurement method for Ge content of geological sample

Abstract

The invention provides a geological sample Ge content high-precision determination method, which comprises: collecting and crushing a geological sample, weighing the crushed geological sample, and dissolving the sample; the method comprises the following steps: primarily measuring the Ge content by adopting an external standard method in combination with ICP-MS (Inductively Coupled Plasma Mass Spectrometry) to obtain primary Ge content data, and determining the addition amount of a Ge diluent according to the primary Ge content data; the method comprises the following steps: accurately weighing a geological sample and a Ge diluent, and sequentially adding the weighed geological sample and Ge diluent into a sample dissolving container for sample dissolving to obtain a dissolving solution; carrying out Ge separation and purification on the dissolved solution by adopting an anion exchange method to obtain a solution containing a Ge element; and carrying out high-precision determination on the solution containing the Ge element by adopting MC-ICP-MS to obtain the content of Ge. According to the method, the Ge content in the ppb-level geological sample can be accurately measured, and the precision of Ge content measurement is improved.

Description

Technical Field

[0001] This invention belongs to the field of Ge content determination technology, specifically relating to a high-precision method for determining the Ge content in geological samples. Background Technology

[0002] Research on Ge has long been hampered by the analytical challenges posed by low Ge concentrations in crustal rocks. Early attempts to analyze Ge content composition using electron impact ionization mass spectrometry (EIS), thermal ionization mass spectrometry (TIMS), solid-state source mass spectrometry (SMS), secondary ionization mass spectrometry (SIMS), and gas isotope mass spectrometry (GIMS) have proven problematic. First, current methods for testing Ge content mainly use inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), and atomic fluorescence spectrometry (AFS), but these methods have low sensitivity, poor detection limits, and low accuracy. Second, conventional analytical methods often involve dissolving the sample in aqua regia and simultaneously analyzing multiple trace elements. However, GeCl4, generated from the reaction of Ge with HCl, is highly volatile, leading to lower-than-expected results in subsequent analyses. Furthermore, Ge's chemical properties are similar to Si, and it easily substitutes for Si in quartz in a homologous form, making it impossible for conventional aqua regia systems to release Ge from quartz. Third, Ge has many interfering ions, and its chemical separation and enrichment processes are primarily used in isotope composition studies. The content analysis process lacks a targeted separation and enrichment process, failing to establish a high-precision method for Ge content analysis.

[0003] To address the aforementioned issues, it is necessary to propose a well-designed and effective method for high-precision determination of Ge content in geological samples. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art, and to provide a high-precision method for determining the Ge content of geological samples.

[0005] This invention provides a high-precision method for determining the Ge content in geological samples, the method comprising: Step 1: Collect and crush geological samples, and weigh the crushed geological samples for dissolution. Step 2: Use the external standard method combined with ICP-MS to perform preliminary determination of Ge content, obtain preliminary Ge content data, and determine the amount of Ge diluent to be added based on the preliminary Ge content data; Step 3: Accurately weigh the geological sample and Ge diluent, and then add the weighed geological sample and Ge diluent to the dissolving container in sequence to dissolve the sample and obtain the dissolving solution; Step 4: Use anion exchange to separate and purify Ge in the solution to obtain a solution containing Ge. Step 5: The Ge-containing solution is analyzed with high precision using MC-ICP-MS to obtain the Ge content.

[0006] Optionally, step four involves using anion exchange to separate and purify Ge from the solution, including: An anion exchange resin column is provided, and the anion exchange resin column is cleaned and equilibrated. The solution was loaded into the anion exchange resin column, and 2 mL of 1M HF was added to the anion exchange resin column in 5 to 6 portions for elution to remove impurities. Add 2 mL to 3 mL of Q water to the anion exchange resin to further wash away impurities; The anion exchange resin column was eluted with 2 mL of 3M HNO3 in 5 to 6 separate additions to obtain a solution containing Ge.

[0007] Optionally, the volume of the anion exchange resin column is 1 mL to 2 mL.

[0008] Optionally, the anion exchange resin column is an AG-1-8X anion exchange resin column.

[0009] Optionally, the anion exchange resin column is cleaned and equilibrated, including: First, add 2 mL of 3 M HNO3 to the anion exchange resin column in 5 to 6 portions to clean the resin; Add 2 mL of Q water to the anion exchange resin column 5 to 6 times to wash the resin. Finally, 1 mL of 1 M HF was added to the anion exchange resin column 5 to 6 times to wash and equilibrate the resin.

