A method for detecting isotopic abundance of sulfur hexafluoride
By separating and detecting sulfur hexafluoride isotope peaks using gas chromatography-mass spectrometry (GC-MS), the problems of slow detection speed and high cost in existing technologies are solved, providing a rapid and efficient method for isotope abundance detection, achieving high accuracy and economy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI INSTITUTE OF APPLIED PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2025-09-26
- Publication Date
- 2026-06-26
AI Technical Summary
Existing isotope ratio mass spectrometers (IRMS) have drawbacks in detecting the abundance of sulfur hexafluoride (SF6) isotopes, such as large instrument size, high price, slow analysis speed, and long time consumption, which make it difficult to meet the needs of rapid and efficient detection.
The abundance of sulfur hexafluoride isotopes was detected using gas chromatography-mass spectrometry (GC-MS). The peaks of 32SF5+, 33SF5+, and 34SF5+ were separated and detected using a DB-5MS capillary column and specific mass spectrometry conditions. The abundance was calculated using the area normalization method.
A rapid, economical, and highly accurate isotope abundance detection method was achieved, with stable and repeatable results and a detection limit of 15.6 ppm.
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Figure CN120927865B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of analytical detection technology, specifically relating to a method for detecting the abundance of sulfur hexafluoride isotopes. Background Technology
[0002] Sulfur hexafluoride (SF6) is an extremely stable inert gas that plays a vital role in the power industry, semiconductor manufacturing, and industrial equipment due to its unique physical and chemical properties. The sulfur element in the SF6 molecule exists in several stable isotopes, such as... 32 S, 33 S, 34 The abundance differences of these isotopes can provide evidence for tracing the source and migration pathways of SF6. The detection of SF6 isotopic abundance can be used in environmental monitoring and climate change research, volcanic and geological activity tracking, and lunar soil elemental analysis for tracing origins. In environmental monitoring, SF6 isotopic analysis helps trace the sources of greenhouse gases and assess their impact on climate change. In geology, the isotopic characteristics of SF6 can be used to track volcanic activity and geological processes.
[0003] Currently, the main methods for detecting isotope abundance include isotope ratio mass spectrometry, photoacoustic spectroscopy, tunable semiconductor laser absorption spectroscopy, cavity ring-down spectroscopy, and cavity-enhanced absorption spectroscopy. Among these, isotope ratio mass spectrometry (IRMS) is the most widely used method for gas isotope analysis, offering high accuracy and sensitivity. However, IRMS also suffers from drawbacks such as large instrument size, high cost, slow analysis speed, and long processing time. Summary of the Invention
[0004] In view of this, the present invention provides a method for detecting the abundance of sulfur hexafluoride isotopes. The method provided by the present invention uses a gas chromatography-mass spectrometry (GC-MS) instrument, the detection steps are simple, the detection results can be obtained quickly, the detection efficiency is improved, and the detection results have high accuracy.
[0005] To address the aforementioned technical problems, this invention provides a method for detecting the abundance of sulfur hexafluoride isotopes, comprising the following steps:
[0006] The analyte was analyzed using gas chromatography-mass spectrometry (GC-MS) to obtain a total ion chromatogram of sulfur hexafluoride. The GC-MS test conditions included: DB-5MS capillary column, split ratio of 20-100:1, and injection volume of 1-10 µL. The mass spectrometry test conditions included: multiplier voltage of +300 to +600 rpm and full width at half maximum (FWHM) of less than 0.6.
[0007] Extracting ions from the total ion chromatogram of the sulfur hexafluoride 32 SF5 + , 33 SF5 + and34 SF5 + , respectively obtained 32 SF5 + , 33 SF5 + and 34 SF5 + The peak area was calculated. 32 SF5 + , 33 SF5 + and 34 SF5 + The abundance of.
[0008] Preferably, the calculation method includes area normalization.
