Gas chromatographic analyzer based on cloud data management and gas component detection method

Abstract

The invention discloses a gas chromatographic analyzer based on cloud data management and a gas component detection method. The analyzer comprises a sample introduction module, a separation module, a detection module, an analysis module and a communication module. The separation module adopts a chromatographic separation column filled with a hydrophobic modified stationary phase material, and chromatographic separation of hydrogen and methane is realized under the pushing of air carrier gas. The detection module judges the effectiveness of a sample through carbon dioxide concentration detection and distinguishes alveolar gas and oral cavity dead space gas. The separation optimization unit adjusts the carrier gas flow and / or the column temperature to enable the retention time difference to meet a preset condition, pulse heating control accelerates baseline recovery, and overlapping of adjacent peaks is avoided. And the communication module is connected with a cloud server to realize uploading of detection data and remote updating of drift compensation parameters. According to the invention, the dependence on high-purity inert carrier gas is eliminated, the use cost is reduced, and the reliability of a detection result is improved.

Description

Technical Field

[0001] This invention relates to the field of chromatography analysis technology, and in particular to a gas chromatograph and gas component detection method based on cloud data management. Background Technology

[0002] Hydrogen and methane are important metabolic indicators in human exhaled breath, and their concentration changes are closely related to intestinal flora activity and digestive and absorptive functions. Clinically, detecting the concentration of hydrogen and methane in exhaled breath can be used to assist in the diagnosis of digestive system diseases such as small intestinal bacterial overgrowth, lactose intolerance, fructose malabsorption, pancreatic exocrine dysfunction, and oral-cecal transit time. Therefore, developing analytical instruments that can accurately and rapidly detect the concentration of hydrogen and methane in exhaled breath has significant clinical application value.

[0003] Gas chromatography is a classic analytical technique for separating and detecting components in gas mixtures. It boasts advantages such as high separation efficiency and good detection sensitivity, and has been widely applied in the field of exhaled gas analysis. Traditional gas chromatographs typically use high-purity inert gases such as helium, nitrogen, or argon as carrier gases. While this achieves good separation results, it suffers from drawbacks such as high carrier gas costs, the need for regular gas cylinder replacements, and relatively large equipment size, limiting its widespread application in primary healthcare institutions and portable testing scenarios.

[0004] Furthermore, the thermal conductivity detectors or flame ionization detectors commonly used in traditional gas chromatographs have certain limitations in detecting hydrogen and methane. Thermal conductivity detectors are sensitive to the difference in thermal conductivity between hydrogen and the carrier gas; when air is used as the carrier gas, the detection sensitivity decreases significantly. While flame ionization detectors have high sensitivity to methane, their response to hydrogen is weak, and they require additional hydrogen and air sources, increasing system complexity. Simultaneously, existing detectors suffer from baseline drift during continuous detection, affecting the accuracy and repeatability of the results.

[0005] Regarding sample validity assessment, exhaled gas testing requires the sample to originate from deep alveoli to ensure the results accurately reflect the body's metabolic state. However, current analytical instruments lack effective mechanisms for determining sample origin, making it difficult to distinguish between alveolar gas and dead space gas in the oral cavity. This can lead to biased test results due to the quality of sample collection.

[0006] In terms of instrument management and maintenance, traditional gas chromatographs are mostly stand-alone devices that operate independently, lacking remote data management and calibration capabilities. When detector zero-point drift or range drift occurs, manual calibration by professional technicians is usually required on-site, resulting in high maintenance costs and slow response times. Furthermore, the detection data from each instrument are independent, making it difficult to achieve unified management and cross-sectional comparative analysis of data from multiple devices.

[0007] Furthermore, directly using ambient air as the carrier gas faces technical challenges. Ambient air contains moisture, and ordinary carbon molecular sieve stationary phase materials have strong hydrophilicity, easily adsorbing moisture and leading to a decrease in separation performance. At the same time, when using semiconductor or catalytic combustion sensors for detection, the sensor needs a certain baseline recovery time after the detection of the previous component is completed. If the chromatographic peak of the next component arrives before the sensor has recovered the baseline, it will cause detection interference or peak overlap.

[0008] Therefore, there is an urgent need to develop a gas chromatograph that can use air as a carrier gas, has sample validity determination function, and supports cloud data management and remote calibration, in order to meet the clinical needs for portability, accuracy and intelligent management in exhaled gas detection. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a gas chromatograph and gas component detection method based on cloud data management, which solves the technical problems of existing gas chromatographs, such as high operating costs due to reliance on high-purity inert carrier gas, difficulty in achieving both high and low detection sensitivity for hydrogen and methane, baseline drift, lack of sample source validity determination mechanism, and lack of remote data management and calibration functions.

[0010] This invention provides a gas chromatograph based on cloud data management, including an injection module, a separation module, a detection module, an analysis module, and a communication module.

