Impact of Sampling Containers on the Analytical Results of Helium-Bearing Natural Gas

Impact of Sampling Containers on the Analytical Results of Helium-Bearing Natural Gas | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Impact of Sampling Containers on the Analytical Results of Helium-Bearing Natural Gas Xinxin Fang, Kun Yuan, Xuemin Xu, Jiajia Yang, Yinbo Xu, Shujing Bao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7524670/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Mar, 2026 Read the published version in Discover Sustainability → Version 1 posted 12 You are reading this latest preprint version Abstract Helium is a critical strategic resource that underpins high-tech industries and national security. The accuracy of its concentration measurement is essential for reliable helium resource exploration and evaluation. Due to its small molecular size (0.26 nm), high diffusion coefficient, and typical occurrence in trace amounts (< 1%) in natural gas, helium poses significantly greater challenges for sample collection and storage compared to conventional natural gas. Thus, the selection of storage containers is a crucial factor influencing detection accuracy. However, systematic studies comparing the performance of commonly used containers—such as dual-valve high-pressure steel cylinders and aluminum-plastic gas bags—for storing helium-bearing natural gas are still lacking. This study systematically evaluated these two container types through controlled experiments. The immediate comparative experiment involved parallel sampling from the same gas source using both containers, followed by prompt component analysis to compare initial detection results. The time-sensitive experiment monitored compositional changes in samples stored in both containers over 7, 15, and 30 days to assess preservation performance and variation in helium concentration over time. Variables including gas source, sampling pressure (2.0 ± 0.1 MPa), and purging cycles (4 times) were strictly controlled to ensure result reliability. Results revealed that during immediate detection, both containers showed consistent helium content, with an average relative deviation of 1.9%. However, concentrations of air components such as N2 and O 2 were significantly higher in aluminum-plastic airbags—O 2 levels in some samples reached 35.9 to 87.5 times those in steel cylinders. In the time-sensitive experiment, steel cylinders demonstrated excellent stability, with a helium decay rate of only 12.0%~14.4% over 30 days. In contrast, aluminum-plastic airbags exhibited severe helium loss, with decay rates ranging from 14.4–78.7%. Some samples nearly completely lost helium after 15 days. Furthermore, hydrocarbon components (e.g., CH 4 ) decreased sharply in aluminum-plastic airbags—with a decay rate of up to 88.1% within 30 days—while air component concentrations increased by 18.9 to 63 times. In conclusion, dual-valve high-pressure steel cylinders, with their superior airtightness and chemical stability, outperform aluminum-plastic airbags significantly in storing helium-bearing natural gas. They are recommended as the preferred container for long-term (> 15 days) storage and high-precision helium detection. Aluminum-plastic airbags are only suitable for short-term (< 7 days) temporary storage and require strict monitoring of air contamination risks. This study provides key data support for optimizing helium-bearing natural gas detection protocols and enhancing the reliability of helium resource assessment. Helium gas Storage containers Steel cylinder Aluminum-plastic airbag Helium content test Figures Figure 1 Figure 2 Figure 3 1. Introduction Helium is a key strategic rare gas vital to national security and the development of high-tech industries. Owing to its unique physical and chemical properties—such as low boiling point, high thermal conductivity, and strong chemical inertness—it is irreplaceable in cutting-edge fields including deep space exploration, low-temperature superconductivity, large-scale scientific facilities, semiconductor manufacturing, and high-end medical equipment [ 1 , 2 ]. The global distribution of helium resources is highly uneven. China has long relied heavily on imports, with an external dependency rate exceeding 90%. Although significant helium-rich natural gas reservoirs have recently been discovered in basins such as Ordos and Tarim, along with water-soluble helium resources in the Qaidam and Weihe Basins [ 3 – 8 ], the accurate development and utilization of these resources rely heavily on highly reliable detection data. In fact, the entire process of helium resource exploration and evaluation depends critically on the precision of such data. Helium possesses distinct molecular characteristics. These include the smallest molecular diameter (only 0.26 nm), a high diffusion coefficient in gases, and trace concentrations in natural gas, typically below 1%. These properties make it highly susceptible to loss and contamination throughout sampling, storage, and detection. Such challenges are far more pronounced than those associated with conventional hydrocarbon components. As a result, stringent quality control across the entire detection process is essential [ 9 , 10 ]. Among the numerous factors influencing the accuracy of trace helium detection, the choice of sampling containers is regarded as one of the key potential sources of error [ 11 – 13 ]. Currently, different researchers have carried out a series of studies on gas sampling containers. Dual-valve high-pressure steel cylinders are widely considered the preferred vessels for high-precision gas sampling due to their extremely low permeability (< 0.001%/year) and superior sealing performance [ 14 – 17 ]. On the other hand, although aluminum-plastic airbags offer advantages such as light weight and low cost, their material may lack sufficient barrier properties against light gases like He and H 2 . This can easily lead to distortion of sample composition through adsorption, permeation, and other effects, thereby introducing considerable deviations in detection results [ 18 , 19 ]. While existing studies have addressed performance differences among storage containers, most have focused on common gases or high-concentration components [ 20 – 22 ]. There remains a lack of systematic comparative research on the short- and medium-term stability of trace helium in commercially used containers such as steel cylinders and aluminum-plastic airbags. Furthermore, empirical data under real helium-bearing natural gas conditions are insufficient. In addition, most current natural gas analysis standards are designed for hydrocarbons and high-concentration non-hydrocarbon components, making them poorly suited to the trace characteristics of helium. As a result, there is no clear and reliable regulatory guideline for selecting storage containers in helium-bearing natural gas detection [ 23 – 25 ]. To clarify how storage containers affect the test results of helium-bearing natural gas, this study designed and carried out two sets of comparative experiments. These experiments systematically evaluate the ability of dual-valve high-pressure steel cylinders (hereinafter referred to as steel cylinders) and aluminum-plast airbags to maintain sample integrity, and their impact on detection reliability throughout the sampling, storage, and transportation processes. The first experiment is an immediate comparative experiment. Both steel cylinders and aluminum-plastic airbags were used to collect parallel samples from the same gas source. These samples were analyzed immediately to compare differences in the initial test results. The second experiment is a time-sensitive experiment. Samples stored in both types of containers were analyzed after different storage periods. This was done to evaluate the preservation performance of each container type and to observe changes in helium concentration over time. The ultimate goal of this study is to provide essential data support and a theoretical basis for improving the accuracy of helium-bearing natural gas resource evaluation and for refining related detection standards. 2 Materials and Methods 2.1 Experimental Materials and Equipment 2.1.1 Sampling containers In this study, dual-valve high-pressure steel cylinders and aluminum-plastic airbags were selected as comparative storage container. Both are widely used gas sampling containers in industrial and scientific research fields [ 26 – 28 ], but there are significant differences in their material, structure, and physicochemical properties, which is also the fundamental reason for the differences in their gas preservation performance. (1) Dual-valve high-pressure steel cylinders The steel cylinders used in this experiment are made of 316 stainless steel and have a nominal volume of 2L. This material offers excellent chemical inertness and corrosion resistance, effectively preventing reactions with trace corrosive components (e.g., H 2 S, CO 2 ) in helium-bearing natural gas and helping maintain the chemical integrity of the samples. The inner walls of the cylinders have been mechanically polished and passivated, significantly reducing surface adsorption of gas molecules (especially trace components). A key feature is the dual-valve design with metal-face seals, which allows rapid gas filling and discharging while ensuring high sealing integrity and an extremely low leakage rate. Owing to its high pressure resistance (with a working pressure up to 20 MPa) and extremely high density of 316 stainless steel, the cylinders are nearly impermeable to small gas molecules such as helium. These properties make them the preferred container for high-precision gas sampling and long-term storage [ 29 , 30 ]. (2) Dual-valve aluminum-plastic airbags The aluminum-plastic airbag is made of multiple layers of composite film, with a typical structure of an outer layer (nylon film), a barrier layer (aluminum foil), and an inner layer (polyethylene PE). The airbags used in this experiment have a nominal volume of 500 mL, with the aluminum foil barrier layer having a thickness of approximately 12 µm. A sealed chamber is formed through a thermal fusion process, and two one-way plastic valve nozzles are equipped for gas filling and venting. The aluminum foil layer acts as the primary barrier structure, which can partially inhibit the rapid permeation of light gases such as helium. However, its barrier performance is considerably lower than that of steel cylinders [ 31 – 33 ]. Although this type of airbag offers advantages such as good flexibility and light weight, it has poor mechanical strength and pressure resistance, making it susceptible to damage or leakage from punctures and compression. Furthermore, during long-term storage, the polymer materials are prone to aging. If the aluminum foil layer is damaged, it will further exacerbate the slow leakage of gases (especially helium) through microscopic defects. Therefore, it is often used for temporary gas sampling and storage with low precision requirements and short cycles [ 34 ]. 2.1.2 Gas source The gas used in this experiment was sourced from a natural gas field located in the eastern Ordos Basin, China. The primary gas-producing intervals in this field are the Middle Ordovician Majiagou Formation and the Permian Shanxi Formation [ 35 – 38 ], which form a proven helium-bearing natural gas reservoir. The background helium content of the natural gas samples ranges from 200 ppm to 1000 ppm [ 39 ]. This concentration range is representative of the typical trace helium levels found in most helium-bearing natural gas reservoirs in China [ 40 – 42 ], making the experimental conclusions of this study representative. In addition to helium, the main component of this natural gas is methane (CH 4 ), which also contains a certain amount of heavy hydrocarbons such as nitrogen (N 2 ) and ethane (C 2 H 6 ), as well as trace amounts of non hydrocarbon components. This gas source was selected due to its stable and well-characterized helium content, which provides a reliable basis for comparing the preservation behavior of trace helium across different storage containers. All comparative experiments were performed using natural gas samples collected from the same gas source and in the same batch to ensure experimental consistency and minimize the impact of source variability on the results. 2.1.3 Analytical Instruments Qualitative and quantitative analysis of the components in helium-bearing natural gas was conducted at the National Research Center for Geoanalysis. The core analytical instrument used was an Agilent 7890B gas chromatograph, equipped with one hydrogen flame ionization detector (FID) and two thermal conductivity detectors (TCD). The FID was employed for high-sensitivity detection of C 1 ~ C 5 hydrocarbon gases. One of the TCD detectors was specifically optimized for quantitative analysis of permanent gases—including He, H 2 , N 2 and O 2 —due to its high response to helium. This detector configuration enables simultaneous and accurate analysis of both trace helium and conventional gas components. The analytical procedure strictly adhered to the Chinese national standard GB/T 13610 − 2020 (Natural Gas Analysis by Gas Chromatography). To achieve precise detection of trace helium and avoid interference from component co-elution, key parameters were optimized as follows: (1) The injection port was operated in split mode (split ratio 5:1) at 250℃ to balance detection sensitivity and column load. (2) A parallel dual-column configuration was used, consisting of a 3-ft HayeSep Q column and an 8-ft 5Å molecular sieve column. (3) The temperature program was set as: hold at 60 ℃ for 1 min → ramp to 80℃ at 20℃/min → ramp to 190 ℃ at 30 ℃/min and hold for 2 min. This method ensured baseline separation of He from H 2 , N 2 and other components (separation factor > 1.5). The instrument’s limit of detection (LOD) for He was below 5 ppm, and the analytical accuracy, expressed as relative standard deviation (RSD), was better than ± 2%. Quantitative analysis was performed using an external standard method. A calibration curve was constructed using a mixture of standard gases with three or more concentration levels covering He, CH 4 , H 2 and CO 2 (He concentration range: 0.003–10%). The correlation coefficient ( R 2 ) exceeded 0.9995. A sample volume of 450 µL was injected, enabling simultaneous quantification of C 1 ~ C 5 , C 6 + hydrocarbons, and non-hydrocarbon components including He, H 2 , CO 2 , CO, N 2 and O 2 . The quantification limit for He was 0.01% (mol/mol). For quality control, every batch of 10 samples included one duplicate and one standard gas sample. The relative deviation of component response values in the standard gas was required to be ≤ 1%. All replicate measurements complied with the precision criteria specified in GB/T 13610 − 2020 [ 43 ]. 2.2. Experimental Methods 2.2.1 Sampling process To ensure high comparability among samples originating from the same gas source and minimize the introduction of extraneous variables during sampling, this study followed a strict standardized sampling protocol. Sampling was performed at the pressure gauge interface downstream of the wellhead separator (Fig. 1 ) to guarantee sample representativeness. The standardized procedure is described as follows: (1) System purging and preparation The gas source valve was closed and the vent valve opened to release residual gas from the pipeline. After removing the pressure gauge, the gas source valve was slowly reopened, allowing high-velocity gas flow to flush the interface for 10 ~ 15 seconds to eliminate impurities and residual air. (2) Connection and leak testing One end of the sampling line was connected to the purged sampling port, and the other end was sealed to the inlet valve of the sampling container (either a dual-valve high-pressure steel cylinder or an aluminum-plastic airbag). After connection, a leak test was performed to ensure all interfaces were airtight. (3) Container and Line Purging (Replacement) This step is critical for ensuring sample purity. The inlet valve of the sampling container was opened, followed by slowly opening the gas source valve. ①For dual-valve steel cylinders: the outlet valve was opened to vent gas from the container and line until zero pressure was reached for 10 ~ 15 seconds, after which the outlet valve was closed. This process was repeated four times. ②For aluminum-plastic airbags: purging was achieved through repeated inflation and deflation. The bag was filled with gas, then squeezed to expel the gas. This cycle was repeated four times. (4) Sample Filling After completing the required number of purging cycles, sample filling was conducted under stable gas source pressure. ①For steel cylinders: the outlet valve was closed, and the cylinder was filled until pressure stabilized at the target value. The inlet valve was then closed. ②For aluminum-plastic airbags: inflation continued until the bag reached its nominal volume. The gas source valve was then closed, and the connection promptly disconnected. (5) Final Step The gas source valve was closed, and the sampling line was depressurized. After disconnecting the sampling container, it was immediately labeled with key information such as sampling time and gas source number. Throughout the sampling process, all samples were collected from the same port using the same sampling line under consistent gas source pressure. The number of purging cycles was strictly maintained at four for all samples. These measures minimized systematic errors during sampling, ensuring that any observed differences in gas composition could be primarily attributed to the properties of the storage containers themselves. 