[0009] Preferably, the gas chromatography test conditions further include: an initial column temperature of 30~60℃, a programmed temperature increase to 200℃ at a rate of 5~12℃ / min, a detector temperature of 220℃, a carrier gas of helium with a purity of 99.999%, and a valve cut-off gas of nitrogen with a mass concentration of 99.999%.
[0010] Preferably, the gas chromatography test conditions are as follows: the chromatographic column is a DB-5MS capillary column, the initial column temperature is 30~50℃, the temperature is programmed to rise to 200℃ at a rate of 10~12℃ / min, the detector temperature is 220℃; the split ratio is 50~80:1, the injection volume is 5~8µL; the carrier gas is helium with a purity of 99.999%; the valve cut-off gas is nitrogen with a mass concentration of 99.999%.
[0011] Preferably, the mass spectrometry testing conditions further include: an ion source with an ionization energy of -70 eV; a temperature of 235~245℃ for the ion source and a temperature of 245~255℃ for the transmission line; and a scan range of 1.5~300 amu.
[0012] Preferably, the mass spectrometry test conditions include: ion source, multiplier voltage +400, half-width at half maximum (WHM) of 0.58; ionization energy -70 eV; ion source temperature of 240 °C, transfer line temperature of 250 °C; and scan range of 1.5~300 amu.
[0013] Preferably, the sample to be tested includes gaseous test samples used in environmental monitoring and climate change research to test the abundance of sulfur isotopes.
[0014] Preferably, the gas chromatography-mass spectrometry (GC-MS) instrument includes the Celian SCION 436i-eSQ.
[0015] Preferably, the detection limit of the detection method is 15.6 ppm.
[0016] This invention provides a method for detecting the abundance of sulfur hexafluoride isotopes, comprising the following steps: detecting the sample using gas chromatography-mass spectrometry (GC-MS) to obtain a total ion chromatogram of sulfur hexafluoride; GC-MS testing conditions include: a DB-5MS capillary column, a split ratio of 20–100:1, and an injection volume of 1–10 µL; GC-MS testing conditions include: a multiplier voltage of +300–+600 rpm and a full width at half maximum (FWHM) of less than 0.6; and extracting ions from the total ion chromatogram of sulfur hexafluoride. 32 SF5 + , 33 SF5 + and 34 SF5 + , respectively obtained 32 SF5 + , 33 SF5 + and 34 SF5 + The peak area was calculated. 32 SF5 + , 33 SF5 + and 34 SF5 + The abundance of SF6. In this invention, isotopes in SF6 32 S, 33 S and 34 S loses one F after being bombarded by an ion source. - form 32 SF5 + , 33 SF5 + and 34 SF5 + This invention utilizes gas chromatography-mass spectrometry (GC-MS) to effectively separate and accurately detect gases under specific conditions. 32 SF5 + , 33 SF5 + , 34 SF5 + This invention provides a highly efficient and economical detection method for detecting specific isotope peaks. The detection method provided by this invention has the advantages of being economical, having a fast analysis speed, and high accuracy. Attached Figure Description
[0017] Figure 1 The total ion chromatogram of SF6 standard gas obtained in Example 1;
[0018] Figure 2 The total ion chromatogram of SF6 standard gas obtained in Example 2;
[0019] Figure 3The total ion chromatogram of SF6 standard gas obtained in Comparative Example 2 is shown. Detailed Implementation
[0020] This invention provides a method for detecting the abundance of sulfur hexafluoride isotopes, comprising the following steps:
[0021] The analyte was analyzed using gas chromatography-mass spectrometry (GC-MS) to obtain a total ion chromatogram of sulfur hexafluoride. The GC-MS test conditions included: DB-5MS capillary column, split ratio of 20-100:1, and injection volume of 1-10 µL. The mass spectrometry test conditions included: multiplier voltage of +300 to +600 rpm and full width at half maximum (FWHM) of less than 0.6.
[0022] Extracting ions from the total ion chromatogram of the sulfur hexafluoride 32 SF5 + , 33 SF5 + and 34 SF5 + , respectively obtained 32 SF5 + , 33 SF5 + and 34 SF5 + The peak area was calculated. 32 SF5 + , 33 SF5 + and 34 SF5 + The abundance of.