[0011] The sample introduction module includes a gas path switching device and a quantitative gas storage component, used to automatically collect target gas samples through gas path switching and quantitatively introduce the target gas samples into the separation module. Specifically, the gas path switching device includes a gas pump and a solenoid valve assembly, and the quantitative gas storage component is a quantitative gas storage tube. In the sampling state, the gas pump and solenoid valve assembly are controlled to push the target gas sample to be tested into the quantitative gas storage tube through the sample inlet and fill it; in the sample introduction state, the solenoid valve assembly is controlled to switch channels, allowing air carrier gas to enter the quantitative gas storage tube, and pushing the target gas sample stored in the quantitative gas storage tube into the separation module. Through the above sample introduction logic, automatic quantitative collection and introduction of target gas samples are realized, ensuring the consistency of the sample volume each time.

[0012] The separation module is connected to the injection module via a gas path and includes a chromatographic separation column, a carrier gas control unit, and a separation optimization unit. The chromatographic separation column is filled with a hydrophobically modified stationary phase material to achieve chromatographic separation of hydrogen and methane components in the target gas sample under the propulsion of an air carrier gas. This invention uses ambient air as the carrier gas, and the carrier gas control unit controls the carrier gas flow rate from 10 mL / min to 50 mL / min, which reduces operating costs and avoids the gas source dependence problem of traditional inert carrier gases. In a preferred embodiment, the carrier gas is dried and filtered ambient air to further reduce the impact of moisture on the separation effect.

[0013] Furthermore, the hydrophobically modified stationary phase material is a carbon molecular sieve material with a hydrophobic carbon layer formed by chemical vapor deposition or a carbon molecular sieve material with a hydrophobic surface formed by polyphenylene ether coating. The hydrophobic modification treatment effectively reduces the adsorption capacity of the stationary phase material for moisture, avoiding interference from water vapor in exhaled gas on the separation effect, and ensuring good hydrogen and methane separation even under air carrier gas conditions. The particle size of the hydrophobically modified stationary phase material is 150 μm to 250 μm, the inner diameter of the chromatographic separation column is 1 mm to 3 mm, and the length is 0.5 m to 1.5 m. These parameter ranges have been optimized to shorten the analysis time while ensuring separation accuracy.

[0014] The separation optimization unit is used to obtain the retention time difference T1 between methane and hydrogen components through the chromatographic separation column and the baseline recovery time T2 of the hydrogen-methane composite sensor. By adjusting the carrier gas flow rate and / or column temperature, T1 and T2 are kept within the range of 3 seconds ≤ T1 - T2 ≤ 8 seconds. This design ensures that the next component arrives at the detector only after the previous component has been detected and the sensor baseline has recovered, thus avoiding overlapping interference from adjacent chromatographic peaks and improving detection accuracy.

[0015] The detection module includes a carbon dioxide sensor and a hydrogen and methane composite sensor. The hydrogen and methane composite sensor is located downstream of the chromatographic separation column and is used to detect the separated hydrogen and methane components, outputting a time-response signal as detection data. The carbon dioxide sensor is used to detect the carbon dioxide concentration of the target gas sample to determine the sample validity.

[0016] Furthermore, the carbon dioxide sensor is positioned upstream or downstream of the chromatographic separation column. When the carbon dioxide concentration detected by the sensor is within the range of 3.5% to 5.5%, the sample is deemed valid and the quantitative calculation process is triggered; when the carbon dioxide concentration is below 3.5%, the sample is deemed invalid and the current detection process is terminated or the data is marked as invalid; when the carbon dioxide concentration is above 5.5%, the sample can be marked as an abnormally valid sample and a notification will be displayed in the report. This sample validity determination mechanism effectively eliminates the deviation in detection results caused by the collection of dead space air in the oral cavity, thus improving the reliability of the detection results.

[0017] Furthermore, the detection module also includes a signal acquisition unit, a pulse heating control unit, and a drift compensation unit. The signal acquisition unit acquires the time-response signals from the carbon dioxide sensor and the hydrogen-methane composite sensor. The pulse heating control unit performs pulse heating on the hydrogen-methane composite sensor to accelerate baseline recovery after the first response peak signal recedes and before the second response peak signal arrives, wherein the pulse heating temperature is 350°C to 450°C, and the heating duration is 0.5 seconds to 2 seconds. The drift compensation unit compensates for zero-point drift and / or range drift, providing drift compensation data support for the analysis module to perform calibration based on calibration parameters, ensuring the long-term stability of the detection data.

[0018] The analysis module is connected to the detection module and includes a peak identification submodule, a peak assignment submodule, a peak overlap processing submodule, a quantitative calculation submodule, and a report generation submodule. The peak identification submodule identifies the first and second response peaks from the time-response signal. The peak assignment submodule determines the assignment of the hydrogen and methane peaks when the peak position time difference between the first and second response peaks falls within a preset hysteresis time window set based on the baseline recovery time of the hydrogen and methane composite sensor. The peak overlap processing submodule performs peak shape deconvolution processing when the first and second response peaks overlap. The quantitative calculation submodule calculates the hydrogen and methane concentrations based on peak area and / or peak height combined with pre-stored calibration curves. The report generation submodule generates an analysis report including hydrogen concentration, methane concentration, and sample validity markers.