2.2.2 Experimental design To systematically evaluate the impact of storage containers on the test results of helium-bearing natural gas, this study designed two sets of comparative experiments. All experiments were conducted under constant temperature (25 ± 1℃) and humidity (relative humidity 50 ± 5%) laboratory conditions to eliminate interference from environmental factors. (1) Experiment 1: Immediate Comparative Experiment This experiment aimed to determine whether different storage containers introduce immediate systematic deviations in initial helium detection results under strictly standardized sampling procedures, thereby evaluating the inherent reliability of each container type during sampling. Samples were collected simultaneously from the same gas source, at the same sampling point, and at the same time. Parallel sampling was performed using dual-valve high-pressure steel cylinders and aluminum-plastic airbags, each subjected to four standardized “filling-evacuation” replacement cycles. A total of nine natural gas samples from different drilling wells were collected to improve statistical significance. Controlled variables included sampling pressure (2.0 ± 0.1MPa), connecting pipelines, purge cycles, and operating personnel. All sealed samples were transported to the same laboratory within 10 days and analyzed using an Agilent 7890B gas chromatograph. The initial test results from the two container types were directly compared, with particular emphasis on differences in helium content. (2) Experiment 2: Time-Sensitive Experiment This experiment aimed to investigate the sample preservation capabilities of steel cylinders and aluminum-plastic airbags over different storage periods, with a focus on the decay behavior of trace helium concentration and the medium- to long-term preservation performance of each container. Samples were obtained from three drilling gas sources with varying helium background concentrations (approximately 0.02%, 0.04%, and 0.06%, mol/mol). From each source, multiple parallel sample sets (steel cylinder group and airbag group) were synchronously prepared using the standardized sampling procedure, with three replicates per group to assess repeatability and error. All filled and sealed samples were stored under identical protected conditions. Subsets of samples were retrieved and analyzed at predetermined intervals: immediately upon delivery, and after 7, 15, and 30 days of storage. The helium concentration was measured at each time point, and the decay rate was calculated as: Decay Rate (%) = [(Initial Concentration – Concentration at Day T) / Initial Concentration] × 100, Concentration-time curves and decay rate charts were generated to systematically analyze helium loss trends in each container type. 3. Results and Discussion 3.1 Results 3.1.1 Results of the immediate comparative experiment The immediate comparative experiment evaluated the initial capture reliability of two storage containers for various components of helium-bearing natural gas by systematically analyzing parallel-collected samples from the same gas source. The results indicate that although both containers show good consistency for major target components, significant differences exist in the permeation of air components. (1) Consistency of hydrocarbon gas components Concentrations of hydrocarbon gases—such as CH 4 , C 2 H 6 , C 3 H 8 —were highly similar in both steel cylinders and aluminum-plastic airbags (Fig. 2 (a-c)), with slightly higher values consistently observed in the steel cylinders. Specifically, the average CH 4 concentration across the nine samples was 94.08%±2.41% in the steel cylinder group and 91.99%±2.51% in the airbag group, yielding an average relative deviation of 2.2%. The largest discrepancy was observed in Sample 4, with values of 96.63% (cylinder) and 94.90% (airbag), representing an absolute difference of 1.73%. C 2 H 6 exhibited even stronger consistency: both containers measured 0.21% in Sample 1, and values of 2.79% (cylinder) and 2.65% (airbag) were recorded in Sample 7, corresponding to a relative deviation of only 5.0%. C 3 H 8 was identical (0.08%) in both Sample 2 and Sample 3. These results demonstrate that, under strictly controlled sampling conditions, both containers offer equivalent initial preservation performance for hydrocarbon gases. (2) Comparative analysis of helium concentration For trace helium, the two containers showed good correlation but systematic differences (Fig. 2 (e)). The helium concentration ranged from 177.55 to 865.54 ppm (avg. 488.99 ppm) in steel cylinders and from 213.38 to 819.06 ppm (avg. 479.88 ppm) in airbags. In seven of the nine samples, airbag values were lower than those from cylinders, with an average deviation of -1.9%. The largest difference occurred in Sample 5 (865.54 ppm vs. 819.06 ppm; relative deviation 5.4%), while the smallest was in Sample 2 (647.30 ppm vs. 650.25 ppm; relative deviation 0.5%). This pattern suggests that even under immediate detection conditions, aluminum-plastic airbags may allow slight helium permeation loss or dilution. Table 1 Comparison of gas content between dual-valve high-pressure steel cylinder and aluminum-plastic airbag (a) Gas content of dual-valve high-pressure steel cylinder in the immediate comparative experiment Gas components Samples in steel cylinder Sample1 Sample2 Sample3 Sample4 Sample5 Sample6 Sample7 Sample8 Sample9 CH 4 /% 92.57 94.31 89.68 96.63 94.74 94.30 95.01 92.15 95.86 C 2 H 6 /% 0.21 0.50 0.62 0.83 0.56 0.61 2.79 0.39 1.22 C 3 H 8 /% 0.02 0.08 0.08 0.10 0.07 0.09 0.39 0.06 0.15 CO 2 /% 6.42 3.24 2.94 1.31 2.43 4.29 1.18 7.01 1.65 N 2 /% 0.71 1.75 6.60 0.97 2.06 0.06 0.49 0.12 1.00 O 2 /ppm 78.30 299.93 166.26 86.98 207.00 44.96 60.29 63.66 146.80 He /ppm 432.50 647.30 409.71 552.42 865.54 177.55 456.10 227.90 622.87 H 2 /ppm 221.72 190.67 149.46 213.04 220.16 2.24 191.04 2.24 114.55 (b) Gas content of aluminum-plastic airbag in the immediate comparative experiment Gas components Samples in aluminum-plastic airbag Sample1 Sample2 Sample3 Sample4 Sample5 Sample6 Sample7 Sample8 Sample9 CH4 /% 91.51 93.37 88.71 94.90 92.88 91.95 92.76 90.17 92.70 C2H6 /% 0.21 0.48 0.60 0.82 0.54 0.59 2.65 0.38 1.17 C3H8 /% 0.02 0.08 0.08 0.10 0.07 0.08 0.35 0.06 0.14 CO2 /% 6.37 3.00 2.83 1.21 2.34 4.17 1.11 6.77 1.58 N2 /% 1.55 2.66 7.37 2.39 3.53 0.84 1.87 0.92 1.90 O2 /ppm 2811.20 3204.64 3526.24 4819.27 5260.02 2606.82 5274.96 2668.44 3138.41 He /ppm 438.85 650.25 408.17 537.57 819.06 213.38 461.85 221.99 564.76 H2 /ppm 218.86 196.88 144.19 334.32 222.08 0.00 180.46 0.00 113.00 (3) Permeation of Air Components Differences in air components (N 2 , O 2 ) were most pronounced (Fig. 2 (g, h)). N 2 concentrations were generally elevated in airbags: in Sample 1, the airbag value (1.55%) was 2.2 times that in the cylinder (0.71%), and in Sample 6, it was 14 times higher (0.84% vs. 0.06%). O 2 differences were even more striking. In Sample 1, the O 2 concentration in the airbag (2811.20 ppm) was 35.9 times that in the cylinder (78.30 ppm). In Sample 7, the airbag value (5274.96 ppm) was 87.5 times the cylinder value (60.29 ppm) (Table 1 ), indicating severe air infiltration in aluminum-plastic airbags. (4) Other Components CO 2 concentrations showed relatively small differences between the two containers (Fig. 2 (d)), with an average relative deviation of 3.8%. H 2 exhibited more complex behavior (Fig. 2 (f)): H 2 was undetected (0.00 ppm) in airbags for Samples 6 and 8, whereas steel cylinders measured 2.24 ppm—suggesting possible adsorption of hydrogen by the aluminum-plastic material. In other samples, H 2 concentrations were relatively consistent, with an average relative deviation of 12.3%. 3.1.2 Results of the time-sensitive experiment The time-sensitive experiment systematically analyzed changes in gas composition within steel cylinders and aluminum-plastic airbags over time to evaluate the medium- and long-term storage performance of both container types. The results reveal significant differences in the preservation of gas components between the two containers, with these differences becoming more pronounced as storage duration increased. (1) Stability of hydrocarbon gas components Hydrocarbon gases (CH 4 , C 2 H 6 , C 3 H 8 ) in steel cylinders demonstrated excellent stability over the 30-day storage period (Fig. 3 (a-c)). For instance, in Sample 1, CH 4 concentration changed marginally from 95.59–95.99% (Table 2 ), representing a fluctuation of less than 0.5%. C 2 H 6 remained stable between 1.21% and 1.23%. In contrast, aluminum-plastic airbags exhibited severe hydrocarbon loss: CH 4 in Sample 1 decreased sharply from 92.70–11.04%, corresponding to a relative decay rate of 88.1%. C 2 H 6 also declined from 1.17–0.21%. Moreover, C 3 H 8 in Sample 3 displayed abnormal variation (from 0.36–391.85%, then down to 61.81%), suggesting possible sample contamination or analytical anomalies. (2) Helium preservation performance Marked differences were observed in helium preservation between the two containers. Helium concentration in steel cylinders decreased slowly and uniformly (Fig. 3 (e)): in Sample 1, it declined from 661.22 ppm to 582.09 ppm over 30 days (decay rate: 12.0%); in Sample 2, from 234.19 ppm to 200.37 ppm (decay rate: 14.4%). Helium loss was more severe in aluminum-plastic airbags: Sample 1 decreased from 664.76 ppm to 141.50 ppm (decay rate: 78.7%); Sample 2 decayed at 14.4%. Notably, in Sample 3, helium was nearly entirely lost after 15 days (from 456.07 ppm to 0.35 ppm), indicating major leakage or permeation issues. (3) Time-dependent permeation of air components Changes in air components (N 2 , O 2 ) further confirmed the permeation defects of aluminum-plastic airbags. N 2 and O 2 concentrations remained stable in steel cylinders throughout the experiment (Fig. 3 (g, h)): in Sample 1, O 2 held constant at 0.01%, and N 2 varied only between 0.96% and 1.00%. In aluminum-plastic airbags, however, air components increased substantially over time: O 2 in Sample 1 rose from 0.31–19.59% (a 63-fold increase), and N 2 increased from 1.90–35.94% (an 18.9-fold increase), demonstrating continuous infiltration of external air. (4) Variation patterns of other gases CO 2 remained stable in steel cylinders (e.g., Sample 1: 1.65%~1.68%) but decreased in airbags (Sample 1: 1.58–0.27%) (Fig. 3 (d)). H 2 exhibited more complex behavior: concentrations were stable in steel cylinders (Sample 1: 114.55–119.61 ppm) but declined steadily in airbags (Sample 1: 113.00 ppm to 0.00 ppm) (Fig. 3 (f)), suggesting possible adsorption or catalytic reaction with the airbag material. (5) Variability across samples Different samples responded differently to storage conditions. For example, the helium decay rate in Sample 2 (14.4%) was much lower than that in Sample 1 (78.7%) when stored in airbags, possibly due to variations in initial composition, micro-environmental conditions, or individual container differences. Overall, however, the preservation performance of aluminum-plastic airbags remained significantly inferior to that of steel cylinders. In summary, the time-sensitive experiment confirms the superior performance of steel cylinders in long-term gas storage. Their excellent sealing and chemical stability maintain the integrity of all components—including trace helium—over 30 days. In contrast, the permeability of aluminum-plastic airbags leads to severe loss of target components and significant air ingress, fundamentally altering sample composition. These findings underscore the importance of storage container selection based on intended storage duration and detection accuracy in helium-bearing natural gas studies. Table 2 Changes in gas content over time in dual-valve high-pressure steel cylinders and aluminum-plastic airbags in the time-sensitive experiment (a) Gas content of dual-valve high-pressure steel cylinder in the time-sensitive experiment Gas components Samples in steel cylinder Sample1 Sample2 Sample3 First test After 7 days After 15 days After 30 days First test After 7 days After 15 days After 30 days First test After 7 days After 15 days After 30 days CH4 /% 95.59 95.86 95.61 95.99 93.43 92.53 91.50 92.65 95.35 94.62 0.02 0.01 C2H6 /% 1.21 1.22 1.22 1.23 0.40 0.39 0.39 0.39 2.82 2.78 0.53 0.50 C3H8 /% 0.15 0.15 0.15 0.15 0.06 0.06 0.06 0.06 0.39 0.38 421.58 421.81 CO2 /% 1.68 1.65 1.66 1.67 7.12 6.96 6.99 7.13 1.19 1.17 186.96 187.28 O2 /% 0.01 0.01 0.01 0.01 0.00 0.00 0.01 0.01 0.01 0.01 94.81 93.88 N2 /% 0.96 1.00 0.97 0.98 0.12 0.10 0.12 0.12 0.53 0.50 2.78 2.77 He /ppm 661.22 622.87 621.48 582.09 234.19 226.94 214.25 200.37 493.50 431.00 0.38 0.38 H2 /ppm 119.53 114.55 119.61 116.94 0.00 0.00 0.00 0.00 183.11 184.89 1.21 1.17 (b) Gas content of aluminum-plastic airbag in the time-sensitive experiment Gas components Samples in aluminum-plastic airbag Sample1 Sample2 Sample3 First test After 7 days After 15 days After 30 days First test After 7 days After 15 days After 30 days First test After 7 days After 15 days After 30 days CH 4 /% 92.70 90.97 85.54 11.04 90.23 90.10 91.46 90.75 91.53 92.32 0.53 23.57 C 2 H 6 /% 1.17 1.14 1.09 0.21 0.38 0.38 0.38 0.37 2.65 2.67 1.87 41.71 C 3 H 8 /% 0.14 0.14 0.13 0.03 0.06 0.06 0.06 0.05 0.36 0.36 391.85 61.81 CO 2 /% 1.58 1.56 1.44 0.27 6.84 6.84 6.68 6.52 1.13 1.14 180.46 0.00 O 2 /% 0.31 1.03 2.39 19.59 0.17 0.17 0.33 0.65 0.41 0.42 92.76 18.90 N 2 /% 1.90 4.25 8.48 35.94 0.62 0.61 0.87 1.53 1.67 1.69 2.65 0.35 He /ppm 664.76 538.84 450.02 141.50 204.98 182.22 172.79 175.58 456.07 415.00 0.35 0.03 H 2 /ppm 113.00 103.62 93.71 0.00 0.00 0.00 0.00 0.00 184.33 182.93 1.11 0.11 3.2 Discussion Through the immediate comparative experiment and the time-sensitive experiment, the preservation performance of steel cylinders and aluminum-plastic airbags for helium-bearing natural gas samples was systematically evaluated. The results reveal significant differences in the preservation of gas components between the two containers, with these differences fundamentally originating from their material properties and structural designs. 3.2.1 Mechanism analysis of immediate differences The compositional differences observed in the immediate comparative experiment were primarily determined by the material properties of the two container types. The significantly elevated concentrations of N 2 and O 2 in the aluminum-plastic airbags indicate that air infiltration occurred even during the initial sampling stage. For example, the O 2 concentration in Sample 1 was 35.9 times that in the steel cylinder. This phenomenon can be attributed to structural limitations of the aluminum-plastic composite film. Although the aluminum foil layer serves as the primary barrier, molecular gaps in the polyethylene or polyamide plastic layers and micro-pores at the heat-sealed edges provide permeation pathways for small gas molecules. In contrast, the steel cylinders employ a 316 stainless steel monolithic structure and metal-face-sealed valves. The dense metallic crystal structure and high-precision machining achieve an nearly defect-free sealing effect, fundamentally preventing air infiltration. It is noteworthy that, despite the air permeation issue, the aluminum-plastic airbags maintained relatively good consistency with steel cylinders in the initial capture of helium and hydrocarbon gases, with an average relative deviation of 2.2%. This indicates that under strictly controlled immediate sampling conditions, aluminum-plastic airbags can meet short-term gas storage requirements. 