Low-heat-capacity chromatographic column module capable of cooling

Abstract

The utility model relates to a cooling low heat capacity chromatographic column module, which comprises a box body and a refrigeration part connected with the box body, the refrigeration part is a sandwich structure formed by a semiconductor refrigeration sheet, heat dissipation fins and cold storage fins, the hot end of the semiconductor refrigeration sheet is connected with the heat dissipation fins, and the cold end of the semiconductor refrigeration sheet is connected with the cold storage fins. One end of the box body is connected and sealed through a box end cover, a low-heat-capacity chromatographic column is arranged in the box body, and the refrigeration part is connected with the box end cover through a cold accumulation fin. According to the utility model, the cooling speed is higher, the environmental adaptability is strong, the temperature can still be reduced to the initial temperature outdoors even in hot summer, and the temperature of the module can be rapidly reduced to 50 DEG C from 200 DEG C after the temperature programming is finished. Besides, the cooling time can be shortened by 50%, and the total time of the analysis process of the portable chromatograph-mass spectrometer can be greatly shortened, so that the analysis efficiency is improved, the separation degree of low-boiling-point substances can be greatly improved, and meanwhile, the analysis sensitivity of the low-boiling-point substances is also improved.

Description

Technical Field

[0001] The utility model relates to the technical field of chromatographic columns in chromatographic mass spectrometric analysis instruments, in particular to a low-heat-capacity chromatographic column module capable of being cooled. Background Art

[0002] Desktop gas chromatographs cool the entire column box by changing the ambient temperature of the instrument or using liquid carbon dioxide. However, portable gas chromatograph-mass spectrometers are limited by the instrument's own size, weight, and operating environment. They generally do not use a column oven design, and generally use low thermal mass columns and heating technology. In other words, the heating wire, insulating material, temperature measuring element, and chromatographic column are directly wound together through a specific process. Portable gas chromatograph-mass spectrometers are mainly used for emergency measurements, and are mostly used outdoors or in more complex environments. They cannot carry large amounts of refrigerants or use compression refrigeration equipment. Therefore, the cooling of the chromatographic column is mainly achieved by using a fan to force convection between the ambient air and the air in the chromatographic column module, so that the air removes the heat from the chromatographic column to achieve the purpose of cooling the chromatographic column.

[0003] The disadvantage of this cooling method is that the lowest temperature the column can reach is limited by the ambient temperature. In summer or in areas with high ambient temperatures, the column's initial temperature cannot reach a low enough level. Therefore, portable gas chromatograph-mass spectrometers currently on the market typically set the initial temperature of the column programming to 50°C or above to accommodate most analytical environments. Although this setting has little effect on the analysis and detection of high-boiling-point organic compounds, a higher initial column temperature can significantly adversely affect the analysis when the analyte contains multiple low-boiling-point organic compounds. If the initial column temperature is too high, the low-boiling-point organic compounds in the sample will vaporize and diffuse rapidly, eluting from the column. This manifests itself on the chromatogram as the peaks of the low-boiling-point organic compounds crowding the front of the chromatogram, forming wide, overlapping peak bands. This can lead to a decrease in separation and analytical sensitivity, severely affecting the qualitative and quantitative results of low-boiling-point compounds. Although mass spectrometry deconvolution can reconstruct the mass spectrometry data of overlapping chromatographic peaks in the total ion current chromatogram to obtain a single chromatographic peak signal for the compound, good chromatographic separation conditions are still a prerequisite for improving the accuracy of mass spectrometry deconvolution results. Therefore, a low thermal mass column module with rapid cooling is urgently needed. Utility Model Content

[0004] The content of this utility model is used to briefly introduce the concepts that will be described in detail in the detailed description section below. The content of this utility model is not intended to identify the key features or essential features of the technical solution for which protection is sought, nor is it intended to limit the scope of the technical solution for which protection is sought.