[0019] The communication module connects to the analysis module and a cloud server to upload analysis reports and / or test data, and to receive drift compensation parameters from the cloud server to update calibration parameters. Specifically, the data uploaded by the communication module includes test data, ambient temperature, and baseline voltage; the test data includes the peak-to-peak values ​​of the first and second responses extracted from the time-response signal. The cloud server performs statistical analysis based on historical test data from multiple instruments of the same model to generate and distribute drift compensation parameters, including zero-point drift compensation coefficients and range drift compensation coefficients. Through cloud-based data management and remote calibration mechanisms, unified management and automated drift compensation calibration of multiple instruments are achieved, reducing on-site maintenance costs.

[0020] The present invention also provides a method for detecting gas components, performed using the above-mentioned gas chromatograph, comprising the following steps: S1. Collection and Injection: The target gas sample is automatically collected through the gas path switching device and quantitative gas storage component, and the target gas sample is introduced into the chromatographic separation column using air carrier gas.

[0021] S2. Component separation: Air carrier gas is introduced to propel the target gas sample through a chromatographic separation column filled with hydrophobic modified stationary phase material, thereby achieving chromatographic separation of hydrogen components and methane components.

[0022] S3. Validity determination and detection: The carbon dioxide concentration is detected upstream or downstream of the chromatographic separation column and the validity of the sample is determined. When the sample is valid, the time-response signal of the hydrogen and methane composite sensor is collected, and pulse heating is performed after the first response peak signal falls and before the second response peak signal arrives to accelerate baseline recovery.

[0023] S4. Calibration and Analysis: Based on the calibration parameters, the detection data is calibrated to compensate for drift. Peak identification, peak assignment and concentration calculation are performed on the calibrated detection data, and an analysis report is generated.

[0024] S5. Cloud Interaction: Upload analysis reports and / or detection data to the cloud server, and receive drift compensation parameters from the cloud server to update calibration parameters.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses ambient air as the carrier gas, preferably dried and filtered ambient air, combined with hydrophobic modified carbon molecular sieve stationary phase material, which eliminates the dependence on high-purity inert gas and significantly reduces the cost of use; at the same time, a carbon dioxide sensor is set in the detection module for sample validity determination, effectively distinguishing between deep alveolar gas and dead space gas in the oral cavity, thus improving the clinical reliability of the detection results.

[0026] 2. This invention adjusts the carrier gas flow rate and / or column temperature through a separation optimization unit to ensure that the retention time difference T1 and the baseline recovery time T2 satisfy 3 seconds ≤ T1 - T2 ≤ 8 seconds. Pulse heating is performed after the first response peak recedes and before the second response peak arrives to accelerate baseline recovery, effectively avoiding the overlapping interference of adjacent chromatographic peaks and improving the accuracy of quantitative analysis.

[0027] 3. This invention establishes a connection with a cloud server through a communication module, enabling cloud uploading of detection data and unified management of multiple devices. The cloud server generates drift compensation parameters based on historical data statistical analysis of multiple instruments and distributes them, realizing automated remote calibration, reducing on-site maintenance costs, and improving the level of intelligence in instrument management. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the gas chromatography analyzer system structure based on cloud data management according to the present invention; Figure 2 This is a schematic diagram of the sample introduction module structure of the present invention; Figure 3 This is a schematic diagram of the detection module structure of the present invention; Figure 4 This is a schematic diagram of the overall structure of the detection module of the present invention; Figure 5 This is a schematic diagram of the analysis module structure of the present invention; Figure 6 This is a schematic diagram of the separate module structure of the present invention; Figure 7 This is a flowchart of the gas component detection method of the present invention.

[0029] Reference numerals: 100, Sample injection module; 110, Gas pump; 121, First solenoid valve; 122, Second solenoid valve; 123, Third solenoid valve; 130, Quantitative gas storage tube; 200. Separation module; 210. Carrier gas control unit; 220. Separation optimization unit; 300. Detection module; 310. Carbon dioxide sensor; 320. Hydrogen and methane composite sensor; 330. Signal acquisition unit; 340. Pulse heating control unit; 350. Drift compensation unit; 400. Analysis Module; 410. Peak Identification Submodule; 420. Peak Assignment Submodule; 430. Peak Overlap Processing Submodule; 441. Quantitative Calculation Submodule; 450. Report Generation Submodule; 500. Communication module. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] To address the technical problems of existing gas chromatographs, such as high operating costs due to reliance on high-purity inert carrier gas, difficulty in achieving balanced detection sensitivity for both hydrogen and methane with baseline drift, lack of sample source validity determination mechanism, and lack of remote data management and calibration functions, this invention provides a cloud-based gas chromatograph and gas component detection method.

[0032] like Figure 1 As shown, the present invention provides a gas chromatograph based on cloud data management, including an injection module 100, a separation module 200, a detection module 300, an analysis module 400, and a communication module 500.

[0033] The sample introduction module 100 includes a gas path switching device and a quantitative gas storage component, which is used to automatically collect target gas samples through gas path switching and quantitatively introduce the target gas samples into the separation module 200.