3.2.2 Mechanism analysis of time-dependent differences The results of the time-dependent experiment showed that as the storage time increased, the performance difference between the two containers showed a significant widening trend. The severe loss of helium in aluminum-plastic airbags, such as the 30-day decay rate of 78.7% in Sample 1, can be explained by the physical properties and permeation behavior of helium. Helium molecules possess the smallest kinetic diameter and an extremely high diffusion coefficient, allowing them to easily penetrate microscopic defects and polymer chain gaps in the aluminum-plastic composite film. This permeation process follows Fick’s law of diffusion. The helium transmission rate may be positively correlated with the concentration difference across the membrane, the material’s permeability coefficient, and inversely related to membrane thickness. However, the barrier performance of the aluminum-plastic composite structure is inherently insufficient to contain helium due to its ultra-light characteristics. In addition to material permeability, the valves on aluminum-plastic airbags may develop sealing deficiencies with repeated use, potentially leading to further gas leakage and composition changes over time. In contrast, the steel cylinders demonstrated exceptional long-term stability, with a helium decay rate of only 12.0% over 30 days. This performance is attributed to the face-centered cubic (FCC) dense crystalline lattice structure of 316 stainless steel, which has an extremely low helium permeability coefficient, effectively inhibiting helium diffusion. In addition, the dual-valve design and metal-face-seal interface completely eliminate leakage risks, ensuring reliable long-term storage. 3.2.3 Error analysis This study implemented multiple measures to strictly control potential errors. ①All samples were taken from the same gas source at the same time to ensure initial compositional consistency. ②A standardized sampling procedure was used with precise control of purging cycles (4 times) and sampling pressure (2.0 ± 0.1 MPa). All experiments were performed by the same operator to minimize human-induced variations. ③The same Agilent 7890B gas chromatograph was used under consistent conditions to avoid instrumental systematic error, and the instrument was calibrated with standard reference gases before each sample set to ensure detection accuracy. ④Three replicate samples were used in each experimental group, and repeatability was evaluated using relative standard deviation (RSD < 2%). These measures effectively eliminated extraneous interfering factors, confirming that the storage container itself is the primary cause of the observed differences. Potential residual errors may include minor sample individuality, slight instrumental deviations (RSD < 2%), and subtle fluctuations in the storage environment. However, the magnitude of these errors is significantly smaller than the compositional changes resulting from container differences, and thus they do not substantially affect the overall conclusions. 4. Conclusion (1) Steel cylinders perform much better than aluminum-plastic airbags at preserving helium-bearing natural gas samples. Experiments showed that steel cylinders have a dense metal structure and high-quality seals. These features effectively prevent helium from leaking and block outside air from entering. Over 30 days, helium levels in steel cylinders decreased only slowly and steadily. The decay rate was between 12.0% and 14.4%. During this period, all other major gas components remained stable. These results confirm that steel cylinders are reliable for long-term storage and high-precision analysis. (2) Aluminum-plastic airbags can be used for short-term (< 7 days) storage under strictly controlled sampling conditions, but are not recommended for medium to long term storage of trace helium due to material permeation limitations. Although immediate comparative tests show acceptable initial capture performance, the composite film cannot effectively retain helium, which has a small molecular kinetic diameter of 0.26 nm. This leads to a gradual yet substantial loss of helium concentration, with decay rates reaching up to 78.7%. In addition, external air, such as N 2 and O 2 , may gradually infiltrate the bags, which can alter sample composition over time. Therefore, if such bags are used, it is essential to complete testing promptly after sampling to minimize composition changes and ensure result reliability. (3) The selection of storage containers is a critical factor affecting the accuracy of helium-bearing natural gas detection. Experimental results indicate that the permeability of the container material is the primary cause of data deviation, with its influence far exceeding secondary factors such as analytical instrument errors. Therefore, in helium resource exploration and evaluation, storage container performance must be a core consideration in quality control. Priority should be given to using high-airtightness steel cylinders to avoid misjudgment of resources due to inappropriate container selection. (4) It is essential to develop new types of storage containers and establish standardized sampling methods for trace gases. In light of the permeability limitations of aluminum-plastic airbags, future efforts should prioritize the development of composite materials with improved barrier properties. Researchers should also systematically examine how temperature and pressure affect helium retention. Furthermore, clear quantitative guidelines for container selection should be defined, taking into account gas composition, concentration, and expected storage time. These improvements will offer a scientific foundation for updating sampling protocols for helium-bearing natural gas and significantly increase the reliability and accuracy of trace helium detection. Declarations Data availability statement The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding author. Author Contributions Conceptualization, K.Y. and X.F.; methodology, K.Y. and X.X.; software, J.Y.; validation, J.Y., S.B. and K.Y.; formal analysis, K.Y.; investigation, K.Y.; resources, Y.X.; data curation, K.Y. and X.F; writing—original draft preparation, X.F.; writing—review and editing, X.F.; visualization, K.Y.; supervision, K.Y.; project administration, K.Y.; funding acquisition, K.Y. and X.F.. All authors have read and agreed to the published version of the manuscript. Funding The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. China Geological Survey Geological Survey Special Project "National Survey of Helium Resources" (no. DD20240201203) and "Assessment of Oil and Potash Combined Exploration Resources in the Huangshi Area of the Western Qaidam Basin" (no. DD20230203611), Academy of Geological Sciences Basal Research Fund "Sequence stratigraphic configuration, spatiotemporal differences, and controlling factors of the Upper Carboniferous mixed layer system in the Ounan Depression of the eastern Qaidam Basin" (no. JKYQN202410). Acknowledgments We would like to express our gratitude to Shunshuang Jin, Chao Wang, Degang Mu, Xianglong Meng and Tuo Lin from Oil and Gas Resources Survey, China Geological Survey for their valuable support and inspiration provided throughout the writing process. Consent to Participate declaration Not applicable Ethics and Consent to Publish declarations Not applicable. Conflicts of Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Publisher’s note All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher. References Tao Shizhen C, Yue Y. Classification system of helium resources and zones in China, effectiveness and enrichment mode of controlling factors [J]. Nat Gas Earth Sci. 2024;35(05):869–89. Qin Shengfei D, Lirong T, Gang, et al. Helium Enrichment Theory and Exploration Ideas for Rich Helium Resources [J]. Pet Explor Dev. 2024;51(05):1160–74. Tao Shizhen Y, Yiqing C, Yue, et al. Geological conditions, genesis mechanisms, and enrichment laws of helium gas resources [J]. Pet Explor Dev. 2024;51(02):436–52. Tao Xiaowan L, Jianzhong Z, Libin, et al. The current status of helium resources in China and the discovery of the first super large helium rich reserve: Hetianhe gas field [J]. Earth Sci. 2019;44(03):1024–41. Qin Shengfei L, Jiyuan W. Helium Enrichment Model of Rich Helium Natural Gas Reservoirs in Oil and Gas Basins in China [J]. Nat Gas Ind. 2022;42(07):125–34. Chao Haide C, Jianzhou W. Discovery and Enrichment Mechanism of Water Soluble Helium Resources in Chaidamu Basin [J]. Northwest Geol. 2022;55(04):61–73. 10.19751/j.cnki. 61-1149/p.2022.04.005 . Liu Chenglin W, Xinpei C, Changbo, et al. Development prospects of unconventional oil and gas and renewable energy in China [J]. World Petroleum Ind. 2025;32(03):12–21. Zhang Xue L, Chenglin F, Liyong, et al. Geochemical characteristics and enrichment models of helium-bearing natural gas in Sulige gas field, Ordos Basin [J]. Natural Gas Geosciences; 2025. Song H, Liwu L, Qingyan T, et al. Research progress and significance of common rare gas sampling containers [J]. Geol Sci. 2022;57(01):274–93. Yang Chuanli M, Jun W, Kai, et al. Analysis of the Influence of Gas Sampling Containers on Carbon Isotope Values of Hydrocarbons [J]. Low Permeability Oil and Gas Fields; 2012. pp. 125–8. 1. Zhang Fuyuan Z, Yana YM. Analysis of Natural Gas Composition and Uncertainty in Physical Property Parameter Calculation [J]. Petroleum Nat Gas Chem Ind, 2006 (01): 65–9. Li C, Ji Q, Yongjie C et al. The Influence of Normalization on Uncertainty in Natural Gas Composition Analysis [J]. Petroleum Ind Tech Supervision 2 016, 32 (03): 35–8. Tang Meng L, Qin CY. Research and Application of Natural Gas Analysis and Testing Technology [J]. Petroleum and Natural Gas Chemical Industry, 2008 (S1): 42–52. Zou Yi L, Qingyong C, Jianfa et al. Physical simulation experiment study on competitive dissolution of helium gas in helium rich reservoirs [J]. Coalf Geol Exploration 2 025, 53 (06): 96–108. Wang Dongliang M, Chenghua L. The influence of sampling devices on the detection results of carbon isotopes in natural gas [J]. Nat Gas Earth Sci. 2010;21(02):345–9. Xing Lantian L, Zhongping Z. The influence of different sampling devices and storage times on the carbon, hydrogen, and oxygen isotopes of non hydrocarbon gases [J]. Nat Gas Earth Sci. 2020;31(04):483–7. Zeng Wenping H, Liming L, Qin, et al. Development Status and Prospects of Natural Gas Analysis and Detection Technology in China [J]. Petroleum Nat Gas Chem Ind. 2013;42(01):68–73. Li Cheng Z. Determination of Non-methane Hydrocarbons in Ambient Air by Canister Sampling-Transfer Bag Injection-Gas Chromatography [J]. Arid Environ Monit. 2024;38(1). 10.3969/ j.issn.1007-1504.2024.01.002. George V. Chilingarian,Teh Fu Yen. Petroleum geochemistry and geology [J]. Sed Geol. 1980. 10.1016/0037-0738(80)90018-4 Li Cheng S. Zhuang. Comparison Study of Non Methane Total Hydrocarbons Determined by Different Sampling and Storage Methods [J]. Environ Sci Technol. 2016, (0s2).335–8. Kong Lingchang Research on Field Gas Samplers and Sampling Methods. [J] Seismic Geol, 1992, (03):286–8. Zeng Wenping M, Jian. Chang Honggang Discussion on the Analysis and Comparison of Natural Gas Composition [J]. Petroleum Ind Tech Superv ,2 008 (08): 9–11. Najman J, Sliwka I. The Cryogenic Enrichment System in Chromatographic Analysis of Noble Gases in Groundwater[J]. Acta Physica Polonica, A. General Physics, Physics of Condensed Matter, Optics and Quantum Electronics, Atomic and Molecular Physics, Applied Physics,2016,130(3):737–742. 10.12693/APhysPolA.130.737.3 Chen Gengliang. On the Traceability of Natural Gas Composition Analysis [J]. Petroleum Nat Gas Chem Ind, 2008 (03): 243–8. Tang Meng C, Yongjie. Conventional analysis methods and standardization of natural gas composition [J]. Petroleum and Natural Gas Chemical Industry; 2002. pp. 64–70. S1. Tao Cheng L, Wenhui Y, Huamin, et al. Joint measurement technology and application of rare gas concentration and isotope ratio in natural gas [J]. J Mass Spectrom. 2018;39(02):201–8. Chen Gengliang. Analysis methods and instruments for natural gas quality indicators [J]. Urban Gas, 2003 (08): 3–6. Zhang J. Preservation of gas samples and changes in their composition [J]. Monit arid Environ, 1995, (03):172–80. Zou Wei. Analysis of Common Methods for Natural Gas Sampling and Their Impact on Analysis Results [J]. J Metrol Sci Technol. 2021;65(07):65–8. Xu Quanmin Z, Zhijing H, Xiaobo et al. Analysis of the influencing factors of environmental air sample collection [J]. Chem Res Application 2 010, 22 (12): 1605–6. Li Wei B, Chengzhi. Environ Dev. 2019;31(03):97–8. 10.16647/j.cnki. cn15-1369/X.2019.03.056 . Zhou Yongjun Application of Fluoropolymer Gas Bags in the Determination of Non Methane Total Hydrocarbons [J]. Yao Cheng. Research on the collection of volatile organic compounds from fixed pollution sources using airbag method [J]. Environ Dev. 2017;29(08):122–3. Oda J-I, Hayashi Y, Asada Y. et.al. Simultaneous Determination of Inorganic Nitrogen Species in Seawater by Ion Chromatography Utilization of Gas-diffusion/o-Phthalaldehyde Method for Fluorometric Determination of Ammonium Ion [J].Bunseki Kagaku. 2019, 68(3):189–93. 10.2116/bunsekikagaku.68.189 Wenping Z, Qin L. Analysis of Differences and Similarities in Natural Gas Quality Detection Methods between Domestic and Foreign Standards [J]. Petroleum Nat Gas Chem Ind. 2015;44(03):104–8. Fan Liyong W, Jianshe H, Aiping. The geochemical characteristics, genesis sources, and main controlling factors of helium-bearing natural gas in Sulige gas field, Ordos Basin [J]. Nat Gas Geosci. 2025;36(3):399–412. 10.11764/j.issn. 1672-1926.2024.10.012 . Yu Z, Liyong F, Junfeng R. The Cambrian Ordovician natural gas reservoir formation model and favorable exploration areas in the Ordos Basin [J]. Nat Gas Ind. 2024;44(8):44–57. 10.3787/j.issn.1000-0976.2024.004 . Hou Fanghao F, Shaoxian D, Zhaoxiong. Sedimentary Environment and Lithofacies Development Characteristics of the Majiagou Formation in the Middle Ordovician of the Ordos Basin [J]. J Sedimentology. 2003;21(1):106–12. 10.3969/j.issn.1000-0550.2003.01.016 . Tao L, Songyu M, Xiaohui L. The Sandbody Stacking Model and Oil and Gas Development Significance of Permian Shanxi Formation in Daniudi Gas Field, Ordos Basin [J]. Lithological Oil Gas Reservoirs. 2024;36(2):147–59. 10.12108/yxyqc.20240214 . He Faqi W, Fubin W, Jie. The distribution pattern of helium gas in Dongsheng gas field in Ordos Basin and the discovery of a super large helium rich gas field [J]. Petroleum Experimental Geol. 2022;44(1):1–10. 10.11781/sysydz202201001 . Ma Yong C, Jianfa X, Zhiyuan. Potential and Enrichment Mechanism of Helium Resources in Unconventional Natural Gas [J]. Acta Petroleum Sinica. 2025;46(2):440–455482. 10.7623/syxb202502011 . Chen Jianfa F, Rao. Characteristics and main controlling factors of helium rich natural gas reservoirs [J]. Acta Petroleum Sinica. 2022;43(11):1652–63. 10.7623/syxb202211012 . Liu Chenglin Z, Yaxiong W, Xinpei. Comparison and Implications of Helium Geological Conditions and Resource Potential between China and the United States [J]. World Petroleum Ind. 2024;31(2):1–10. 10.20114/j.issn.1006-0030.202307001 . General Administration of Quality Supervision. Inspection and Quarantine of the People's Republic of China Composition analysis of natural gas by gas chromatography: GB 13610 – 2020 [S]. Beijing: China Standard; 2020. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 29 Mar, 2026 Read the published version in Discover Sustainability → Version 1 posted Editorial decision: Revision requested 19 Jan, 2026 Reviews received at journal 12 Jan, 2026 Reviewers agreed at journal 30 Dec, 2025 Reviews received at journal 09 Dec, 2025 Reviewers agreed at journal 30 Nov, 2025 Reviewers agreed at journal 18 Nov, 2025 Reviews received at journal 10 Oct, 2025 Reviewers agreed at journal 14 Sep, 2025 Reviewers invited by journal 14 Sep, 2025 Editor assigned by journal 09 Sep, 2025 Submission checks completed at journal 09 Sep, 2025 First submitted to journal 03 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7524670","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":516037366,"identity":"82bf22fc-1ca4-4d63-91a4-48f8d147db99","order_by":0,"name":"Xinxin Fang","email":"","orcid":"","institution":"Institute of Geomechanics, Chinese Academy of Geological Sciences","correspondingAuthor":false,"prefix":"","firstName":"Xinxin","middleName":"","lastName":"Fang","suffix":""},{"id":516037367,"identity":"a49cf252-dfef-439b-9eb9-5371e28788db","order_by":1,"name":"Kun Yuan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYBACCVRuBQMPqVrOkKyFsY2gBgYGyRm5x6R5au7Iyfsffvzy57w6GXP2A4wfPubg1iItkZcmzXPsmbHhjTQza95th3ksexKYJWduw61FTiLHTJqH7XDixhk8bMaM2w7wGBxIYGPmJajlH1BL/xk2w59z6ngMzj/Ar0UapIW37XDifIYc5ge8Dcw8BjcI2CLZ88bYcm7fYWMDiTQzZp5jh4FaHjbj9YvE8RzDG2++HZaT7z/8+OOPmjp7g/PJBz98xKMFCFjAcWNwgIENGkmMDXjVAwHzBxAp3wBljIJRMApGwShABwCOG04QXIpklwAAAABJRU5ErkJggg==","orcid":"","institution":"Oil and Gas Resources Survey, China Geological Survey","correspondingAuthor":true,"prefix":"","firstName":"Kun","middleName":"","lastName":"Yuan","suffix":""},{"id":516037368,"identity":"555649df-b23a-4a23-8306-052fe64f8164","order_by":2,"name":"Xuemin Xu","email":"","orcid":"","institution":"National Research Center for Geoanalysis","correspondingAuthor":false,"prefix":"","firstName":"Xuemin","middleName":"","lastName":"Xu","suffix":""},{"id":516037369,"identity":"f3c6bae3-fa2e-4788-b851-484689d8b12f","order_by":3,"name":"Jiajia Yang","email":"","orcid":"","institution":"National Research Center for Geoanalysis","correspondingAuthor":false,"prefix":"","firstName":"Jiajia","middleName":"","lastName":"Yang","suffix":""},{"id":516037370,"identity":"8b99f1b9-39c3-429e-9b2a-1b8f72eb183f","order_by":4,"name":"Yinbo Xu","email":"","orcid":"","institution":"Oil and Gas Resources Survey, China Geological Survey","correspondingAuthor":false,"prefix":"","firstName":"Yinbo","middleName":"","lastName":"Xu","suffix":""},{"id":516037371,"identity":"3796321d-a8f0-4d5d-990a-c6cea9111ca5","order_by":5,"name":"Shujing Bao","email":"","orcid":"","institution":"Oil and Gas Resources Survey, China Geological Survey","correspondingAuthor":false,"prefix":"","firstName":"Shujing","middleName":"","lastName":"Bao","suffix":""}],"badges":[],"createdAt":"2025-09-03 08:38:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7524670/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7524670/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s43621-026-03047-6","type":"published","date":"2026-03-29T16:10:35+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":91889677,"identity":"40fc44e5-d8e7-4910-a1f1-04c5f0024664","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":309022,"visible":true,"origin":"","legend":"","description":"","filename":"VVV3.1ImpactofSamplingContainersontheAnalyticalResultsofHeliumBearingNaturalGas1.docx","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/475b9d0aaf117a8df2ca17b5.docx"},{"id":91889678,"identity":"c8fe7203-37e0-4880-8656-37702693806e","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":9167,"visible":true,"origin":"","legend":"","description":"","filename":"34077d7439024037b3faacb3867b8f21.json","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/60a009a2b1c6ba2a689ec525.json"},{"id":91890067,"identity":"aedeea65-d7ca-407e-af00-d9be981b4db2","added_by":"auto","created_at":"2025-09-22 16:04:10","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":146310,"visible":true,"origin":"","legend":"","description":"","filename":"34077d7439024037b3faacb3867b8f211enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/9fc85a3efdccf1ed3c93fc4d.xml"},{"id":91890068,"identity":"8e5ab514-7e15-4782-8a09-52555eb3f95c","added_by":"auto","created_at":"2025-09-22 16:04:10","extension":"jpeg","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":125486,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/8baece2bdfaed20fb2a439f2.jpeg"},{"id":91890069,"identity":"f6acd734-02d0-47ed-a231-d51c7599762b","added_by":"auto","created_at":"2025-09-22 16:04:10","extension":"wmf","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":317544,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.wmf","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/6ecb014da641876c616d1fc4.wmf"},{"id":91889683,"identity":"83b06fdc-99f2-46d7-b6ae-831223a99e6c","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"wmf","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":462216,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.wmf","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/048dd91765ef693231da5f88.wmf"},{"id":91889679,"identity":"c4518a91-4919-408f-adb8-a2b0792b765c","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"wmf","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":317544,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.wmf","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/63431de95e581d94f9d87353.wmf"},{"id":91891571,"identity":"8cd2e3f4-90da-4226-92a6-038dbb6f19a5","added_by":"auto","created_at":"2025-09-22 16:12:10","extension":"wmf","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":462216,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.wmf","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/bc02f6b78d1d80ae2569921d.wmf"},{"id":91889681,"identity":"df17424f-c7d9-40bc-955d-011a2a61fe25","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":27762,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/ace7a016ca2c4607bac2fb9e.png"},{"id":91889686,"identity":"3e8ad5d5-81b6-42f9-b51a-77719bf70969","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":100307,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/341b27b2bea52f1e91b8b51e.png"},{"id":91889689,"identity":"2e969715-f814-417a-86ec-5f5059b1b962","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":74875,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/f2f59ea9a0d455a30754fd30.png"},{"id":91889692,"identity":"ce80da20-592e-4b94-b3e9-5670d8d32465","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":100307,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/fb4269b5a9ef4444de798587.png"},{"id":91891572,"identity":"e8244749-c287-45a7-938f-dc1e197a04f2","added_by":"auto","created_at":"2025-09-22 16:12:10","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":74875,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/4c038313a6399bcd30edee6b.png"},{"id":91890072,"identity":"60e4000e-1ba0-4ffb-b16f-ea0a9e7e2fdb","added_by":"auto","created_at":"2025-09-22 16:04:10","extension":"xml","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":142571,"visible":true,"origin":"","legend":"","description":"","filename":"34077d7439024037b3faacb3867b8f211structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/cc4acbe528c6a8e658a18d75.xml"},{"id":91889690,"identity":"a1e2b7a1-55d6-4b40-8a27-97ddd9243964","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"html","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":151130,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/bf194c27c6829163e9a2e3ab.html"},{"id":91890066,"identity":"1d8ef912-3e42-4ac8-a5ed-815fee0281b6","added_by":"auto","created_at":"2025-09-22 16:04:10","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":125486,"visible":true,"origin":"","legend":"\u003cp\u003eSampling process of dual-valve high-pressure steel cylinder and aluminum-plastic airbag\u003c/p\u003e","description":"","filename":"image1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/2449e3d66275b75979342070.jpeg"},{"id":91889674,"identity":"e8f39725-7dd9-445f-9c85-21d557b86558","added_by":"auto","created_at":"2025-09-22 15:56:10","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":16212,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of gas content between dual-valve high-pressure steel cylinder and aluminum-plastic airbag\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/f72bd14249d70094a74564ff.png"},{"id":91891570,"identity":"7bfe824e-630c-4311-94b0-52cbbe8917ad","added_by":"auto","created_at":"2025-09-22 16:12:10","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":41303,"visible":true,"origin":"","legend":"\u003cp\u003eChanges in gas content over time in dual-valve high-pressure steel cylinders and aluminum-plastic airbags\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/e896561a591bec5aec673c48.png"},{"id":105755245,"identity":"7b7b8250-3c97-45af-9b27-508d3184ca0c","added_by":"auto","created_at":"2026-03-30 16:26:22","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1340793,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7524670/v1/2f21de86-9b4f-46cf-bbfa-e753c558b019.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of Sampling Containers on the Analytical Results of Helium-Bearing Natural Gas","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eHelium is a key strategic rare gas vital to national security and the development of high-tech industries. Owing to its unique physical and chemical properties\u0026mdash;such as low boiling point, high thermal conductivity, and strong chemical inertness\u0026mdash;it is irreplaceable in cutting-edge fields including deep space exploration, low-temperature superconductivity, large-scale scientific facilities, semiconductor manufacturing, and high-end medical equipment [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe global distribution of helium resources is highly uneven. China has long relied heavily on imports, with an external dependency rate exceeding 90%. Although significant helium-rich natural gas reservoirs have recently been discovered in basins such as Ordos and Tarim, along with water-soluble helium resources in the Qaidam and Weihe Basins [\u003cspan additionalcitationids=\"CR4 CR5 CR6 CR7\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], the accurate development and utilization of these resources rely heavily on highly reliable detection data. In fact, the entire process of helium resource exploration and evaluation depends critically on the precision of such data.\u003c/p\u003e\u003cp\u003eHelium possesses distinct molecular characteristics. These include the smallest molecular diameter (only 0.26 nm), a high diffusion coefficient in gases, and trace concentrations in natural gas, typically below 1%. These properties make it highly susceptible to loss and contamination throughout sampling, storage, and detection. Such challenges are far more pronounced than those associated with conventional hydrocarbon components. As a result, stringent quality control across the entire detection process is essential [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAmong the numerous factors influencing the accuracy of trace helium detection, the choice of sampling containers is regarded as one of the key potential sources of error [\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Currently, different researchers have carried out a series of studies on gas sampling containers. Dual-valve high-pressure steel cylinders are widely considered the preferred vessels for high-precision gas sampling due to their extremely low permeability (\u0026lt;\u0026thinsp;0.001%/year) and superior sealing performance [\u003cspan additionalcitationids=\"CR15 CR16\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. On the other hand, although aluminum-plastic airbags offer advantages such as light weight and low cost, their material may lack sufficient barrier properties against light gases like He and H\u003csub\u003e2\u003c/sub\u003e. This can easily lead to distortion of sample composition through adsorption, permeation, and other effects, thereby introducing considerable deviations in detection results [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWhile existing studies have addressed performance differences among storage containers, most have focused on common gases or high-concentration components [\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. There remains a lack of systematic comparative research on the short- and medium-term stability of trace helium in commercially used containers such as steel cylinders and aluminum-plastic airbags. Furthermore, empirical data under real helium-bearing natural gas conditions are insufficient. In addition, most current natural gas analysis standards are designed for hydrocarbons and high-concentration non-hydrocarbon components, making them poorly suited to the trace characteristics of helium. As a result, there is no clear and reliable regulatory guideline for selecting storage containers in helium-bearing natural gas detection [\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eTo clarify how storage containers affect the test results of helium-bearing natural gas, this study designed and carried out two sets of comparative experiments. These experiments systematically evaluate the ability of dual-valve high-pressure steel cylinders (hereinafter referred to as steel cylinders) and aluminum-plast airbags to maintain sample integrity, and their impact on detection reliability throughout the sampling, storage, and transportation processes.\u003c/p\u003e\u003cp\u003eThe first experiment is an immediate comparative experiment. Both steel cylinders and aluminum-plastic airbags were used to collect parallel samples from the same gas source. These samples were analyzed immediately to compare differences in the initial test results. The second experiment is a time-sensitive experiment. Samples stored in both types of containers were analyzed after different storage periods. This was done to evaluate the preservation performance of each container type and to observe changes in helium concentration over time.\u003c/p\u003e\u003cp\u003eThe ultimate goal of this study is to provide essential data support and a theoretical basis for improving the accuracy of helium-bearing natural gas resource evaluation and for refining related detection standards.\u003c/p\u003e"},{"header":"2 Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Experimental Materials and Equipment\u003c/h2\u003e\u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\u003ch2\u003e2.1.1 Sampling containers\u003c/h2\u003e\u003cp\u003eIn this study, dual-valve high-pressure steel cylinders and aluminum-plastic airbags were selected as comparative storage container. Both are widely used gas sampling containers in industrial and scientific research fields [\u003cspan additionalcitationids=\"CR27\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], but there are significant differences in their material, structure, and physicochemical properties, which is also the fundamental reason for the differences in their gas preservation performance.\u003c/p\u003e\u003cp\u003e(1) Dual-valve high-pressure steel cylinders\u003c/p\u003e\u003cp\u003eThe steel cylinders used in this experiment are made of 316 stainless steel and have a nominal volume of 2L. This material offers excellent chemical inertness and corrosion resistance, effectively preventing reactions with trace corrosive components (e.g., H\u003csub\u003e2\u003c/sub\u003eS, CO\u003csub\u003e2\u003c/sub\u003e) in helium-bearing natural gas and helping maintain the chemical integrity of the samples.\u003c/p\u003e\u003cp\u003eThe inner walls of the cylinders have been mechanically polished and passivated, significantly reducing surface adsorption of gas molecules (especially trace components). A key feature is the dual-valve design with metal-face seals, which allows rapid gas filling and discharging while ensuring high sealing integrity and an extremely low leakage rate.\u003c/p\u003e\u003cp\u003eOwing to its high pressure resistance (with a working pressure up to 20 MPa) and extremely high density of 316 stainless steel, the cylinders are nearly impermeable to small gas molecules such as helium. These properties make them the preferred container for high-precision gas sampling and long-term storage [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e(2) Dual-valve aluminum-plastic airbags\u003c/p\u003e\u003cp\u003eThe aluminum-plastic airbag is made of multiple layers of composite film, with a typical structure of an outer layer (nylon film), a barrier layer (aluminum foil), and an inner layer (polyethylene PE). The airbags used in this experiment have a nominal volume of 500 mL, with the aluminum foil barrier layer having a thickness of approximately 12 \u0026micro;m. A sealed chamber is formed through a thermal fusion process, and two one-way plastic valve nozzles are equipped for gas filling and venting.\u003c/p\u003e\u003cp\u003eThe aluminum foil layer acts as the primary barrier structure, which can partially inhibit the rapid permeation of light gases such as helium. However, its barrier performance is considerably lower than that of steel cylinders [\u003cspan additionalcitationids=\"CR32\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Although this type of airbag offers advantages such as good flexibility and light weight, it has poor mechanical strength and pressure resistance, making it susceptible to damage or leakage from punctures and compression. Furthermore, during long-term storage, the polymer materials are prone to aging. If the aluminum foil layer is damaged, it will further exacerbate the slow leakage of gases (especially helium) through microscopic defects. Therefore, it is often used for temporary gas sampling and storage with low precision requirements and short cycles [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section3\"\u003e\u003ch2\u003e2.1.2 Gas source\u003c/h2\u003e\u003cp\u003eThe gas used in this experiment was sourced from a natural gas field located in the eastern Ordos Basin, China. The primary gas-producing intervals in this field are the Middle Ordovician Majiagou Formation and the Permian Shanxi Formation [\u003cspan additionalcitationids=\"CR36 CR37\" citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e], which form a proven helium-bearing natural gas reservoir.\u003c/p\u003e\u003cp\u003eThe background helium content of the natural gas samples ranges from 200 ppm to 1000 ppm [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. This concentration range is representative of the typical trace helium levels found in most helium-bearing natural gas reservoirs in China [\u003cspan additionalcitationids=\"CR41\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e], making the experimental conclusions of this study representative. In addition to helium, the main component of this natural gas is methane (CH\u003csub\u003e4\u003c/sub\u003e), which also contains a certain amount of heavy hydrocarbons such as nitrogen (N\u003csub\u003e2\u003c/sub\u003e) and ethane (C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e), as well as trace amounts of non hydrocarbon components.