[0010] Optionally, in step one, the crushed geological sample is weighed and dissolved, including: Accurately weigh 0.02 g to 0.5 g of sample into a 10 mL Teflon-sealed container; Add 1 mL HF, 1 mL HClO3 and 3 mL HNO3 to a Teflon-sealed container; After fitting the Teflon can with a metal sleeve, place it in an oven and heat at 200℃~250℃ for 10 h~12 h.

[0011] Optionally, after weighing and dissolving the crushed geological sample, the method further includes: After the solution has cooled, transfer the solution from the Teflon container to a plastic centrifuge tube; After making up to volume with ultrapure water, centrifuge the solution and collect the supernatant in a PFA dissolution vessel. Place the PFA dissolution vessel on a hot plate and heat it to dryness. Then add HNO3 to redissolve it. Repeat this process twice. Finally, dilute the solution to 2 mL to 5 mL of 2% to 5% HNO3 solution for instrument testing.

[0012] Optionally, step three includes: Accurately weigh 0.02 g to 0.5 g of geological sample into a Teflon-sealed container; Use a pipette to add the weighed Ge diluent to the PFA dissolving vessel, and then use 1 mL of concentrated HNO3 to transfer the Ge diluent from the PFA dissolving vessel to a Teflon-sealed container to mix with the sample. Repeat the transfer three times, then add 1 mL of HF and 1 mL of HClO3 to the Teflon-sealed container; After fitting a metal sleeve over a Teflon canister, place it in an oven and heat at 200℃~250℃ for 10h~12h to obtain the solution.

[0013] Optionally, after obtaining the solution, the method further includes: After the solution has cooled, transfer the solution from the Teflon container to a plastic centrifuge tube; After making up to volume with pure water, centrifuge the solution and collect the supernatant in a PFA dissolution vessel. The PFA dissolution vessel was heated to dryness on a hot plate, then HF was added to redissolve it. This process was repeated twice. Finally, the solution was diluted to 2-3 mL of 1 M HF solution for column loading.

[0014] Optionally, step five includes: Establish the cup structure for static determination of Ge isotopes; Ge isotope determination was performed using MC-ICP-MS based on the described cup structure; The Ge content is obtained based on the measured Ge isotopes.

[0015] The high-precision method for determining the Ge content in geological samples of the present invention combines a multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS) with an isotope dilution method, which has extremely high sensitivity, resolution and stability, to measure the Ge content. At the same time, a targeted and simplified Ge separation and enrichment process is introduced in the pretreatment process, which can accurately determine the Ge content in geological samples at the ppb level, thereby improving the accuracy of Ge content determination. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating a method for high-precision determination of Ge content in geological samples according to an embodiment of the present invention. Figure 2This is a schematic diagram showing the relationship between isotope ratio and error amplification factor, provided for another embodiment of the present invention. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, the present invention provides a high-precision method S100 for determining the Ge content of geological samples, the method comprising: Step 1: Collect and crush geological samples, and weigh the crushed geological samples for dissolution.

[0019] Specifically, geological samples are collected and crushed to approximately 200 mesh. The specific process for weighing and dissolving the crushed geological samples is as follows: First, accurately weigh 0.02 g to 0.5 g of the sample into a 10 mL Teflon-coated container. Specifically, use a Class I balance (d=0.01 mg / 0.1 mg, max=42 g / 152 g) to accurately weigh 0.02 g to 0.5 g of the sample into a 10 mL Teflon-coated container.

[0020] Secondly, add 1 mL of HF (superior grade), 1 mL of HClO3 (superior grade), and 3 mL of HNO3 (superior grade) to the Teflon-sealed container.

[0021] Next, after fitting the Teflon can with a metal sleeve, place it in an oven and heat at 200℃~250℃ for 10 h~12 h. Specifically, after fitting the Teflon can with a metal sleeve, place it in an oven and heat at 200℃ for 12 h.

[0022] In this embodiment, a system of 1 mL HF (superior purity), 1 mL HClO3 (superior purity) and 3 mL HNO3 (superior purity) is used for sample dissolution. HF can release the Ge element in the quartz, and the addition of HClO3 is more conducive to dissolving the insoluble geological sample without causing Ge to react with and form volatile GeCl4.

[0023] The method further includes, after weighing and dissolving the crushed geological sample, the following steps: First, after the solution has cooled, transfer it from the Teflon container to a plastic centrifuge tube. Specifically, after the solution has cooled, transfer it from the Teflon container to a 15 mL plastic centrifuge tube.