[0034] The separation module 200 is connected to the injection module 100 via a gas path and includes a chromatographic separation column. The chromatographic separation column is filled with a hydrophobic modified stationary phase material, which is used to achieve chromatographic separation of hydrogen and methane components in the target gas sample under the impetus of air carrier gas.

[0035] The detection module 300 includes a carbon dioxide sensor 310 and a hydrogen and methane composite sensor 320. The hydrogen and methane composite sensor 320 is located downstream of the chromatographic separation column and is used to detect the separated hydrogen and methane components and output a time-response signal; the carbon dioxide sensor 310 is used to detect the carbon dioxide concentration of the target gas sample to determine the sample validity.

[0036] The analysis module 400 is connected to the detection module 300 and is used to perform peak identification, peak attribution and quantitative calculation on the detection data, and generate an analysis report.

[0037] The communication module 500 is connected to the analysis module 400 and communicates with the cloud server to upload analysis reports and / or detection data, and to receive drift compensation parameters from the cloud server to update calibration parameters.

[0038] The working principle of the above technical solution is as follows: First, the target gas sample is automatically collected and quantitatively injected through the injection module 100; second, the separation module 200 realizes the chromatographic separation of hydrogen and methane under the impetus of air carrier gas; then, the validity of the sample is determined based on the carbon dioxide sensor in the detection module 300, and the separated gas components are detected by the hydrogen and methane composite sensor 320; next, the analysis module 400 performs peak identification and quantitative calculation on the detection data; finally, the communication module 500 realizes the cloud upload of the detection data and the remote update of the drift compensation parameters.

[0039] The beneficial effects of the above technical solution are: it achieves effective separation of hydrogen and methane under air carrier gas conditions, and improves detection reliability and maintenance convenience through sample validity determination and cloud data management.

[0040] In one embodiment, such as Figure 3 As shown, in the detection module 300, the carbon dioxide sensor 310 is set upstream or downstream of the chromatographic separation column to detect the carbon dioxide concentration of the target gas sample to determine the sample validity; the hydrogen and methane composite sensor 320 is set downstream of the chromatographic separation column to output the first response peak and the second response peak corresponding to the hydrogen component and the methane component.

[0041] In this embodiment, the carbon dioxide sensor 310 is preferably a non-dispersive infrared sensor with a detection range of 0% to 10% and a resolution of not less than 0.1%. The hydrogen and methane composite sensor 320 is preferably a semiconductor gas sensor or a catalytic combustion sensor with a detection range of 0 ppm to 200 ppm for hydrogen and 0 ppm to 100 ppm for methane.

[0042] The beneficial effects of the above technical solution are as follows: by setting up a carbon dioxide sensor 310 to determine the validity of the sample, it is possible to effectively distinguish between deep alveolar gas and dead space gas in the oral cavity, ensuring the clinical reliability of the test results; the hydrogen and methane composite sensor 320 can respond to the two components after chromatographic separation, meeting the sensitivity requirements of clinical testing.

[0043] In one embodiment, the gas path switching device of the sample injection module 100 includes a gas pump 110 and a solenoid valve group, wherein the solenoid valve group specifically includes a first solenoid valve 121, a second solenoid valve 122 and a third solenoid valve 123; the quantitative gas storage component is a quantitative gas storage tube 130.

[0044] like Figure 2As shown, the sample introduction module 100 is used to execute the following sample introduction logic: In the sampling state, the first solenoid valve 121 is opened, the second solenoid valve 122 is closed, and the third solenoid valve 123 is opened, the gas pump 110 works, and the target gas sample to be tested is pushed into the quantitative gas storage tube 130 through the sample introduction port and fills it; In the sample introduction state, the first solenoid valve 121 is closed, the second solenoid valve 122 is opened, and the third solenoid valve 123 is closed, the air carrier gas enters the quantitative gas storage tube 130 through the second solenoid valve 122, and pushes the target gas sample stored in the quantitative gas storage tube 130 into the separation module 200.

[0045] In this embodiment, the volume of the quantitative gas storage tube 130 is 1 mL to 10 mL, preferably 5 mL, to meet the sample volume requirements for exhaled gas detection. The flow rate of the gas pump 110 is 50 mL / min to 200 mL / min, and the sampling time is 5 seconds to 30 seconds.

[0046] The beneficial effects of the above technical solution are as follows: by cooperating with the gas path switching device and the quantitative gas storage component, the automatic quantitative collection and injection of the target gas sample is realized, ensuring the consistency of the injection volume each time, reducing human operation error, and improving the repeatability of the detection results.

[0047] In one embodiment, such as Figure 6 As shown, the separation module 200 also includes a carrier gas control unit 210 and a separation optimization unit 220.

[0048] The carrier gas control unit 210 provides ambient air as the carrier gas and controls the carrier gas flow rate to be between 10 mL / min and 50 mL / min. In a preferred embodiment, the carrier gas control unit 210 provides dried and filtered ambient air as the carrier gas. In this embodiment, the carrier gas control unit 210 includes an air inlet, a drying filter, a flow control valve, and a flow sensor. The drying filter is filled with molecular sieve desiccant and activated carbon to remove moisture and impurities from the ambient air.