[0023] This invention utilizes gas chromatography-mass spectrometry (GC-MS) to detect the sample and obtain a total ion chromatogram of sulfur hexafluoride. In this invention, the sample may include gaseous samples used for sulfur isotope abundance testing in environmental monitoring and climate change research; the GC-MS may include a Celian SCION 436i-eSQ.
[0024] In this invention, the pre-detection process may further include: sequentially performing vacuum treatment and mass spectrometry tuning on the gas chromatography-mass spectrometry instrument; this invention does not have a special limitation on the vacuum degree of the vacuum treatment, as long as it meets the vacuum conditions for instrument use; the vacuum treatment time can be 5~26h, specifically 24h.
[0025] In this invention, the gas chromatography testing conditions of the gas chromatography-mass spectrometry (GC-MS) instrument include: a DB-5MS capillary column, a split ratio of 20~100:1, and an injection volume of 1~10 μL. µL; the gas chromatography test conditions may further include: an initial column temperature of 30~60℃, programmed temperature increase to 200℃ at a rate of 5~12℃ / min, a detector temperature of 220℃, helium as the carrier gas with a purity of 99.999%; and nitrogen as the valve cut-off gas with a mass concentration of 99.999%; the gas chromatography test conditions may also include: a DB-5MS capillary column, an initial column temperature of 30~50℃, programmed temperature increase to 200℃ at a rate of 10~12℃ / min, a detector temperature of 220℃; a split ratio of 50~80:1, an injection volume of 5~8µL; helium as the carrier gas with a purity of 99.999%; and nitrogen as the valve cut-off gas with a mass concentration of 99.999%.
[0026] In this invention, the mass spectrometry testing conditions of the gas chromatography-mass spectrometry (GC-MS) instrument include: an electron impact ion source, a multiplier voltage of +300 to +600 ohms, and a full width at half maximum (FWHM) of less than 0.6. The mass spectrometry testing conditions may also include: an ion source, an ionization energy of -70 eV, an ion source temperature of 235 to 245°C, a transfer line temperature of 245 to 255°C, and a scan range of 1.5 to 300 amu. Alternatively, the mass spectrometry testing conditions may be: an ion source, a multiplier voltage of +400 ohms, a FWHM of 0.58, an ionization energy of -70 eV, an ion source temperature of 240°C, a transfer line temperature of 250°C, and a scan range of 1.5 to 300 amu.
[0027] After obtaining the total ion chromatogram of sulfur hexafluoride, the present invention extracts ions from the total ion chromatogram of sulfur hexafluoride. 32 SF5 + , 33 SF5 + and 34 SF5 + , respectively obtained 32 SF5 + , 33 SF5 + and 34 SF5 + The peak area was calculated. 32 SF5 + , 33 SF5 + and 34 SF5 + The abundance of [the resource / information]. In this invention, the calculation method may include area normalization.
[0028] In this invention, the detection limit of the sulfur hexafluoride isotope abundance detection method is 15.6 ppm.
[0029] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0030] Example 1
[0031] The SF6 standard gas (SF6 mass percentage content of 0.997%) purchased from Dalian Date Gas Co., Ltd. with standard substance number BW(DT)0116 was used as the test sample for detection.
[0032] A Celian SCION 436i-eSQ gas chromatography-mass spectrometry (GC-MS) system was vacuum-treated for 24 hours before mass spectrometry tuning. The calibrated GC-MS system was used to analyze the sample, yielding a total ion chromatogram of sulfur hexafluoride. GC-MS conditions included: a DB-5MS capillary column, initial column temperature 30℃, programmed temperature ramp to 200℃ at 10℃ / min, detector temperature set to 220℃, split ratio 80:1, injection volume 5 µL, and 99.999% pure helium as carrier gas; the valve cut-off gas was 99.999% nitrogen. Mass spectrometry conditions included: ion source, ionization energy -70 eV, full width at half maximum (FWHM) 0.58; multiplier voltage +400V; and ion source and transfer line temperatures set to 240℃ and 250℃, respectively.