[0024] Next, after bringing the volume down with ultrapure water, centrifuge the sample and collect the supernatant in a PFA dissolving vessel. Specifically, bring the volume down to 10 mL with ultrapure water and centrifuge at 2000 rpm for 10 min.

[0025] Then, the PFA dissolution vessel is placed on a hot plate and heated to dryness, then HNO3 is added to redissolve it, and this process is repeated twice. Finally, the solution is diluted to 2 mL ~ 5 mL of 2% ~ 5% HNO3 solution for instrument testing.

[0026] Specifically, take 0.5 mL of supernatant into a 15 mL PFA dissolution vessel, place the PFA dissolution vessel on a 150℃ hot plate to heat and evaporate to dryness, then add HNO3 to redissolve, repeat twice, and finally adjust the volume to 2 mL ~ 5 mL 2% ~ 5% (depending on the sample volume, the solution for instrumentation is roughly diluted 1000 ~ 2000 times) for instrumentation testing.

[0027] In this embodiment, the dissolved sample is centrifuged to prevent invisible fine particles from clogging the injector during the instrumentation process. At the same time, nitric acid is added multiple times to redissolve the sample in order to remove HCl and prevent its chloride ions from interfering with and damaging the instrument.

[0028] Step 2: Use the external standard method combined with ICP-MS to perform preliminary Ge content determination, obtain preliminary Ge content data, and determine the amount of Ge diluent to be added based on the preliminary Ge content data.

[0029] Specifically, ICP-MS was used to directly test the solution after volume adjustment to quickly obtain the preliminary Ge isotope ratio. Then, the initial Ge content data was calculated based on the Ge isotope ratio, and the amount of Ge diluent to be added was determined based on the preliminary Ge content data.

[0030] The Ge content is calculated based on the measured Ge isotope ratios using the following formula: , Table 1. Meaning and values ​​of each variable in Equation 1-1

[0031] Differentiating from equation (1-1) yields: ; Equations 1-2 express the error propagation in calculating the content from the isotope ratio. It can be seen from the above equation that the magnitude of the isotope ratio R after mixing directly affects the error amplification of the dilution method. Let the amplification factor be: ; Based on the above formula, the amplification factor Fmag is relative to the isotope ratio R. Figure 2 As shown, Figure 2 The relationship between the magnification factor and the isotopic ratio after mixing the sample and diluent is visually illustrated. For Ge... 73 Ge / 70The change in the Ge ratio corresponds to a ratio with the smallest amplification factor. To obtain the isotope ratio at the optimal dilution, let the first derivative of equation 1-3... This allows us to determine the A / B isotope ratio R at the minimum amplification factor, i.e., the optimal dilution. opt : ; The calculation based on the above formula yields the result when measuring Ge. 73 Ge / 70 The optimal dilution ratio for Ge is 0.03, which minimizes error amplification. However, considering that the optimal measurement ratio for ICP-MS should be 1.0, a compromise is adopted in practical analysis, with a dilution ratio of 0.6 chosen for the isotopic ratio of Ge. Therefore, the ideal mass ratio of diluent to sample (i.e., amount of diluent added / amount of analyte in the sample) for Ge is 0.2, as shown in the last row of Table 1-1. The amount of diluent added should ideally be close to this mass ratio; too high or too low a ratio will result in excessive errors in the measurement of element content and isotopic ratios.

[0032] In this embodiment, the external standard method combined with ICP-MS is used to perform preliminary Ge content determination to obtain preliminary Ge content data. Based on the preliminary Ge content data, the amount of Ge diluent to be added is determined, which can yield more accurate content results.

[0033] Step 3: Accurately weigh the geological sample and Ge diluent, and then add the weighed geological sample and Ge diluent to the dissolving container in sequence to dissolve the sample and obtain the dissolving solution.

[0034] The specific process of step three can be as follows: First, accurately weigh 0.02 g to 0.5 g of geological sample into a Teflon-sealed container. Specifically, use a Class I balance (d=0.01mg / 0.1mg, max=42g / 152g) to accurately weigh 0.02 g to 0.5 g of sample into a 10 mL Teflon-sealed container.

[0035] Next, use a pipette to add the weighed Ge diluent to the PFA dissolving vessel, and then use 1 mL of concentrated HNO3 to transfer the Ge diluent from the PFA dissolving vessel to a Teflon-sealed container to mix with the sample.