[0049] The separation optimization unit 220 is used to obtain the retention time difference T1 between the methane component and the hydrogen component through the chromatographic separation column and the baseline recovery time T2 of the hydrogen and methane composite sensor 320, and to adjust the carrier gas flow rate and / or column temperature to make T1 and T2 satisfy 3 seconds ≤ T1-T2 ≤ 8 seconds.

[0050] In this embodiment, under the conditions of a carrier gas flow rate of 20 mL / min and a column temperature of 50 °C, the retention time of the hydrogen component is about 15 seconds, the retention time of the methane component is about 25 seconds, and the retention time difference T1 is about 10 seconds; the baseline recovery time T2 of the hydrogen and methane composite sensor 320 is about 3 to 5 seconds, which satisfies the condition 3 seconds ≤ T1 - T2 ≤ 8 seconds, ensuring that the detection of the two components does not overlap or interfere.

[0051] The beneficial effects of the above technical solution are as follows: the coordinated cooperation between the carrier gas control unit 210 and the separation optimization unit 220 further enhances the feasibility of the low-cost carrier gas solution; by setting a hysteresis time window, it ensures that the detection of adjacent components does not overlap, thereby improving the accuracy of quantitative analysis.

[0052] In one embodiment, the hydrophobically modified stationary phase material is a carbon molecular sieve material with a hydrophobic carbon layer formed by chemical vapor deposition or a carbon molecular sieve material with a hydrophobic surface formed by polyphenylene ether coating.

[0053] In this embodiment, the process parameters for preparing the hydrophobic carbon layer by chemical vapor deposition are as follows: methane or acetylene is used as the carbon source gas, the deposition temperature is 600°C to 800°C, the deposition time is 1 hour to 4 hours, and a hydrophobic carbon layer with a thickness of 10 nm to 100 nm is formed. The process parameters for the polyphenylene ether coating treatment are as follows: carbon molecular sieves are immersed in a polyphenylene ether solution with a mass fraction of 1% to 5% for 1 hour to 4 hours, and then dried at 100°C to 150°C for 2 hours to 4 hours.

[0054] The hydrophobically modified stationary phase material has a particle size of 150 μm to 250 μm; the chromatographic separation column has an inner diameter of 1 mm to 3 mm, preferably 2 mm; and a length of 0.5 m to 1.5 m, preferably 1 m.

[0055] The beneficial effects of the above technical solution are as follows: the hydrophobic modification treatment effectively reduces the adsorption capacity of the stationary phase material for water, avoids the interference of water vapor in exhaled gas on the separation effect, and ensures that good hydrogen and methane separation effect can still be obtained under air carrier gas conditions.

[0056] In one embodiment, such as Figure 4 As shown, the detection module 300 also includes a signal acquisition unit 330, a pulse heating control unit 340, and a drift compensation unit 350.

[0057] The signal acquisition unit 330 is used to acquire the time-response signals of the carbon dioxide sensor 310 and the hydrogen and methane composite sensor 320. In this embodiment, the sampling frequency of the signal acquisition unit 330 is 10Hz to 100Hz, and the sampling accuracy is 12 bits to 16 bits.

[0058] The pulse heating control unit 340 is used to perform pulse heating on the hydrogen and methane composite sensor 320 to accelerate baseline recovery after the first response peak signal has fallen and before the second response peak signal arrives, wherein the pulse heating temperature is 350°C to 450°C and the heating duration is 0.5 seconds to 2 seconds.

[0059] In this embodiment, the trigger condition for pulse heating is as follows: after detecting the peak value of the first response, pulse heating is triggered when the signal drops to below 20% of the peak value. Pulse heating is achieved by applying a short-term high-power current to the sensor heating wire, with a heating power of 0.5W to 2W.

[0060] The drift compensation unit 350 is used to acquire the compensation amount for zero-point drift and / or range drift, and transmit the compensation amount to the analysis module 400, which then performs calibration of the detection data based on the calibration parameters. In this embodiment, the zero-point drift compensation uses the following formula: Vcalibration = Vmeasurement - Vzero offset; Range drift compensation uses the following formula: C calibration = C measurement × K range, where K range is the range drift compensation coefficient.

[0061] The beneficial effects of the above technical solution are as follows: by controlling pulse heating, residual adsorbents on the sensor surface can be quickly removed without affecting subsequent component detection, thus shortening the baseline recovery time and improving detection efficiency; and by using drift compensation calibration, the long-term stability of detection data can be ensured.

[0062] In one embodiment, the sample validity determination includes: when the carbon dioxide concentration detected by the carbon dioxide sensor 310 is in the range of 3.5% to 5.5%, the sample is determined to be valid and the quantitative calculation process is triggered; when the carbon dioxide concentration is below 3.5%, the sample is determined to be invalid and the current detection process is terminated or the data is marked as invalid; when the carbon dioxide concentration is above 5.5%, the sample can be marked as an abnormally valid sample and a notification is given in the report.