[0005] To address the problems and shortcomings of the existing technology, the present invention aims to provide a low-heat-mass chromatography column module capable of cooling down. The module comprises a housing connected to a cooling unit, which comprises a sandwich structure consisting of heat sink fins, semiconductor cooling sheets, and cold storage fins. This structure offers low heat capacity, rapid cooling, and minimal impact from ambient operating temperature. It eliminates the need for additional refrigerants and improves the analytical sensitivity of analytical instruments, thereby resolving the issues raised in the background art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: it includes a box body and a refrigeration part connected thereto, the refrigeration part is a sandwich structure composed of a semiconductor refrigeration sheet, a heat dissipation fin and a cold storage fin, the hot end of the semiconductor refrigeration sheet is connected to the heat dissipation fin, and the cold end of the semiconductor refrigeration sheet is connected to the cold storage fin, one end of the box body is connected and sealed by a box end cover, and a low heat capacity chromatographic column is installed inside the box body, and the refrigeration part is connected to the box end cover through the cold storage fin.

[0007] Preferably, a cooling fan is connected below the end cap, which cooperates with a plurality of vents provided on the end cap. The end cap is connected to an open end of the box body to seal the box body containing the low heat mass chromatographic column. Here, a cooling fan is connected below the end cap, and a plurality of vents are provided above the end cap at corresponding positions. During use, air cooled by the refrigeration unit is drawn into the box body through the vents by the cooling fan, thereby cooling the low heat mass chromatographic column within the box body.

[0008] Preferably, a fixed bracket is provided on the inner sidewall of the box body to engage the low heat mass chromatography column. Since the low heat mass chromatography column is disposed within the box body, a fixed bracket is provided on the inner sidewall of the box body to enhance stability during use. The fixed bracket secures the position of the low heat mass chromatography column, preventing it from shaking during use, thereby improving stability and safety.

[0009] Preferably, the side of the box body is provided with a plurality of heat dissipation openings. The side of the box body is provided with a plurality of heat dissipation openings. During use, the air after heat exchange is discharged from the box body through the plurality of heat dissipation openings to the outside, so as to keep the temperature of the structure of the utility model stable within the working range.

[0010] Preferably, the cooling fins are smaller than the heat sink fins. A larger heat sink has a greater surface area, allowing it to absorb more heat while also conducting it more quickly. The cooling fins are smaller than the heat sink fins to accommodate the size of the cooling fan under the box's end cap, allowing them to better assist the fan in drawing cooled air into the box, achieving better heat dissipation.

[0011] Preferably, thermally conductive silicone grease is applied between the semiconductor refrigeration sheet and the heat sink fins and cold storage fins. Silicone grease is evenly applied between the semiconductor refrigeration sheet and the heat sink fins, and between the cold storage fins and the semiconductor refrigeration sheet. Silicone grease is refined using silicone oil as a base oil thickened with an inorganic thickener, and has excellent waterproof sealing, water resistance, and solvent resistance. At the same time, silicone grease also has excellent thermal conductivity and stability in use, and can replace air with low thermal conductivity to improve thermal conductivity. Therefore, it can effectively improve the thermal conductivity and heat dissipation capacity between the heat sink fins, cold storage fins, and the semiconductor refrigeration sheet.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] The present invention has a simple structure, is easy to use, and can quickly raise and lower temperatures. It can rapidly lower the temperature of a low-heat-mass chromatographic column without the need for additional refrigerant. The module primarily comprises a refrigeration unit comprised of heat sink fins, semiconductor refrigeration sheets, and cold storage fins, with the overall refrigeration unit forming a sandwich structure. The present invention is used as a key module in portable chromatograph-mass spectrometers and plays a decisive role in the performance of the entire instrument. Compared to conventional low-heat-mass chromatographic column modules, the present module has a faster cooling rate and greater environmental adaptability. Even in the hot summer outdoors, the module can be lowered to a starting temperature as low as 20°C. After the programmed temperature increase is complete, the module can quickly lower the temperature from 200°C to 50°C. Furthermore, the module's cooling time can be shortened by 50%, significantly reducing the overall analysis time of the portable chromatograph-mass spectrometer, thereby improving analytical efficiency. When the temperature of the low-heat-mass chromatographic column is lower than the initial starting temperature, the separation of low-boiling-point substances can be greatly improved, thereby increasing the analytical sensitivity of low-boiling-point substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 : It is a schematic diagram of the connection structure of the utility model;