[0036] Specifically, use a pipette to transfer and accurately weigh an appropriate amount using a balance. 73 Place the Ge diluent into the corresponding 15 mL PFA dissolution vessel, and then use 1 mL of concentrated HNO3 (analytical grade) to transfer the diluent from the PFA dissolution vessel into the corresponding Teflon-sealed container to mix with the sample.

[0037] Next, after repeating the transfer three times, add 1 mL of HF and 1 mL of HClO3 to the Teflon-sealed container. Specifically, after repeating the transfer three times (adding 3 mL of HNO3 to the container), add 1 mL of HF (analytical grade) and 1 mL of HClO3 (analytical grade) to the Teflon-sealed container. The HNO3-HF-HClO3 system allows for better sample dissolution.

[0038] Finally, the Teflon can is fitted with a metal sleeve and placed in an oven at 200℃~250℃ for 10h~12h to obtain the solution. Specifically, the Teflon can is fitted with a metal sleeve and placed in an oven at 200℃ for 12h to dissolve the sample.

[0039] In this embodiment, directly adding the diluent to the sealed container containing the sample would cause the nitric acid medium in the diluent to react directly with the sample, potentially even generating bubbles. During this process, it is impossible to accurately weigh the diluent. Therefore, the diluent must be weighed in advance into its corresponding container and then transferred to the sealed container with HNO3 to mix with the sample, thus improving the accuracy of the diluent weighing. Furthermore, adding the diluent before dissolving the sample and heating it for an extended period helps ensure uniform mixing of the sample and diluent, achieving isotopic equilibrium. Even if some sample is lost during the dissolution process or subsequent experiments, it will not affect the analytical results, improving the measurement structure.

[0040] The method further includes, after obtaining the solution, the following steps: First, after the solution has cooled, transfer the solution from the Teflon container to a plastic centrifuge tube. Specifically, after the solution has cooled, transfer the solution and insoluble matter from the Teflon container to a 15 mL plastic centrifuge tube.

[0041] Next, after bringing the volume down with pure water, centrifuge the sample and collect the supernatant in a PFA dissolving vessel. Specifically, bring the volume down to 5 mL with ultrapure water, centrifuge at 2000 rpm for 10 min, and collect all the supernatant in a 15 mL PFA dissolving vessel.

[0042] Finally, the PFA dissolution vessel was placed on a hot plate and heated to dryness, then HF was added to redissolve it. This process was repeated twice. Finally, the solution was diluted to 2 mL to 3 mL of 1 M HF solution for column loading.

[0043] Specifically, the PFA dissolution vessel is placed on a 150°C hot plate and heated to dryness, then HF is added to redissolve it. This process is repeated twice. Finally, the solution is diluted to 3 mL of 1 M HF solution for column loading.

[0044] In this embodiment, adding HF multiple times to reconstitute the solution can convert it into a hydrofluoric acid medium, which is helpful for subsequent column chromatography experiments. Before each reconstitution, the solution should be evaporated as much as possible to ensure that nitric acid and other substances are removed.

[0045] Step 4: Use anion exchange to separate and purify Ge in the solution to obtain a solution containing Ge.

[0046] The specific process of step four can be as follows: 1) Provide an anion exchange resin column, and clean and equilibrate the anion exchange resin column. The volume of the anion exchange resin column is 1 mL to 2 mL. The anion exchange resin column used is an AG-1-8X anion exchange resin column.

[0047] Specifically, in this embodiment, an AG-1-8X (200-400 mesh) anion exchange resin column with a column volume of about 1 mL is prepared.

[0048] The cleaning and column equilibration of the anion exchange resin column include: First, add 2 mL of 3 M HNO3 to the anion exchange resin column in 5 to 6 separate additions to clean the resin.

[0049] Add 2 mL of Q water to the anion exchange resin column 5 to 6 times to wash the resin.

[0050] Finally, 1 mL of 1 M HF was added to the anion exchange resin column 5 to 6 times to wash and equilibrate the resin.

[0051] 2) Load the solution into the anion exchange resin column, and add 2 mL of 1 M HF into the anion exchange resin column in 5 to 6 batches for filtration and extraction to remove impurities.

[0052] 3) Add 2 mL to 3 mL of Q water to the anion exchange resin to further wash away impurities.

[0053] 4) Add 2 mL of 3M HNO3 to the anion exchange resin column 5 to 6 times for filtration and extraction to obtain a solution containing Ge element.