[0033] Total ion chromatogram of sulfur hexafluoride 32 SF5 + , 33 SF5 + and 34 SF5 + The extracted ions were obtained separately. 32 SF5 + , 33 SF5 + and 34 SF5 + The peak area was calculated using the area normalization method. 32 SF5 + , 33 SF5 + and 34 SF5 + abundance;
[0034] The total ion chromatogram of sulfur hexafluoride obtained from SF6 standard gas is as follows: Figure 1 As shown.
[0035] Example 2
[0036] The detection was performed according to the method in Example 1, with the following differences: the gas chromatography test conditions included: a DB-5MS capillary column, an initial column temperature of 30°C, a programmed temperature ramp to 200°C at a rate of 10°C / min, a detector temperature set to 220°C, a split ratio of 50:1, an injection volume of 10 µL, and helium gas with a purity of 99.999% as the carrier gas; the extracted ions were calculated to obtain... 32 SF5 + , 33 SF5 + and 34 SF5 + Abundance results;
[0037] The total ion chromatogram of sulfur hexafluoride obtained from SF6 standard gas is as follows: Figure 2 As shown.
[0038] Comparative Example 1
[0039] The detection was performed according to the method of Example 1, except that SF6 standard gas with standard substance number BW(DT)0116 purchased from Dalian Date Gas Co., Ltd. was used as the test sample.
[0040] Gas chromatography test conditions included: DB-624 column, initial column temperature 30℃, programmed temperature ramp to 200℃ at a rate of 10℃ / min, detector temperature set to 220℃, split ratio of 20:1, injection volume of 10 µL, and helium gas with a purity of 99.999% as carrier gas; mass spectrometry test conditions included: electron impact ionization source, ionization energy -70 eV; multiplier voltage -1190 eV; and ion source and transfer line temperatures set to 240℃ and 250℃, respectively.
[0041] Comparative Example 2
[0042] The detection was performed according to the method of Comparative Example 1, except that the gas chromatography test conditions included: ; the mass spectrometry test conditions included: electron impact ion source, ionization energy -70eV; multiplier voltage +400; and the temperatures of the ion source and the transfer line were set to 240℃ and 250℃, respectively.
[0043] The total ion chromatogram of sulfur hexafluoride obtained from SF6 standard gas is as follows: Figure 3 As shown.
[0044] The total ion chromatogram of sulfur hexafluoride obtained in Comparative Example 1 showed flat-top and tailing phenomena in the chromatographic peaks; preliminary analysis indicated that the flat-top phenomenon was related to the excessively high peak intensity.
[0045] Depend on Figure 3 It can be seen that the retention time of the chromatographic peak of sulfur hexafluoride in Comparative Example 2 is 3.947 min, the peak shape has been improved and the flat-top phenomenon has disappeared, but the tailing phenomenon still exists.
[0046] Depend on Figure 1 and 2 It can be seen that the tailing phenomenon disappeared after changing the chromatographic column. The retention times of the sulfur hexafluoride peak in Examples 1 and 2 were shortened to 1.255 min and 1.261 min, respectively. In Example 1, the injection volume was reduced from 10 µL to 5 µL. Figure 1 The peak intensity was further reduced, which improved the chromatographic peak shape and resulted in good separation and suitable peak intensity.
[0047] Test Example 1
[0048] The SF6 standard gas was tested five times according to the method in Example 1, and the results are listed in Table 1.
[0049] Table 1. Comparison of results from 5 repeated tests with standard values.