[0063] In this embodiment, the carbon dioxide concentration in the deep alveolar gas exhaled by the human body is typically in the range of 3.5% to 5.5%, while the dead space gas in the oral cavity mainly consists of the ambient air inhaled previously, and its carbon dioxide concentration is close to atmospheric levels (approximately 0.04%), significantly lower than that of the alveolar gas. Therefore, detecting the carbon dioxide concentration can effectively determine whether the collected gas sample originates from the deep alveoli.

[0064] Furthermore, when the carbon dioxide concentration detected by the carbon dioxide sensor 310 exceeds 5.5%, the system can mark the sample as an abnormal valid sample and indicate this in the analysis report. Possible reasons for this include: excessive effort at the end of exhalation leading to excessive alveolar gas expulsion, sensor calibration deviation, or individual physiological differences. The hydrogen and methane detection data for such abnormal valid samples are still recorded and calculated, but clinicians are advised to consider the subject's condition when making a comprehensive assessment of the reliability of the test results.

[0065] The beneficial effects of the above technical solution are as follows: by setting the effective range and abnormal range of carbon dioxide concentration, a complete sample quality grading and judgment mechanism is established, which eliminates the deviation of test results caused by poor sample collection quality from the source.

[0066] In one embodiment, such as Figure 5 As shown, the analysis module 400 includes a peak identification submodule 410, a peak assignment submodule 420, a peak overlap processing submodule 430, a quantitative calculation submodule 440, and a report generation submodule 450.

[0067] The peak identification submodule 410 is used to identify the first response peak and the second response peak from the time-response signal. In this embodiment, the peak identification adopts the first derivative zero-crossing point method or the second derivative extremum point method, and the peak identification threshold is set to 3 to 5 times the baseline noise.

[0068] The peak assignment submodule 420 is used to determine the assignment of the hydrogen peak and the methane peak when the peak position time difference between the first response peak and the second response peak falls within a preset hysteresis time window set based on the baseline recovery time of the hydrogen and methane composite sensor 320. In this embodiment, because hydrogen has a small molecular weight and weak interaction with the stationary phase, its retention time is shorter than that of methane. The system confirms the peak assignment by combining the preset hysteresis time window. When the peak position time difference between the first response peak and the second response peak falls within the range of this window, it is confirmed that the first peak is the hydrogen peak and the second peak is the methane peak.

[0069] The peak overlap processing submodule 430 is used to perform peak shape deconvolution processing when the first response peak and the second response peak overlap. In this embodiment, peak shape deconvolution adopts Gaussian fitting method or exponentially modified Gaussian fitting method to decompose the overlapping peak into independent component peaks and calculate the peak area of ​​each component.

[0070] The quantitative calculation submodule 440 is used to calculate hydrogen and methane concentrations based on peak area and / or peak height combined with pre-stored calibration curves. In this embodiment, the calibration curves are established using a multi-point calibration method, with no fewer than 5 calibration points, and a linear correlation coefficient R0. 2 Not less than 0.995.

[0071] The report generation submodule 450 is used to generate an analytical report that includes hydrogen concentration, methane concentration, and sample validity markers. In this embodiment, the analytical report may also include auxiliary information such as detection time, ambient temperature, and baseline voltage.

[0072] In one embodiment, the analysis module 400 receives the drift compensation amount provided by the drift compensation unit 350, calibrates the detection data based on the calibration parameters, and then performs peak identification and quantitative calculation.

[0073] The beneficial effects of the above technical solution are as follows: through a complete process of peak identification, peak assignment, peak overlap processing and quantitative calculation, accurate quantitative results can be obtained under various detection conditions; the analysis report format is standardized, making it easy for clinicians to directly read and interpret the test results.

[0074] In one embodiment, the data uploaded by the communication module 500 includes detection data, ambient temperature, and baseline voltage; wherein the detection data includes the peak-to-peak value of the first response and the peak-to-peak value of the second response extracted from the time-response signal; the cloud server performs statistical analysis based on historical detection data from multiple instruments of the same model to generate drift compensation parameters, which include zero-point drift compensation coefficient and range drift compensation coefficient.

[0075] In this embodiment, the communication module 500 establishes a connection with the cloud server via wireless communication, supporting communication protocols such as WiFi, 4G / 5G cellular networks, or Bluetooth. The upload cycle of the detection data can be set to upload immediately after each detection or upload in batches at set time intervals.

[0076] After receiving test data uploaded by multiple instruments of the same model, the cloud server uses statistical process control methods to analyze the drift trend of each instrument. When the baseline voltage or peak response of an instrument deviates from the statistical mean of the same batch of instruments by more than a preset threshold, the cloud server calculates the drift compensation parameters for that instrument and sends an update.

[0077] The beneficial effects of the above technical solution are as follows: based on the statistical analysis of historical data from multiple instruments, drift compensation parameters are generated, which realizes horizontal comparison and automated calibration, extends the instrument calibration cycle, and improves the level of intelligence in equipment cluster management.

[0078] This invention also provides a method for detecting gas components, performed using the aforementioned gas chromatograph, such as... Figure 7 As shown, it includes the following steps: Step S1, Collection and Injection: The target gas sample is automatically collected through the gas path switching device and the quantitative gas storage component, and the target gas sample is introduced into the chromatographic separation column using air carrier gas.