\u003c/p\u003e\u003cp\u003eThis gas source was selected due to its stable and well-characterized helium content, which provides a reliable basis for comparing the preservation behavior of trace helium across different storage containers. All comparative experiments were performed using natural gas samples collected from the same gas source and in the same batch to ensure experimental consistency and minimize the impact of source variability on the results.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\u003ch2\u003e2.1.3 Analytical Instruments\u003c/h2\u003e\u003cp\u003eQualitative and quantitative analysis of the components in helium-bearing natural gas was conducted at the National Research Center for Geoanalysis. The core analytical instrument used was an Agilent 7890B gas chromatograph, equipped with one hydrogen flame ionization detector (FID) and two thermal conductivity detectors (TCD). The FID was employed for high-sensitivity detection of C\u003csub\u003e1\u003c/sub\u003e\u0026thinsp;~\u0026thinsp;C\u003csub\u003e5\u003c/sub\u003e hydrocarbon gases. One of the TCD detectors was specifically optimized for quantitative analysis of permanent gases\u0026mdash;including He, H\u003csub\u003e2\u003c/sub\u003e, N\u003csub\u003e2\u003c/sub\u003e and O\u003csub\u003e2\u003c/sub\u003e\u0026mdash;due to its high response to helium. This detector configuration enables simultaneous and accurate analysis of both trace helium and conventional gas components.\u003c/p\u003e\u003cp\u003eThe analytical procedure strictly adhered to the Chinese national standard GB/T 13610\u0026thinsp;\u0026minus;\u0026thinsp;2020 (Natural Gas Analysis by Gas Chromatography). To achieve precise detection of trace helium and avoid interference from component co-elution, key parameters were optimized as follows:\u003c/p\u003e\u003cp\u003e(1) The injection port was operated in split mode (split ratio 5:1) at 250℃ to balance detection sensitivity and column load.\u003c/p\u003e\u003cp\u003e(2) A parallel dual-column configuration was used, consisting of a 3-ft HayeSep Q column and an 8-ft 5\u0026Aring; molecular sieve column.\u003c/p\u003e\u003cp\u003e(3) The temperature program was set as: hold at 60 ℃ for 1 min \u0026rarr; ramp to 80℃ at 20℃/min \u0026rarr; ramp to 190 ℃ at 30 ℃/min and hold for 2 min.\u003c/p\u003e\u003cp\u003eThis method ensured baseline separation of He from H\u003csub\u003e2\u003c/sub\u003e, N\u003csub\u003e2\u003c/sub\u003e and other components (separation factor\u0026thinsp;\u0026gt;\u0026thinsp;1.5). The instrument\u0026rsquo;s limit of detection (LOD) for He was below 5 ppm, and the analytical accuracy, expressed as relative standard deviation (RSD), was better than \u0026plusmn;\u0026thinsp;2%.\u003c/p\u003e\u003cp\u003eQuantitative analysis was performed using an external standard method. A calibration curve was constructed using a mixture of standard gases with three or more concentration levels covering He, CH\u003csub\u003e4\u003c/sub\u003e, H\u003csub\u003e2\u003c/sub\u003e and CO\u003csub\u003e2\u003c/sub\u003e (He concentration range: 0.003\u0026ndash;10%). The correlation coefficient (\u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e) exceeded 0.9995. A sample volume of 450 \u0026micro;L was injected, enabling simultaneous quantification of C\u003csub\u003e1\u003c/sub\u003e\u0026thinsp;~\u0026thinsp;C\u003csub\u003e5\u003c/sub\u003e, C\u003csub\u003e6\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e hydrocarbons, and non-hydrocarbon components including He, H\u003csub\u003e2\u003c/sub\u003e, CO\u003csub\u003e2\u003c/sub\u003e, CO, N\u003csub\u003e2\u003c/sub\u003e and O\u003csub\u003e2\u003c/sub\u003e. The quantification limit for He was 0.01% (mol/mol).\u003c/p\u003e\u003cp\u003eFor quality control, every batch of 10 samples included one duplicate and one standard gas sample. The relative deviation of component response values in the standard gas was required to be \u0026le;\u0026thinsp;1%. All replicate measurements complied with the precision criteria specified in GB/T 13610\u0026thinsp;\u0026minus;\u0026thinsp;2020 [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e2.2. Experimental Methods\u003c/h2\u003e\u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\u003ch2\u003e2.2.1 Sampling process\u003c/h2\u003e\u003cp\u003eTo ensure high comparability among samples originating from the same gas source and minimize the introduction of extraneous variables during sampling, this study followed a strict standardized sampling protocol. Sampling was performed at the pressure gauge interface downstream of the wellhead separator (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) to guarantee sample representativeness. The standardized procedure is described as follows:\u003c/p\u003e\u003cp\u003e(1) System purging and preparation\u003c/p\u003e\u003cp\u003eThe gas source valve was closed and the vent valve opened to release residual gas from the pipeline. After removing the pressure gauge, the gas source valve was slowly reopened, allowing high-velocity gas flow to flush the interface for 10\u0026thinsp;~\u0026thinsp;15 seconds to eliminate impurities and residual air.\u003c/p\u003e\u003cp\u003e(2) Connection and leak testing\u003c/p\u003e\u003cp\u003eOne end of the sampling line was connected to the purged sampling port, and the other end was sealed to the inlet valve of the sampling container (either a dual-valve high-pressure steel cylinder or an aluminum-plastic airbag). After connection, a leak test was performed to ensure all interfaces were airtight.\u003c/p\u003e\u003cp\u003e(3) Container and Line Purging (Replacement)\u003c/p\u003e\u003cp\u003eThis step is critical for ensuring sample purity. The inlet valve of the sampling container was opened, followed by slowly opening the gas source valve. ①For dual-valve steel cylinders: the outlet valve was opened to vent gas from the container and line until zero pressure was reached for 10\u0026thinsp;~\u0026thinsp;15 seconds, after which the outlet valve was closed. This process was repeated four times. ②For aluminum-plastic airbags: purging was achieved through repeated inflation and deflation. The bag was filled with gas, then squeezed to expel the gas. This cycle was repeated four times.\u003c/p\u003e\u003cp\u003e(4) Sample Filling\u003c/p\u003e\u003cp\u003eAfter completing the required number of purging cycles, sample filling was conducted under stable gas source pressure. ①For steel cylinders: the outlet valve was closed, and the cylinder was filled until pressure stabilized at the target value. The inlet valve was then closed. ②For aluminum-plastic airbags: inflation continued until the bag reached its nominal volume. The gas source valve was then closed, and the connection promptly disconnected.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e(5) Final Step\u003c/p\u003e\u003cp\u003eThe gas source valve was closed, and the sampling line was depressurized. After disconnecting the sampling container, it was immediately labeled with key information such as sampling time and gas source number.\u003c/p\u003e\u003cp\u003eThroughout the sampling process, all samples were collected from the same port using the same sampling line under consistent gas source pressure. The number of purging cycles was strictly maintained at four for all samples. These measures minimized systematic errors during sampling, ensuring that any observed differences in gas composition could be primarily attributed to the properties of the storage containers themselves.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\u003ch2\u003e2.2.2 Experimental design\u003c/h2\u003e\u003cp\u003eTo systematically evaluate the impact of storage containers on the test results of helium-bearing natural gas, this study designed two sets of comparative experiments. All experiments were conducted under constant temperature (25\u0026thinsp;\u0026plusmn;\u0026thinsp;1℃) and humidity (relative humidity 50\u0026thinsp;\u0026plusmn;\u0026thinsp;5%) laboratory conditions to eliminate interference from environmental factors.\u003c/p\u003e\u003cp\u003e(1) Experiment 1: Immediate Comparative Experiment\u003c/p\u003e\u003cp\u003eThis experiment aimed to determine whether different storage containers introduce immediate systematic deviations in initial helium detection results under strictly standardized sampling procedures, thereby evaluating the inherent reliability of each container type during sampling.\u003c/p\u003e\u003cp\u003eSamples were collected simultaneously from the same gas source, at the same sampling point, and at the same time. Parallel sampling was performed using dual-valve high-pressure steel cylinders and aluminum-plastic airbags, each subjected to four standardized \u0026ldquo;filling-evacuation\u0026rdquo; replacement cycles. A total of nine natural gas samples from different drilling wells were collected to improve statistical significance.\u003c/p\u003e\u003cp\u003eControlled variables included sampling pressure (2.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1MPa), connecting pipelines, purge cycles, and operating personnel. All sealed samples were transported to the same laboratory within 10 days and analyzed using an Agilent 7890B gas chromatograph. The initial test results from the two container types were directly compared, with particular emphasis on differences in helium content.\u003c/p\u003e\u003cp\u003e(2) Experiment 2: Time-Sensitive Experiment\u003c/p\u003e\u003cp\u003eThis experiment aimed to investigate the sample preservation capabilities of steel cylinders and aluminum-plastic airbags over different storage periods, with a focus on the decay behavior of trace helium concentration and the medium- to long-term preservation performance of each container.\u003c/p\u003e\u003cp\u003eSamples were obtained from three drilling gas sources with varying helium background concentrations (approximately 0.02%, 0.04%, and 0.06%, mol/mol). From each source, multiple parallel sample sets (steel cylinder group and airbag group) were synchronously prepared using the standardized sampling procedure, with three replicates per group to assess repeatability and error.\u003c/p\u003e\u003cp\u003eAll filled and sealed samples were stored under identical protected conditions. Subsets of samples were retrieved and analyzed at predetermined intervals: immediately upon delivery, and after 7, 15, and 30 days of storage.\u003c/p\u003e\u003cp\u003eThe helium concentration was measured at each time point, and the decay rate was calculated as: Decay Rate (%) = [(Initial Concentration \u0026ndash; Concentration at Day T) / Initial Concentration] \u0026times; 100, Concentration-time curves and decay rate charts were generated to systematically analyze helium loss trends in each container type.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"3. Results and Discussion","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Results\u003c/h2\u003e\u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\u003ch2\u003e3.1.1 Results of the immediate comparative experiment\u003c/h2\u003e\u003cp\u003eThe immediate comparative experiment evaluated the initial capture reliability of two storage containers for various components of helium-bearing natural gas by systematically analyzing parallel-collected samples from the same gas source. The results indicate that although both containers show good consistency for major target components, significant differences exist in the permeation of air components.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e(1) Consistency of hydrocarbon gas components\u003c/p\u003e\u003cp\u003eConcentrations of hydrocarbon gases\u0026mdash;such as CH\u003csub\u003e4\u003c/sub\u003e, C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e, C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e8\u003c/sub\u003e\u0026mdash;were highly similar in both steel cylinders and aluminum-plastic airbags (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(a-c)), with slightly higher values consistently observed in the steel cylinders.\u003c/p\u003e\u003cp\u003eSpecifically, the average CH\u003csub\u003e4\u003c/sub\u003e concentration across the nine samples was 94.08%\u0026plusmn;2.41% in the steel cylinder group and 91.99%\u0026plusmn;2.51% in the airbag group, yielding an average relative deviation of 2.2%. The largest discrepancy was observed in Sample 4, with values of 96.63% (cylinder) and 94.90% (airbag), representing an absolute difference of 1.73%.\u003c/p\u003e\u003cp\u003eC\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e exhibited even stronger consistency: both containers measured 0.21% in Sample 1, and values of 2.79% (cylinder) and 2.65% (airbag) were recorded in Sample 7, corresponding to a relative deviation of only 5.0%. C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e8\u003c/sub\u003e was identical (0.08%) in both Sample 2 and Sample 3.\u003c/p\u003e\u003cp\u003eThese results demonstrate that, under strictly controlled sampling conditions, both containers offer equivalent initial preservation performance for hydrocarbon gases.\u003c/p\u003e\u003cp\u003e(2) Comparative analysis of helium concentration\u003c/p\u003e\u003cp\u003eFor trace helium, the two containers showed good correlation but systematic differences (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(e)). The helium concentration ranged from 177.55 to 865.54 ppm (avg. 488.99 ppm) in steel cylinders and from 213.38 to 819.06 ppm (avg. 479.88 ppm) in airbags.\u003c/p\u003e\u003cp\u003eIn seven of the nine samples, airbag values were lower than those from cylinders, with an average deviation of -1.9%. The largest difference occurred in Sample 5 (865.54 ppm vs. 819.06 ppm; relative deviation 5.4%), while the smallest was in Sample 2 (647.30 ppm vs. 650.25 ppm; relative deviation 0.5%).\u003c/p\u003e\u003cp\u003eThis pattern suggests that even under immediate detection conditions, aluminum-plastic airbags may allow slight helium permeation loss or dilution.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of gas content between dual-valve high-pressure steel cylinder and aluminum-plastic airbag (a) Gas content of dual-valve high-pressure steel cylinder in the immediate comparative experiment\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"10\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eGas components\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"9\" nameend=\"c10\" namest=\"c2\"\u003e\u003cp\u003eSamples in steel cylinder\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSample1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSample2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSample3\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eSample4\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSample5\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eSample6\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eSample7\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eSample8\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u003cp\u003eSample9\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCH\u003csub\u003e4\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e92.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e94.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e89.68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e96.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e94.74\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e94.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e95.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e92.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e95.86\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e2.79\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.22\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e8\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e2.94\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e4.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e7.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.65\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u003csub\u003e2\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e6.60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eO\u003csub\u003e2\u003c/sub\u003e /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e78.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e299.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e166.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e86.98\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e207.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e44.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e60.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e63.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e146.80\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHe /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e432.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e647.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e409.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e552.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e865.