[0015] Figure 2 : This is a schematic diagram of the explosion decomposition of the utility model;

[0016] Figure 3 : This is a comparison diagram of the total ion current chromatogram of the utility model and the traditional module;

[0017] Figure 4 : An enlarged view of a low-boiling point portion of the total ion current chromatograms of the present invention and the conventional module;

[0018] Figure 5 : Another partial enlarged view of the low boiling point of the total ion flow chromatogram of the utility model and the traditional module.

[0019] The markings in the figure are: 1. Heat dissipation fins; 2. Semiconductor refrigeration plate; 3. Cold storage fins; 4. Box end cover; 5. Cooling fan; 6. Low thermal mass chromatography column; 7. Fixed bracket; 8. Box body; 9. Heat dissipation port. DETAILED DESCRIPTION

[0020] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure.

[0021] It should also be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other. Example

[0022] This embodiment provides a low thermal mass chromatography column module capable of cooling, such as Figure 1-2 As shown: it includes a box body 8 and a refrigeration part connected thereto. The refrigeration part is a sandwich structure composed of a semiconductor refrigeration sheet 2, a heat dissipation fin 1 and a cold storage fin 3. The hot end of the semiconductor refrigeration sheet 2 is connected to the heat dissipation fin 1, and the cold end of the semiconductor refrigeration sheet 2 is connected to the cold storage fin 3. One end of the box body 8 is connected and sealed by a box end cover 4, and a low heat capacity chromatographic column 6 is installed inside the box body 8. The refrigeration part is connected to the box end cover 4 through the cold storage fin 3.

[0023] This embodiment also includes a cooling fan 5 connected to the bottom of the box end cover 4, which cooperates with the multiple vents opened on the box end cover 4, and multiple cooling vents 9 are opened on the side of the box body 8. Here, the cooling fan 5 is connected to the bottom of the box end cover 4, and vents are opened at corresponding positions above it. When in use, the air cooled by the refrigeration part is sucked into the box body 8 through the vents by the cooling fan 5, thereby cooling the low heat capacity chromatographic column 6 in the box body 8. The cooling vents 9 on the side of the box body 8 can discharge the air after heat exchange from the box body 8 through the cooling vents 9 to the outside, so as to keep the temperature of the structure of the utility model stable within the working range.

[0024] This embodiment also includes that a fixed bracket 7 is provided on the inner wall of the box body 8 to clamp the low heat capacity chromatographic column 6, thermal grease is applied between the semiconductor refrigeration sheet 2 and the heat dissipation fins 1 and the cold storage fins 3, and the volume of the cold storage fins 3 is smaller than the heat dissipation fins 1. By connecting and supporting the fixed bracket 7 on the inner wall of the box body 8, the low heat capacity chromatographic column 6 can be fixed in position by the fixed bracket 7 so that it is not easy to shake during use, thereby improving its stability and safety. Applying silicone grease evenly between the semiconductor refrigeration sheet 2 and the heat dissipation fins 1, and between the cold storage fins 3 and the semiconductor refrigeration sheet 2 can effectively improve the heat conduction and heat dissipation capabilities between the heat dissipation fins 1, the cold storage fins 3 and the semiconductor refrigeration sheet 2. By making the volume of the cold storage fins 3 smaller than the heat dissipation fins 1, it can better assist the cooling fan 5 to draw the cooled air into the box body, thereby achieving a better heat dissipation effect.