[0050]
[0051] As can be seen from Table 1, after five repeated experiments, the results are as follows: 32 SF5 + , 33 SF5 + , 34 SF5 + The abundance precision (in terms of relative standard deviation) of the three factors, accounting for the sum of the three, were 0.02%, 1.20%, and 0.53%, respectively, all within a reasonable range, indicating good repeatability of the five experiments. Table 1 shows that in the five tests... 32 SF5 + The average relative error is 0.15%. 33 SF5 + The average relative error was 5.48%. 34 SF5 + The average relative error is 3.72%. The detection results provided by this invention are very stable with a small relative error. 33 SF5 + The detection results had a relatively large error, mainly because of the presence of [unclear text - possibly a continuation of a previous sentence] in the standard gas. 33 The abundance of S was low (0.763%), resulting in a weak detection signal, but still within an acceptable range. Overall, the detection method provided by this invention is effective for detecting SF6. 32 S, 33 S and 34 The detection of S isotope abundance exhibits good repeatability, stability, and accuracy.
[0052] This invention utilizes gas chromatography-mass spectrometry (GC-MS) to detect SF6 under specific detection conditions. 32 SF5 + , 33SF5 + and 34 SF5 + The isotope abundance detection exhibited good repeatability, stability, and accuracy, validating the applicability of gas chromatography-mass spectrometry (GC-MS) in SF6 isotope abundance detection. The detection method provided by this invention enables accurate measurement of isotope abundance in SF6 and verifies that the detection limit of GC-MS meets the requirements for precise measurement of isotope abundance in SF6. This provides an efficient and economical detection method and reliable technical support for isotope abundance detection, and lays a solid data foundation for subsequent experiments.
[0053] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. A method for detecting the abundance of sulfur hexafluoride isotopes, characterized in that, Includes the following steps: The total ion chromatogram of sulfur hexafluoride was obtained by using a gas chromatography-mass spectrometry (GC-MS) instrument. Gas chromatography test conditions include: DB-5MS capillary column, initial column temperature 30℃, programmed temperature ramp to 200℃ at a rate of 10℃ / min, detector temperature 220℃; split ratio 50~80:1, injection volume 5~10µL; mass spectrometry test conditions include: multiplier voltage +300~+600V, half maximum width at half maximum (WHM) below 0.
6. Extracting ions from the total ion chromatogram of the sulfur hexafluoride 32 SF5 + , 33 SF5 + and 34 SF5 + , respectively obtained 32 SF5 + , 33 SF5 + and 34 SF5 + The peak area was calculated. 32 SF5 + , 33 SF5 + and 34 SF5 + The abundance of.
2. The method for detecting the abundance of sulfur hexafluoride isotopes according to claim 1, characterized in that, The calculation method includes area normalization.
3. The method for detecting the abundance of sulfur hexafluoride isotopes according to claim 1, characterized in that, The gas chromatography test conditions are as follows: the injection volume is 5~8µL; the carrier gas is helium with a purity of 99.999%; the valve cut-off gas is nitrogen with a mass concentration of 99.999%.
4. The method for detecting the abundance of sulfur hexafluoride isotopes according to claim 1, characterized in that, The mass spectrometry testing conditions also include: an ion source with an ionization energy of -70 eV; a temperature of 235~245℃ for the ion source and a temperature of 245~255℃ for the transmission line; and a scanning range of 1.5~300 amu.
5. The method for detecting the abundance of sulfur hexafluoride isotopes according to claim 4, characterized in that, The mass spectrometry test conditions included: ion source, multiplier voltage +400V, half maximum width at half maximum (WWHM) of 0.58; ion source temperature of 240℃, transfer line temperature of 250℃; and scan range of 1.5~300 amu.
6. The method for detecting the abundance of sulfur hexafluoride isotopes according to claim 1, characterized in that, The samples to be tested include gaseous test samples used in environmental monitoring and climate change research to test the abundance of sulfur isotopes.
7. The method for detecting the abundance of sulfur hexafluoride isotopes according to claim 1, characterized in that, The gas chromatography-mass spectrometry (GC-MS) instrument includes the Celian SCION 436i-eSQ.
8. The method for detecting the abundance of sulfur hexafluoride isotopes according to any one of claims 1 to 7, characterized in that, The detection limit of the detection method is 15.6 ppm.