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e177.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e456.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e227.90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e622.87\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eH\u003csub\u003e2\u003c/sub\u003e /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e221.72\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e190.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e149.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e213.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e220.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e2.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e191.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e2.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e114.55\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e(b) Gas content of aluminum-plastic airbag in the immediate comparative experiment\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"10\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eGas components\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"9\" nameend=\"c10\" namest=\"c2\"\u003e\u003cp\u003eSamples in aluminum-plastic airbag\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSample1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSample2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSample3\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eSample4\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSample5\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eSample6\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eSample7\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eSample8\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u003cp\u003eSample9\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCH4 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e91.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e93.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e88.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e94.90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e92.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e91.95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e92.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e90.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e92.70\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC2H6 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e2.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.17\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC3H8 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e0.14\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCO2 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e2.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e4.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e6.77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.58\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN2 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e7.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e2.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e1.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.92\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.90\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eO2 /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2811.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3204.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e3526.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e4819.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e5260.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e2606.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e5274.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e2668.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e3138.41\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHe /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e438.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e650.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e408.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e537.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e819.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e213.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e461.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e221.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e564.76\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eH2 /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e218.86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e196.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e144.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e334.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e222.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e180.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e113.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"10\"\u003e(3) Permeation of Air Components\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eDifferences in air components (N\u003csub\u003e2\u003c/sub\u003e, O\u003csub\u003e2\u003c/sub\u003e) were most pronounced (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(g, h)). N\u003csub\u003e2\u003c/sub\u003e concentrations were generally elevated in airbags: in Sample 1, the airbag value (1.55%) was 2.2 times that in the cylinder (0.71%), and in Sample 6, it was 14 times higher (0.84% vs. 0.06%).\u003c/p\u003e\u003cp\u003eO\u003csub\u003e2\u003c/sub\u003e differences were even more striking. In Sample 1, the O\u003csub\u003e2\u003c/sub\u003e concentration in the airbag (2811.20 ppm) was 35.9 times that in the cylinder (78.30 ppm). In Sample 7, the airbag value (5274.96 ppm) was 87.5 times the cylinder value (60.29 ppm) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), indicating severe air infiltration in aluminum-plastic airbags.\u003c/p\u003e\u003cp\u003e(4) Other Components\u003c/p\u003e\u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e concentrations showed relatively small differences between the two containers (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(d)), with an average relative deviation of 3.8%.\u003c/p\u003e\u003cp\u003eH\u003csub\u003e2\u003c/sub\u003e exhibited more complex behavior (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(f)): H\u003csub\u003e2\u003c/sub\u003e was undetected (0.00 ppm) in airbags for Samples 6 and 8, whereas steel cylinders measured 2.24 ppm\u0026mdash;suggesting possible adsorption of hydrogen by the aluminum-plastic material. In other samples, H\u003csub\u003e2\u003c/sub\u003e concentrations were relatively consistent, with an average relative deviation of 12.3%.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section3\"\u003e\u003ch2\u003e3.1.2 Results of the time-sensitive experiment\u003c/h2\u003e\u003cp\u003eThe time-sensitive experiment systematically analyzed changes in gas composition within steel cylinders and aluminum-plastic airbags over time to evaluate the medium- and long-term storage performance of both container types. The results reveal significant differences in the preservation of gas components between the two containers, with these differences becoming more pronounced as storage duration increased.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e(1) Stability of hydrocarbon gas components\u003c/p\u003e\u003cp\u003eHydrocarbon gases (CH\u003csub\u003e4\u003c/sub\u003e, C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e, C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e8\u003c/sub\u003e) in steel cylinders demonstrated excellent stability over the 30-day storage period (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e(a-c)). For instance, in Sample 1, CH\u003csub\u003e4\u003c/sub\u003e concentration changed marginally from 95.59\u0026ndash;95.99% (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), representing a fluctuation of less than 0.5%. C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e remained stable between 1.21% and 1.23%.\u003c/p\u003e\u003cp\u003eIn contrast, aluminum-plastic airbags exhibited severe hydrocarbon loss: CH\u003csub\u003e4\u003c/sub\u003e in Sample 1 decreased sharply from 92.70\u0026ndash;11.04%, corresponding to a relative decay rate of 88.1%. C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e also declined from 1.17\u0026ndash;0.21%. Moreover, C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e8\u003c/sub\u003e in Sample 3 displayed abnormal variation (from 0.36\u0026ndash;391.85%, then down to 61.81%), suggesting possible sample contamination or analytical anomalies.\u003c/p\u003e\u003cp\u003e(2) Helium preservation performance\u003c/p\u003e\u003cp\u003eMarked differences were observed in helium preservation between the two containers. Helium concentration in steel cylinders decreased slowly and uniformly (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e(e)): in Sample 1, it declined from 661.22 ppm to 582.09 ppm over 30 days (decay rate: 12.0%); in Sample 2, from 234.19 ppm to 200.37 ppm (decay rate: 14.4%).\u003c/p\u003e\u003cp\u003eHelium loss was more severe in aluminum-plastic airbags: Sample 1 decreased from 664.76 ppm to 141.50 ppm (decay rate: 78.7%); Sample 2 decayed at 14.4%. Notably, in Sample 3, helium was nearly entirely lost after 15 days (from 456.07 ppm to 0.35 ppm), indicating major leakage or permeation issues.\u003c/p\u003e\u003cp\u003e(3) Time-dependent permeation of air components\u003c/p\u003e\u003cp\u003eChanges in air components (N\u003csub\u003e2\u003c/sub\u003e, O\u003csub\u003e2\u003c/sub\u003e) further confirmed the permeation defects of aluminum-plastic airbags. N\u003csub\u003e2\u003c/sub\u003e and O\u003csub\u003e2\u003c/sub\u003e concentrations remained stable in steel cylinders throughout the experiment (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e(g, h)): in Sample 1, O\u003csub\u003e2\u003c/sub\u003e held constant at 0.01%, and N\u003csub\u003e2\u003c/sub\u003e varied only between 0.96% and 1.00%.\u003c/p\u003e\u003cp\u003eIn aluminum-plastic airbags, however, air components increased substantially over time: O\u003csub\u003e2\u003c/sub\u003e in Sample 1 rose from 0.31\u0026ndash;19.59% (a 63-fold increase), and N\u003csub\u003e2\u003c/sub\u003e increased from 1.90\u0026ndash;35.94% (an 18.9-fold increase), demonstrating continuous infiltration of external air.\u003c/p\u003e\u003cp\u003e(4) Variation patterns of other gases\u003c/p\u003e\u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e remained stable in steel cylinders (e.g., Sample 1: 1.65%~1.68%) but decreased in airbags (Sample 1: 1.58\u0026ndash;0.27%) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e(d)).\u003c/p\u003e\u003cp\u003eH\u003csub\u003e2\u003c/sub\u003e exhibited more complex behavior: concentrations were stable in steel cylinders (Sample 1: 114.55\u0026ndash;119.61 ppm) but declined steadily in airbags (Sample 1: 113.00 ppm to 0.00 ppm) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e(f)), suggesting possible adsorption or catalytic reaction with the airbag material.\u003c/p\u003e\u003cp\u003e(5) Variability across samples\u003c/p\u003e\u003cp\u003eDifferent samples responded differently to storage conditions. For example, the helium decay rate in Sample 2 (14.4%) was much lower than that in Sample 1 (78.7%) when stored in airbags, possibly due to variations in initial composition, micro-environmental conditions, or individual container differences. Overall, however, the preservation performance of aluminum-plastic airbags remained significantly inferior to that of steel cylinders.\u003c/p\u003e\u003cp\u003eIn summary, the time-sensitive experiment confirms the superior performance of steel cylinders in long-term gas storage. Their excellent sealing and chemical stability maintain the integrity of all components\u0026mdash;including trace helium\u0026mdash;over 30 days. In contrast, the permeability of aluminum-plastic airbags leads to severe loss of target components and significant air ingress, fundamentally altering sample composition. These findings underscore the importance of storage container selection based on intended storage duration and detection accuracy in helium-bearing natural gas studies.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eChanges in gas content over time in dual-valve high-pressure steel cylinders and aluminum-plastic airbags in the time-sensitive experiment (a) Gas content of dual-valve high-pressure steel cylinder in the time-sensitive experiment\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"13\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eGas components\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"12\" nameend=\"c13\" namest=\"c2\"\u003e\u003cp\u003eSamples in steel cylinder\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003eSample1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e\u003cp\u003eSample2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c13\" namest=\"c10\"\u003e\u003cp\u003eSample3\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFirst test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAfter 7 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAfter 15 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eAfter 30 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eFirst test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eAfter 7 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eAfter 15 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eAfter 30 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u003cp\u003eFirst test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c11\"\u003e\u003cp\u003eAfter 7 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c12\"\u003e\u003cp\u003eAfter 15 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c13\"\u003e\u003cp\u003eAfter 30 days\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCH4 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e95.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e95.86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e95.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e95.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e93.43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e92.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e91.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e92.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e95.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e94.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC2H6 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e2.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e2.78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e0.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e0.50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC3H8 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e421.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e421.81\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCO2 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e7.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e6.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e6.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e7.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e1.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e186.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e187.28\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eO2 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e94.81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e93.88\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN2 /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.98\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e0.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e0.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e2.78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e2.77\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHe /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e661.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e622.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e621.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e582.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e234.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e226.94\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e214.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e200.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e493.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e431.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eH2 /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e119.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e114.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e119.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e116.94\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e183.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e184.89\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e1.