[0079] In this step, the subject exhales into the injection port, and the air pump 110 starts to push the exhaled gas into the quantitative gas storage tube 130. After the quantitative gas storage tube 130 is full, the solenoid valve group switches channels, and the air carrier gas pushes the gas sample in the quantitative gas storage tube 130 into the chromatographic separation column.

[0080] Step S2, Component Separation: Air carrier gas is introduced to propel the target gas sample through a chromatographic separation column filled with hydrophobic modified stationary phase material, thereby achieving chromatographic separation of hydrogen components and methane components.

[0081] In this step, the components in the target gas sample are distributed between the stationary and mobile phases. Due to the different adsorption capacities of hydrogen and methane on the hydrophobically modified carbon molecular sieve, their retention times differ, thus achieving chromatographic separation. The hydrogen component elutes from the column before the methane component.

[0082] Step S3, Validity Determination and Detection: The carbon dioxide concentration is detected upstream or downstream of the chromatographic separation column and the sample validity is determined. When the sample is valid, the time-response signal of the hydrogen and methane composite sensor 320 is collected, and pulse heating is performed after the first response peak signal falls and before the second response peak signal arrives to accelerate baseline recovery.

[0083] In this step, the carbon dioxide concentration of the target gas sample is first detected by the carbon dioxide sensor 310. If the carbon dioxide concentration is within the range of 3.5% to 5.5%, the sample is considered valid, and the detection of hydrogen and methane continues. If the carbon dioxide concentration is below 3.5%, the sample is considered invalid. In this case, the system can terminate the current detection process and prompt the subject to resample, or continue the detection process but mark the data as invalid for subsequent analysis. When the sample is valid, the hydrogen and methane composite sensor 320 sequentially detects the hydrogen and methane components eluting from the chromatographic column, outputting the corresponding first and second response peaks. After the first response peak recedes and before the second response peak arrives, the sensor is pulse-heated to accelerate baseline recovery, creating conditions for accurate detection of the second response peak.

[0084] Step S4, Calibration and Analysis: Based on the calibration parameters, perform drift compensation calibration on the detection data, identify peaks, assign peaks, and calculate concentrations on the calibrated detection data, and generate an analysis report.

[0085] In this step, the drift compensation unit 350 performs zero-point drift and range drift compensation on the detection data according to the drift compensation parameters sent from the cloud; the analysis module 400 identifies the peaks of the calibrated time-response signal, determines the position and area of ​​the first and second response peaks; assigns peaks based on peak position and time, and determines the hydrogen peak and methane peak; calculates the hydrogen concentration and methane concentration by combining the pre-stored calibration curve; and finally generates an analysis report containing hydrogen concentration, methane concentration, and sample validity label.

[0086] Step S5, Cloud Interaction: Upload the analysis report and / or detection data to the cloud server, and receive the drift compensation parameters sent by the cloud server to update the calibration parameters.

[0087] In this step, the communication module 500 uploads the analysis report and raw test data of this test to the cloud server for storage and statistical analysis; at the same time, it checks whether there are updated drift compensation parameters on the cloud server. If so, it downloads and updates the local calibration parameters to ensure the accuracy of subsequent tests.

[0088] The beneficial effects of the above method are as follows: through automated sample collection, validity determination, drift compensation calibration and cloud data management, accurate and rapid detection of hydrogen and methane concentrations in exhaled gas is achieved. The entire detection process requires no manual intervention, is easy to operate, and the detection results are reliable.

[0089] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gas chromatograph based on cloud data management, characterized in that, include: The sample introduction module includes a gas path switching device and a quantitative gas storage component, which is used to automatically collect target gas samples through gas path switching and quantitatively introduce the target gas samples into the separation module; The separation module, connected to the gas path of the injection module, includes a chromatographic separation column filled with a hydrophobic modified stationary phase material, used to achieve chromatographic separation of hydrogen and methane components in the target gas sample under the impetus of air carrier gas; The detection module includes a carbon dioxide sensor and a hydrogen and methane composite sensor. The hydrogen and methane composite sensor is located downstream of the chromatographic separation column and is used to detect the separated hydrogen and methane components and output a time-response signal as detection data. The carbon dioxide sensor is used to detect the carbon dioxide concentration of the target gas sample to determine the sample validity. The analysis module, connected to the detection module, is used to calibrate the detection data based on calibration parameters, and to perform peak identification, peak attribution and quantitative calculation on the calibrated detection data to generate an analysis report; The communication module is connected to the analysis module and communicates with the cloud server to upload the analysis report and / or detection data, and to receive drift compensation parameters from the cloud server to update the calibration parameters.

2. The gas chromatograph according to claim 1, characterized in that, The carbon dioxide sensor is positioned upstream or downstream of the chromatographic separation column; the hydrogen and methane composite sensor is used to output the first and second response peaks corresponding to the hydrogen and methane components.