[0054] As shown in Table 2, the process of separating and purifying Ge using an anion exchange resin column in this embodiment is as follows: 1) Prepare an AG-1-8X (200-400 mesh) anion exchange resin column with a column volume of about 1 mL. First, add 2 mL of 3 M HNO3 (total 10 mL) in 5 portions to wash the resin. Then, add 2 mL of Q water (total 10 mL) in 5 portions to wash the resin. Finally, add 1 mL of 1 M HF (total 5 mL) in 5 portions to wash and equilibrate the resin.

[0055] 2) Add the prepared 3 mL 1 M HF solution to the anion exchange resin column to attach Ge element to the resin. Add 2 mL 1 M HF in 5 portions (10 mL in total) to elute impurities. Finally, add 2 mL Q water to elute impurities.

[0056] 3) Collect Ge element by adding 2 mL of 3 M HNO3 in 6 portions (12 mL in total). Transfer the collected solution to a 15 mL PFA dissolution vessel, evaporate to dryness twice on a 150℃ hot plate, and then dissolve in 3 mL of 2~5% HNO3 solution for instrument testing.

[0057] In this embodiment, adding the eluent in small amounts multiple times maximizes the adsorption / complexation efficiency between the target element and the resin, reduces matrix interference and target element loss, and improves the separation effect of Ge element. Furthermore, in this embodiment, only one resin column is needed to separate and enrich Ge element, reducing costs; in addition, the volume of both resin and eluent is small, eliminating the need for a large amount of solvent to separate Ge element, further reducing costs.

[0058] Table 2. Process of separating and purifying Ge from the solution using anion exchange method.

[0059] Step 5: The Ge-containing solution is analyzed with high precision using MC-ICP-MS to obtain the Ge content.

[0060] Specifically, step five may include: Establish a cup structure for static determination of Ge isotopes; perform MC-ICP-MS determination of Ge isotopes based on the cup structure; and obtain the Ge content based on the measured Ga isotopes.

[0061] Specifically, the Ge content was analyzed directly using a Neptune Plus MC-ICP-MS manufactured by Thermo Fisher Scientific. The multi-receiver inductively coupled plasma mass spectrometer at the Key Laboratory of Re-Os, National Geological Experiment and Testing Center, employed both energy and mass focusing modes. Equipped with dynamic zoom technology, it improved ion mass dispersion by 17%. It featured seven Faraday cup receivers and a fixed central channel ion counter receiver. In addition to the central cup, four electric motors on each side (high and low mass number) were used for precise positional adjustments. An electron multiplier was located behind the central cup, and four ion counters were positioned outside the lowest mass number cup. This system enabled simultaneous static Faraday cup measurement and quasi-static measurement with single-peak jumping of the ion counters. The use of a high-sensitivity JET sampling cone and X-shaped truncation cone significantly improved sensitivity by approximately two times, achieving an internal measurement accuracy of less than 0.05%. For Ge, simultaneous determination was performed using static Faraday mode. 73 Gehe 70 Ge was corrected using a Ge standard solution as an external standard.

[0062] Finally, the Ge content in the sample was calculated using the isotope dilution method. The specific calculation process can be found in Formula 1-1 used for the initial Ge content determination, and will not be repeated here.

[0063] The high-precision method for determining the Ge content in geological samples of the present invention combines a multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS) with isotope dilution method for Ge content measurement, which has extremely high sensitivity, resolution and stability. At the same time, a targeted and simplified Ge separation and enrichment process is introduced in the pretreatment process, which can accurately determine the Ge content in geological samples at the ppb level, thereby improving the accuracy of Ge content determination.

[0064] The high-precision method for determining the Ge content in geological samples of this invention was used to analyze standard substances GBW07270, GBW07128, and GBW07107. The analysis results are as follows: The experimental procedure is blank as follows: Table 3 Experimental Procedure Data

[0065] The detection limit of Ge in this experiment can be calculated from Table 3. The limit is 0.02 ppb, which is three times the standard deviation of six consecutive determinations of the blank in the whole process.

[0066] The detection limit data for Ge content determination using mainstream analytical methods such as ICP-MS are shown in Table 4. As can be seen, the detection limit data for Ge content is worse than that obtained by the method of this invention.

[0067] Table 4. Detection limits of the Ge method in different literature.

[0068] Meanwhile, the analysis of Ge elemental content mainly focused on samples at the ppm level, with very few samples at the ppb level, as shown in Table 5: Table 5. Precision and accuracy of the Ge method in different literature.

[0069] In summary, the detection limit of Ge content in geological samples determined by the high-precision method of the present invention (0.02 ppb) is significantly lower than the detection limit of current mainstream analytical methods (6 ppb ~ 60 ppb), and can handle the analysis and testing of samples at the ppb level.