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e1.17\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e(b) Gas content of aluminum-plastic airbag in the time-sensitive experiment\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\u003e\u003ccolgroup cols=\"13\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eGas components\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"12\" nameend=\"c13\" namest=\"c2\"\u003e\u003cp\u003eSamples in aluminum-plastic airbag\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003eSample1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e\u003cp\u003eSample2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c13\" namest=\"c10\"\u003e\u003cp\u003eSample3\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFirst test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAfter 7 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAfter 15 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eAfter 30 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eFirst test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eAfter 7 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eAfter 15 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eAfter 30 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u003cp\u003eFirst test\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c11\"\u003e\u003cp\u003eAfter 7 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c12\"\u003e\u003cp\u003eAfter 15 days\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c13\"\u003e\u003cp\u003eAfter 30 days\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCH\u003csub\u003e4\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e92.70\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e90.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e85.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e11.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e90.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e90.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e91.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e90.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e91.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e92.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e0.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e23.57\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e2.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e2.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e1.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e41.71\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e8\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e0.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e0.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e391.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e61.81\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e6.84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e6.84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e6.68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e6.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e1.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e180.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eO\u003csub\u003e2\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e2.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e19.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e0.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e0.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e92.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e18.90\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u003csub\u003e2\u003c/sub\u003e /%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e8.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e35.94\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e1.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e1.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e1.69\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e2.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHe /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e664.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e538.84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e450.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e141.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e204.98\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e182.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e172.79\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e175.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e456.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e415.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eH\u003csub\u003e2\u003c/sub\u003e /ppm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e113.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e103.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e93.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e184.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e\u003cp\u003e182.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e\u003cp\u003e1.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003e3.2 Discussion\u003c/h2\u003e\u003cp\u003eThrough the immediate comparative experiment and the time-sensitive experiment, the preservation performance of steel cylinders and aluminum-plastic airbags for helium-bearing natural gas samples was systematically evaluated. The results reveal significant differences in the preservation of gas components between the two containers, with these differences fundamentally originating from their material properties and structural designs.\u003c/p\u003e\u003cdiv id=\"Sec15\" class=\"Section3\"\u003e\u003ch2\u003e3.2.1 Mechanism analysis of immediate differences\u003c/h2\u003e\u003cp\u003eThe compositional differences observed in the immediate comparative experiment were primarily determined by the material properties of the two container types. The significantly elevated concentrations of N\u003csub\u003e2\u003c/sub\u003e and O\u003csub\u003e2\u003c/sub\u003e in the aluminum-plastic airbags indicate that air infiltration occurred even during the initial sampling stage. For example, the O\u003csub\u003e2\u003c/sub\u003e concentration in Sample 1 was 35.9 times that in the steel cylinder. This phenomenon can be attributed to structural limitations of the aluminum-plastic composite film. Although the aluminum foil layer serves as the primary barrier, molecular gaps in the polyethylene or polyamide plastic layers and micro-pores at the heat-sealed edges provide permeation pathways for small gas molecules.\u003c/p\u003e\u003cp\u003eIn contrast, the steel cylinders employ a 316 stainless steel monolithic structure and metal-face-sealed valves. The dense metallic crystal structure and high-precision machining achieve an nearly defect-free sealing effect, fundamentally preventing air infiltration.\u003c/p\u003e\u003cp\u003eIt is noteworthy that, despite the air permeation issue, the aluminum-plastic airbags maintained relatively good consistency with steel cylinders in the initial capture of helium and hydrocarbon gases, with an average relative deviation of 2.2%. This indicates that under strictly controlled immediate sampling conditions, aluminum-plastic airbags can meet short-term gas storage requirements.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\u003ch2\u003e3.2.2 Mechanism analysis of time-dependent differences\u003c/h2\u003e\u003cp\u003eThe results of the time-dependent experiment showed that as the storage time increased, the performance difference between the two containers showed a significant widening trend. The severe loss of helium in aluminum-plastic airbags, such as the 30-day decay rate of 78.7% in Sample 1, can be explained by the physical properties and permeation behavior of helium. Helium molecules possess the smallest kinetic diameter and an extremely high diffusion coefficient, allowing them to easily penetrate microscopic defects and polymer chain gaps in the aluminum-plastic composite film. This permeation process follows Fick\u0026rsquo;s law of diffusion. The helium transmission rate may be positively correlated with the concentration difference across the membrane, the material\u0026rsquo;s permeability coefficient, and inversely related to membrane thickness. However, the barrier performance of the aluminum-plastic composite structure is inherently insufficient to contain helium due to its ultra-light characteristics. In addition to material permeability, the valves on aluminum-plastic airbags may develop sealing deficiencies with repeated use, potentially leading to further gas leakage and composition changes over time.\u003c/p\u003e\u003cp\u003eIn contrast, the steel cylinders demonstrated exceptional long-term stability, with a helium decay rate of only 12.0% over 30 days. This performance is attributed to the face-centered cubic (FCC) dense crystalline lattice structure of 316 stainless steel, which has an extremely low helium permeability coefficient, effectively inhibiting helium diffusion. In addition, the dual-valve design and metal-face-seal interface completely eliminate leakage risks, ensuring reliable long-term storage.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section3\"\u003e\u003ch2\u003e3.2.3 Error analysis\u003c/h2\u003e\u003cp\u003eThis study implemented multiple measures to strictly control potential errors. ①All samples were taken from the same gas source at the same time to ensure initial compositional consistency. ②A standardized sampling procedure was used with precise control of purging cycles (4 times) and sampling pressure (2.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 MPa). All experiments were performed by the same operator to minimize human-induced variations. ③The same Agilent 7890B gas chromatograph was used under consistent conditions to avoid instrumental systematic error, and the instrument was calibrated with standard reference gases before each sample set to ensure detection accuracy. ④Three replicate samples were used in each experimental group, and repeatability was evaluated using relative standard deviation (RSD\u0026thinsp;\u0026lt;\u0026thinsp;2%).\u003c/p\u003e\u003cp\u003eThese measures effectively eliminated extraneous interfering factors, confirming that the storage container itself is the primary cause of the observed differences. Potential residual errors may include minor sample individuality, slight instrumental deviations (RSD\u0026thinsp;\u0026lt;\u0026thinsp;2%), and subtle fluctuations in the storage environment. However, the magnitude of these errors is significantly smaller than the compositional changes resulting from container differences, and thus they do not substantially affect the overall conclusions.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003e(1) Steel cylinders perform much better than aluminum-plastic airbags at preserving helium-bearing natural gas samples. Experiments showed that steel cylinders have a dense metal structure and high-quality seals. These features effectively prevent helium from leaking and block outside air from entering. Over 30 days, helium levels in steel cylinders decreased only slowly and steadily. The decay rate was between 12.0% and 14.4%. During this period, all other major gas components remained stable. These results confirm that steel cylinders are reliable for long-term storage and high-precision analysis.\u003c/p\u003e\u003cp\u003e(2) Aluminum-plastic airbags can be used for short-term (\u0026lt;\u0026thinsp;7 days) storage under strictly controlled sampling conditions, but are not recommended for medium to long term storage of trace helium due to material permeation limitations. Although immediate comparative tests show acceptable initial capture performance, the composite film cannot effectively retain helium, which has a small molecular kinetic diameter of 0.26 nm. This leads to a gradual yet substantial loss of helium concentration, with decay rates reaching up to 78.7%. In addition, external air, such as N\u003csub\u003e2\u003c/sub\u003e and O\u003csub\u003e2\u003c/sub\u003e, may gradually infiltrate the bags, which can alter sample composition over time. Therefore, if such bags are used, it is essential to complete testing promptly after sampling to minimize composition changes and ensure result reliability.\u003c/p\u003e\u003cp\u003e(3) The selection of storage containers is a critical factor affecting the accuracy of helium-bearing natural gas detection. Experimental results indicate that the permeability of the container material is the primary cause of data deviation, with its influence far exceeding secondary factors such as analytical instrument errors. Therefore, in helium resource exploration and evaluation, storage container performance must be a core consideration in quality control. Priority should be given to using high-airtightness steel cylinders to avoid misjudgment of resources due to inappropriate container selection.\u003c/p\u003e\u003cp\u003e(4) It is essential to develop new types of storage containers and establish standardized sampling methods for trace gases. In light of the permeability limitations of aluminum-plastic airbags, future efforts should prioritize the development of composite materials with improved barrier properties. Researchers should also systematically examine how temperature and pressure affect helium retention. Furthermore, clear quantitative guidelines for container selection should be defined, taking into account gas composition, concentration, and expected storage time. These improvements will offer a scientific foundation for updating sampling protocols for helium-bearing natural gas and significantly increase the reliability and accuracy of trace helium detection.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eData availability statement\u003c/p\u003e\n\u003cp\u003eThe original contributions presented in the study are included in\u0026nbsp;the article/Supplementary material, further inquiries can be directed\u0026nbsp;to the corresponding author.\u003c/p\u003e\n\u003cp\u003eAuthor Contributions\u003c/p\u003e\n\u003cp\u003eConceptualization, K.Y. and X.F.; methodology, K.Y. and X.X.; software, J.Y.; validation, J.Y., S.B. and K.Y.; formal analysis, K.Y.; investigation, K.Y.; resources, Y.X.; data curation, K.Y. and X.F; writing\u0026mdash;original draft preparation, X.F.; writing\u0026mdash;review and editing, X.F.; visualization, K.Y.; supervision, K.Y.; project administration, K.Y.; funding acquisition, K.Y. and X.F.. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThe author(s) declare that financial support was received\u0026nbsp;for the research, authorship, and/or publication of this article.\u0026nbsp;China Geological Survey Geological Survey Special Project \u0026quot;National Survey of Helium Resources\u0026quot; (no. DD20240201203) and \u0026quot;Assessment of Oil and Potash Combined Exploration Resources in the Huangshi Area of the Western Qaidam Basin\u0026quot; (no.\u0026nbsp;DD20230203611), Academy of Geological Sciences Basal Research Fund \u0026quot;Sequence stratigraphic configuration, spatiotemporal differences, and controlling factors of the Upper Carboniferous mixed layer system in the Ounan Depression of the eastern Qaidam Basin\u0026quot; (no.\u0026nbsp;JKYQN202410).\u003c/p\u003e\n\u003cp\u003eAcknowledgments\u003c/p\u003e\n\u003cp\u003eWe would like to express our gratitude to Shunshuang Jin, Chao Wang, Degang Mu, Xianglong Meng and Tuo Lin from Oil and Gas Resources Survey, China Geological Survey for their valuable support and inspiration provided throughout the writing process.\u003c/p\u003e\n\u003cp\u003eConsent to Participate declaration\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003eEthics and Consent to Publish declarations\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003eConflicts of Interest\u003c/p\u003e\n\u003cp\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.\u003c/p\u003e\n\u003cp\u003ePublisher\u0026rsquo;s note\u003c/p\u003e\n\u003cp\u003eAll claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eTao Shizhen C, Yue Y. Classification system of helium resources and zones in China, effectiveness and enrichment mode of controlling factors [J]. Nat Gas Earth Sci. 2024;35(05):869\u0026ndash;89.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQin Shengfei D, Lirong T, Gang, et al. Helium Enrichment Theory and Exploration Ideas for Rich Helium Resources [J]. Pet Explor Dev. 2024;51(05):1160\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTao Shizhen Y, Yiqing C, Yue, et al. Geological conditions, genesis mechanisms, and enrichment laws of helium gas resources [J]. Pet Explor Dev. 2024;51(02):436\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTao Xiaowan L, Jianzhong Z, Libin, et al. The current status of helium resources in China and the discovery of the first super large helium rich reserve: Hetianhe gas field [J]. Earth Sci. 2019;44(03):1024\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQin Shengfei L, Jiyuan W. Helium Enrichment Model of Rich Helium Natural Gas Reservoirs in Oil and Gas Basins in China [J]. Nat Gas Ind. 2022;42(07):125\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChao Haide C, Jianzhou W. Discovery and Enrichment Mechanism of Water Soluble Helium Resources in Chaidamu Basin [J]. Northwest Geol. 2022;55(04):61\u0026ndash;73. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.19751/j.cnki. 61-1149/p.2022.04.005\u003c/span\u003e\u003cspan address=\"10.19751/j.cnki. 61-1149/p.2022.04.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu Chenglin W, Xinpei C, Changbo, et al. Development prospects of unconventional oil and gas and renewable energy in China [J]. World Petroleum Ind. 2025;32(03):12\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang Xue L, Chenglin F, Liyong, et al. Geochemical characteristics and enrichment models of helium-bearing natural gas in Sulige gas field, Ordos Basin [J]. Natural Gas Geosciences; 2025.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSong H, Liwu L, Qingyan T, et al. Research progress and significance of common rare gas sampling containers [J]. Geol Sci. 2022;57(01):274\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang Chuanli M, Jun W, Kai, et al. Analysis of the Influence of Gas Sampling Containers on Carbon Isotope Values of Hydrocarbons [J]. Low Permeability Oil and Gas Fields; 2012. pp. 125\u0026ndash;8. 1.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang Fuyuan Z, Yana YM. Analysis of Natural Gas Composition and Uncertainty in Physical Property Parameter Calculation [J]. Petroleum Nat Gas Chem Ind, 2006 (01): 65\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi C, Ji Q, Yongjie C et al. The Influence of Normalization on Uncertainty in Natural Gas Composition Analysis [J]. Petroleum Ind Tech Supervision \u003csub\u003e2\u003c/sub\u003e016, 32 (03): 35\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTang Meng L, Qin CY. Research and Application of Natural Gas Analysis and Testing Technology [J]. Petroleum and Natural Gas Chemical Industry, 2008 (S1): 42\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZou Yi L, Qingyong C, Jianfa et al. Physical simulation experiment study on competitive dissolution of helium gas in helium rich reservoirs [J]. Coalf Geol Exploration \u003csub\u003e2\u003c/sub\u003e025, 53 (06): 96\u0026ndash;108.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang Dongliang M, Chenghua L. The influence of sampling devices on the detection results of carbon isotopes in natural gas [J]. Nat Gas Earth Sci. 2010;21(02):345\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXing Lantian L, Zhongping Z. The influence of different sampling devices and storage times on the carbon, hydrogen, and oxygen isotopes of non hydrocarbon gases [J]. Nat Gas Earth Sci. 2020;31(04):483\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZeng Wenping H, Liming L, Qin, et al. Development Status and Prospects of Natural Gas Analysis and Detection Technology in China [J]. Petroleum Nat Gas Chem Ind. 2013;42(01):68\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi Cheng Z. Determination of Non-methane Hydrocarbons in Ambient Air by Canister Sampling-Transfer Bag Injection-Gas Chromatography [J]. Arid Environ Monit. 2024;38(1). 10.3969/ j.issn.1007-1504.2024.01.002.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGeorge V. Chilingarian,Teh Fu Yen. Petroleum geochemistry and geology [J]. Sed Geol. 1980. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/0037-0738(80)90018-4\u003c/span\u003e\u003cspan address=\"10.1016/0037-0738(80)90018-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi Cheng S. Zhuang. Comparison Study of Non Methane Total Hydrocarbons Determined by Different Sampling and Storage Methods [J]. Environ Sci Technol. 2016, (0s2).335\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKong Lingchang Research on Field Gas Samplers and Sampling Methods. [J] Seismic Geol, 1992, (03):286\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZeng Wenping M, Jian. Chang Honggang Discussion on the Analysis and Comparison of Natural Gas Composition [J]. Petroleum Ind Tech Superv\u003csub\u003e,2\u003c/sub\u003e008 (08): 9\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNajman J, Sliwka I. The Cryogenic Enrichment System in Chromatographic Analysis of Noble Gases in Groundwater[J]. Acta Physica Polonica, A. General Physics, Physics of Condensed Matter, Optics and Quantum Electronics, Atomic and Molecular Physics, Applied Physics,2016,130(3):737\u0026ndash;742. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.12693/APhysPolA.130.737.3\u003c/span\u003e\u003cspan address=\"10.12693/APhysPolA.130.737.3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen Gengliang. On the Traceability of Natural Gas Composition Analysis [J]. Petroleum Nat Gas Chem Ind, 2008 (03): 243\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTang Meng C, Yongjie. Conventional analysis methods and standardization of natural gas composition [J]. Petroleum and Natural Gas Chemical Industry; 2002. pp. 64\u0026ndash;70. S1.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTao Cheng L, Wenhui Y, Huamin, et al. Joint measurement technology and application of rare gas concentration and isotope ratio in natural gas [J]. J Mass Spectrom. 2018;39(02):201\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen Gengliang. Analysis methods and instruments for natural gas quality indicators [J]. Urban Gas, 2003 (08): 3\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang J. Preservation of gas samples and changes in their composition [J]. Monit arid Environ, 1995, (03):172\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZou Wei. Analysis of Common Methods for Natural Gas Sampling and Their Impact on Analysis Results [J]. J Metrol Sci Technol. 2021;65(07):65\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXu Quanmin Z, Zhijing H, Xiaobo et al. Analysis of the influencing factors of environmental air sample collection [J]. Chem Res Application \u003csub\u003e2\u003c/sub\u003e010, 22 (12): 1605\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi Wei B, Chengzhi. Environ Dev. 2019;31(03):97\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.16647/j.cnki. cn15-1369/X.2019.03.056\u003c/span\u003e\u003cspan address=\"10.16647/j.cnki. cn15-1369/X.2019.03.056\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Zhou Yongjun Application of Fluoropolymer Gas Bags in the Determination of Non Methane Total Hydrocarbons [J].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYao Cheng. Research on the collection of volatile organic compounds from fixed pollution sources using airbag method [J]. Environ Dev. 2017;29(08):122\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOda J-I, Hayashi Y, Asada Y. et.al. Simultaneous Determination of Inorganic Nitrogen Species in Seawater by Ion Chromatography Utilization of Gas-diffusion/o-Phthalaldehyde Method for Fluorometric Determination of Ammonium Ion [J].Bunseki Kagaku. 2019, 68(3):189\u0026ndash;93. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2116/bunsekikagaku.68.189\u003c/span\u003e\u003cspan address=\"10.2116/bunsekikagaku.68.189\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWenping Z, Qin L. Analysis of Differences and Similarities in Natural Gas Quality Detection Methods between Domestic and Foreign Standards [J]. Petroleum Nat Gas Chem Ind. 2015;44(03):104\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFan Liyong W, Jianshe H, Aiping. The geochemical characteristics, genesis sources, and main controlling factors of helium-bearing natural gas in Sulige gas field, Ordos Basin [J]. Nat Gas Geosci. 2025;36(3):399\u0026ndash;412. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.11764/j.issn. 1672-1926.2024.10.012\u003c/span\u003e\u003cspan address=\"10.11764/j.issn. 1672-1926.2024.10.012\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYu Z, Liyong F, Junfeng R. The Cambrian Ordovician natural gas reservoir formation model and favorable exploration areas in the Ordos Basin [J]. Nat Gas Ind. 2024;44(8):44\u0026ndash;57. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3787/j.issn.1000-0976.2024.004\u003c/span\u003e\u003cspan address=\"10.3787/j.issn.1000-0976.2024.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHou Fanghao F, Shaoxian D, Zhaoxiong. Sedimentary Environment and Lithofacies Development Characteristics of the Majiagou Formation in the Middle Ordovician of the Ordos Basin [J]. J Sedimentology. 2003;21(1):106\u0026ndash;12. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3969/j.issn.1000-0550.2003.01.016\u003c/span\u003e\u003cspan address=\"10.3969/j.issn.1000-0550.2003.01.016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTao L, Songyu M, Xiaohui L. The Sandbody Stacking Model and Oil and Gas Development Significance of Permian Shanxi Formation in Daniudi Gas Field, Ordos Basin [J]. Lithological Oil Gas Reservoirs. 2024;36(2):147\u0026ndash;59. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.12108/yxyqc.20240214\u003c/span\u003e\u003cspan address=\"10.12108/yxyqc.20240214\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHe Faqi W, Fubin W, Jie. The distribution pattern of helium gas in Dongsheng gas field in Ordos Basin and the discovery of a super large helium rich gas field [J]. Petroleum Experimental Geol. 2022;44(1):1\u0026ndash;10. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.11781/sysydz202201001\u003c/span\u003e\u003cspan address=\"10.11781/sysydz202201001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMa Yong C, Jianfa X, Zhiyuan. Potential and Enrichment Mechanism of Helium Resources in Unconventional Natural Gas [J]. Acta Petroleum Sinica. 2025;46(2):440\u0026ndash;455482. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.7623/syxb202502011\u003c/span\u003e\u003cspan address=\"10.7623/syxb202502011\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen Jianfa F, Rao. Characteristics and main controlling factors of helium rich natural gas reservoirs [J]. Acta Petroleum Sinica. 2022;43(11):1652\u0026ndash;63. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.7623/syxb202211012\u003c/span\u003e\u003cspan address=\"10.7623/syxb202211012\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu Chenglin Z, Yaxiong W, Xinpei. Comparison and Implications of Helium Geological Conditions and Resource Potential between China and the United States [J]. World Petroleum Ind. 2024;31(2):1\u0026ndash;10. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.20114/j.issn.1006-0030.202307001\u003c/span\u003e\u003cspan address=\"10.20114/j.issn.1006-0030.202307001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGeneral Administration of Quality Supervision. Inspection and Quarantine of the People's Republic of China Composition analysis of natural gas by gas chromatography: GB 13610\u0026thinsp;\u0026ndash;\u0026thinsp;2020 [S]. Beijing: China Standard; 2020.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"discover-sustainability","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"disu","sideBox":"Learn more about [Discover Sustainability](https://www.springer.com/43621)","snPcode":"","submissionUrl":"","title":"Discover Sustainability","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Helium gas, Storage containers, Steel cylinder, Aluminum-plastic airbag, Helium content test","lastPublishedDoi":"10.21203/rs.3.rs-7524670/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7524670/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eHelium is a critical strategic resource that underpins high-tech industries and national security. The accuracy of its concentration measurement is essential for reliable helium resource exploration and evaluation. Due to its small molecular size (0.26 nm), high diffusion coefficient, and typical occurrence in trace amounts (\u0026lt;\u0026thinsp;1%) in natural gas, helium poses significantly greater challenges for sample collection and storage compared to conventional natural gas. Thus, the selection of storage containers is a crucial factor influencing detection accuracy. However, systematic studies comparing the performance of commonly used containers\u0026mdash;such as dual-valve high-pressure steel cylinders and aluminum-plastic gas bags\u0026mdash;for storing helium-bearing natural gas are still lacking. This study systematically evaluated these two container types through controlled experiments. The immediate comparative experiment involved parallel sampling from the same gas source using both containers, followed by prompt component analysis to compare initial detection results. The time-sensitive experiment monitored compositional changes in samples stored in both containers over 7, 15, and 30 days to assess preservation performance and variation in helium concentration over time. Variables including gas source, sampling pressure (2.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 MPa), and purging cycles (4 times) were strictly controlled to ensure result reliability. Results revealed that during immediate detection, both containers showed consistent helium content, with an average relative deviation of 1.9%. However, concentrations of air components such as N2 and O\u003csub\u003e2\u003c/sub\u003e were significantly higher in aluminum-plastic airbags\u0026mdash;O\u003csub\u003e2\u003c/sub\u003e levels in some samples reached 35.9 to 87.5 times those in steel cylinders. In the time-sensitive experiment, steel cylinders demonstrated excellent stability, with a helium decay rate of only 12.0%~14.4% over 30 days. In contrast, aluminum-plastic airbags exhibited severe helium loss, with decay rates ranging from 14.4\u0026ndash;78.7%. Some samples nearly completely lost helium after 15 days. Furthermore, hydrocarbon components (e.g., CH\u003csub\u003e4\u003c/sub\u003e) decreased sharply in aluminum-plastic airbags\u0026mdash;with a decay rate of up to 88.1% within 30 days\u0026mdash;while air component concentrations increased by 18.9 to 63 times. In conclusion, dual-valve high-pressure steel cylinders, with their superior airtightness and chemical stability, outperform aluminum-plastic airbags significantly in storing helium-bearing natural gas. They are recommended as the preferred container for long-term (\u0026gt;\u0026thinsp;15 days) storage and high-precision helium detection. Aluminum-plastic airbags are only suitable for short-term (\u0026lt;\u0026thinsp;7 days) temporary storage and require strict monitoring of air contamination risks. This study provides key data support for optimizing helium-bearing natural gas detection protocols and enhancing the reliability of helium resource assessment.\u003c/p\u003e","manuscriptTitle":"Impact of Sampling Containers on the Analytical Results of Helium-Bearing Natural Gas","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-22 15:56:05","doi":"10.21203/rs.3.rs-7524670/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-01-19T06:40:37+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-12T12:13:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"232532702554248805074882636486486471443","date":"2025-12-30T14:45:00+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-10T02:27:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"308896736866848866382030528067821042817","date":"2025-11-30T19:14:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"211288508386122638436806875379662389544","date":"2025-11-18T14:40:20+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-10T19:52:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"53328782417500202447837618262711477752","date":"2025-09-14T14:03:42+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-14T13:42:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-09T12:45:35+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-09T12:44:41+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Sustainability","date":"2025-09-03T08:30:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"discover-sustainability","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"disu","sideBox":"Learn more about [Discover Sustainability](https://www.springer.com/43621)","snPcode":"","submissionUrl":"","title":"Discover Sustainability","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d968aa7e-3718-48b6-bf2c-de3dfd9c7397","owner":[],"postedDate":"September 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-30T16:23:27+00:00","versionOfRecord":{"articleIdentity":"rs-7524670","link":"https://doi.org/10.1007/s43621-026-03047-6","journal":{"identity":"discover-sustainability","isVorOnly":false,"title":"Discover Sustainability"},"publishedOn":"2026-03-29 16:10:35","publishedOnDateReadable":"March 29th, 2026"},"versionCreatedAt":"2025-09-22 15:56:05","video":"","vorDoi":"10.1007/s43621-026-03047-6","vorDoiUrl":"https://doi.org/10.1007/s43621-026-03047-6","workflowStages":[]},"version":"v1","identity":"rs-7524670","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7524670","identity":"rs-7524670","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}