3. The gas chromatograph according to claim 1, characterized in that, The gas path switching device includes a gas pump and a solenoid valve assembly; the quantitative gas storage component is a quantitative gas storage tube; the sample injection module is used to execute the following sample injection logic: During sampling, the gas pump and solenoid valve group are controlled to push the target gas sample into the quantitative gas storage tube through the inlet. During sample introduction, the control solenoid valve group switches channels to allow air carrier gas to enter the quantitative gas storage tube, pushing the target gas sample stored in the quantitative gas storage tube into the separation module.

4. The gas chromatograph according to claim 1, characterized in that, The separation module further includes: The carrier gas control unit is used to provide dried and filtered ambient air as carrier gas and control the carrier gas flow rate from 10 mL / min to 50 mL / min. The separation optimization unit is used to obtain the retention time difference T1 between methane and hydrogen components through the chromatographic separation column and the baseline recovery time T2 of the hydrogen and methane composite sensor, and to adjust the carrier gas flow rate and / or column temperature to make T1 and T2 satisfy 3 seconds ≤ T1-T2 ≤ 8 seconds.

5. The gas chromatograph according to claim 1, characterized in that, The hydrophobic modified stationary phase material is a carbon molecular sieve material with a hydrophobic carbon layer formed by chemical vapor deposition or a carbon molecular sieve material with a hydrophobic surface formed by polyphenylene ether coating treatment; the particle size of the hydrophobic modified stationary phase material is 150μm to 250μm; the inner diameter of the chromatographic separation column is 1mm to 3mm and the length is 0.5m to 1.5m.

6. The gas chromatograph according to claim 2, characterized in that, The detection module also includes: The signal acquisition unit is used to acquire the time-response signals of the carbon dioxide sensor and the hydrogen and methane composite sensor. A pulse heating control unit is used to perform pulse heating on the hydrogen and methane composite sensor to accelerate baseline recovery after the first response peak signal recedes and before the second response peak signal arrives, wherein the pulse heating temperature is 350°C to 450°C and the heating duration is 0.5 seconds to 2 seconds. A drift compensation unit is used to compensate for zero drift and / or range drift based on calibration parameters.

7. The gas chromatograph according to claim 2, characterized in that, The sample validity determination includes: when the carbon dioxide concentration detected by the carbon dioxide sensor is in the range of 3.5% to 5.5%, the sample is determined to be valid and the quantitative calculation process is triggered; when the carbon dioxide concentration is lower than 3.5%, the sample is determined to be invalid and the current detection process is terminated or the data is marked as invalid; when the carbon dioxide concentration is higher than 5.5%, the sample can be marked as an abnormally valid sample and a notification is given in the report.

8. The gas chromatograph according to claim 1, characterized in that, The analysis module includes: A peak identification submodule is used to identify a first response peak and a second response peak from the time-response signal; The peak attribution submodule is used to determine the attribution of the hydrogen peak and the methane peak when the peak position time difference between the first response peak and the second response peak meets the preset hysteresis time window. The preset hysteresis time window is set based on the baseline recovery time of the hydrogen and methane composite sensor. The baseline recovery time is a pre-stored parameter or is determined by the system in real time based on the fall process of the first response peak. The peak overlap processing submodule is used to perform peak shape deconvolution processing when the first response peak and the second response peak overlap. The quantitative calculation submodule is used to calculate hydrogen and methane concentrations based on peak area and / or peak height combined with pre-stored calibration curves. The report generation submodule is used to generate analytical reports that include hydrogen concentration, methane concentration, and sample validity markers.

9. The gas chromatograph according to claim 1, characterized in that, The data uploaded by the communication module includes the detection data, ambient temperature, and baseline voltage; wherein the detection data includes the first response peak-to-peak value and the second response peak-to-peak value extracted from the time-response signal; the cloud server generates the drift compensation parameters based on statistical analysis of historical detection data from multiple instruments of the same model, and the drift compensation parameters include the zero-point drift compensation coefficient and the range drift compensation coefficient.

10. A method for detecting gas components, characterized in that, The method, performed using a gas chromatograph according to any one of claims 1 to 9, comprises the following steps: S1. Collection and injection: The target gas sample is automatically collected through the gas path switching device and the quantitative gas storage component, and the target gas sample is introduced into the chromatographic separation column using air carrier gas; S2, Component separation: Air carrier gas is introduced to push the target gas sample through a chromatographic separation column filled with hydrophobic modified stationary phase material to achieve chromatographic separation of hydrogen component and methane component; S3. Validity determination and detection: The carbon dioxide concentration is detected upstream or downstream of the chromatographic separation column and the validity of the sample is determined. When the sample is valid, the time-response signal of the hydrogen and methane composite sensor is collected, and pulse heating is performed after the first response peak signal falls and before the second response peak signal arrives to accelerate baseline recovery. S4. Calibration and Analysis: Based on the calibration parameters, the detection data is calibrated to compensate for drift. Peak identification, peak assignment and concentration calculation are performed on the calibrated detection data, and an analysis report is generated. S5. Cloud Interaction: Upload the analysis report and / or detection data to the cloud server, and receive drift compensation parameters from the cloud server to update the calibration parameters.

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