[0070] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for high-precision determination of the content of Ge in a geological sample, characterized in that, The method comprises: Step one, collecting and crushing geological samples, and weighing the crushed geological samples for dissolution; Step two, preliminary Ge content determination by external standard method combined with ICP-MS to obtain preliminary Ge content data, and determining the amount of Ge diluent added according to the preliminary Ge content data; Step three, accurately weighing the geological samples and the Ge diluent, and sequentially adding the weighed geological samples and the Ge diluent into a dissolution container for dissolution to obtain a dissolution solution; Step four, Ge separation and purification of the dissolution solution by anion exchange method to obtain a Ge element-containing solution; Step five, high-precision determination of the Ge element-containing solution by MC-ICP-MS to obtain the Ge content.

2. The method of claim 1, wherein, In step four, the Ge separation and purification of the dissolution solution by anion exchange method comprises: providing an anion resin column and cleaning and column balancing the anion resin column; loading the dissolution solution into the anion resin column, adding 2 mL of 1M HF to the anion resin column in 5-6 times for leaching and elution to elute impurities; adding 2 mL-3 mL of Q water to the anion resin for further elution of impurities; continuing to add 2 mL of 3M HNO3 to the anion resin column in 5-6 times for leaching and elution to obtain a Ge element-containing solution.

3. The method of claim 2, wherein, The volume of the anion resin column is 1 mL-2 mL.

4. The method of claim 2, wherein, The anion resin column uses an AG-1-8X anion resin column.

5. The method of claim 2, wherein, The cleaning and column balancing of the anion resin column comprises: firstly adding 2 mL of 3M HNO3 to the anion resin column in 5-6 times for cleaning the resin; then adding 2 mL of Q water to the anion resin column in 5-6 times for cleaning the resin; finally adding 1 mL of 1M HF to the anion resin column in 5-6 times for cleaning and balancing the resin.

6. The method according to any one of claims 1 to 5, characterized in that, In step one, the weighing of the crushed geological samples for dissolution comprises: accurately weighing 0.02 g-0.5 g of samples in a 10 mL Teflon bomb; adding 1 mL of HF, 1 mL of HClO3 and 3 mL of HNO3 to the Teflon bomb; after the Teflon bomb is sleeved with a metal sleeve, it is placed in an oven at 200℃-250℃ for heating for 10 h-12 h.

7. The method of claim 6, wherein, After the weighing of the crushed geological samples for dissolution, the method further comprises: after the solution is cooled, the solution in the Teflon bomb is transferred to a plastic centrifuge tube; after constant volume with ultrapure water, centrifugation is performed with a centrifuge, and the supernatant is taken in a PFA dissolution tank; the PFA dissolution tank is placed on an electric heating plate for heating and evaporation, and then HNO3 is added for redissolution, which is repeated twice, finally the solution is constant volume in 2 mL-5 mL of 2%-5% HNO3 solution for machine testing.

8. The method according to any one of claims 1 to 5, characterized in that, In step three, it comprises: accurately weighing 0.02 g-0.5 g of geological samples in a Teflon bomb; adding the weighed Ge diluent into a PFA dissolution tank with a pipette, and then adding 1 mL of concentrated HNO3 to transfer the Ge diluent in the PFA dissolution tank into the Teflon bomb for mixing with the samples; After repeating the transferring for 3 times, 1 mL of HF and 1 mL of HClO3 were added into the Teflon jar; After the Teflon jar was sleeved with a metal sleeve, the jar was heated in an oven at 200-250 DEG C for 10-12 h to obtain the dissolving solution.

9. The method of claim 8, wherein, After the dissolving solution was obtained, the method further comprises: After the dissolving solution was cooled, the dissolving solution in the Teflon jar was transferred into a plastic centrifuge tube; After the volume was adjusted with pure water, centrifugation was performed with a centrifuge, and the supernatant was taken into a PFA dissolving sample jar; The PFA dissolving sample jar was placed on an electric heating plate to be heated and evaporated, then HF was added for redissolving, and the operation was repeated twice, finally the dissolving solution was adjusted to 2-3 mL of 1 M HF solution for column loading.

10. The method according to any one of claims 1 to 5, characterized in that, The step five comprises: a cup structure for static determination of Ge isotopes was established; determination of Ge isotopes by MC-ICP-MS was performed according to the cup structure; Ge content was obtained according to the determined Ge isotopes.

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