[0025] How to use this embodiment

[0026] The utility model comprises a housing 8, a low-heat-mass chromatography column 6, and a cooling unit. The cooling unit comprises a sandwich structure consisting of heat sink fins 1, a semiconductor cooling element 2, and cold storage fins 3. During installation, thermal grease is evenly applied to both ends of the semiconductor cooling element 2. The larger heat sink fins 1 are mounted on the hot end of the semiconductor cooling element 2, and the smaller cold storage fins 3 are mounted on the cold end of the semiconductor cooling element 2. In other words, the semiconductor cooling element 2 is positioned between the heat sink fins 1 and the cold storage fins 3. The two fins are then screwed together to complete the cooling unit. Because the semiconductor cooling element 2 utilizes a PN junction formed from a specific semiconductor material, it operates silently, has a simple structure, and is compact. It does not require a compressor or additional refrigerant, resulting in high self-cooling efficiency. When the N-type and P-type semiconductor materials of the semiconductor cooling element 2 are connected to form a galvanic pair, energy transfer occurs when a direct current is applied to this circuit. The junction where current flows from the N-type element to the P-type element absorbs heat, known as the cold end; the junction where current flows from the P-type element to the N-type element releases heat, known as the hot end. The amount of heat absorption and heat release is determined by the size of the current and the number of element pairs of semiconductor materials N and P.

[0027] One end of the box body 8 is connected and sealed via the box end cover 4. A cooling fan 5 is connected and installed below the box end cover 4, and multiple ventilation holes are opened on the box end cover 4. The air inlet direction of the utility model is toward the refrigeration unit, and the air outlet direction is toward the box body 8. The low thermal mass chromatography column 6 is arranged and installed inside the box body 8. Specifically, a fixing bracket 7 can be supported on the inner side wall of the box body 8, and the low thermal mass chromatography column 6 is securely installed inside the box body 8 via this fixing bracket 7. Finally, the refrigeration unit, the box end cover 4 equipped with the cooling fan 5, and the box body 8 are fixed together to complete the assembly of the module of the utility model.

[0028] The module of the present invention is installed in a portable chromatograph-mass spectrometer. During use, when the low heat mass chromatographic column needs to be lowered to a temperature lower than the ambient temperature of the instrument, the refrigeration part and the cooling fan 5 are turned on. The external ambient air passes through the heat sink fins 1 at the hot end, the semiconductor refrigeration plate 2, and the cold storage fins 3 at the cold end in sequence. After being cooled, the air is sucked into the interior of the box body 8, causing the low heat mass chromatographic column 6 to cool down as a whole. The air after heat exchange is then discharged from the box body 8 through the heat dissipation port 9. The current temperature is monitored by the temperature measuring element inside the low heat mass chromatographic column 6 in the portable chromatograph-mass spectrometer, and the cooling power of the semiconductor refrigeration plate 2 is adjusted through PID control to stabilize the temperature within the required target temperature. The heat emitted by the hot end of the semiconductor refrigeration plate 2 is transferred to the heat sink fins 1, and then the heat blown into the external ambient air is removed by the cooling fan 5, so that the temperature difference between the hot and cold ends is maintained at a relatively fixed level, thereby improving the working efficiency of the semiconductor refrigeration plate 2.

[0029] Application effect of this embodiment

[0030] Portable gas chromatography-mass spectrometry (GC-MS) is an analytical instrument used for on-site emergency testing. It is currently widely used in my country's emergency testing field, and the Ministry of Ecology and Environment has also developed relevant standards. For example, the "Portable Gas Chromatography-Mass Spectrometry Method for Emergency Determination of Volatile Organic Compounds in Ambient Air" (HJ1223-2021) provides standardized requirements and guidance for the use of such instruments. This standard specifies methods for the on-site emergency determination of 52 volatile organic compounds in the ambient air around the site of an environmental emergency.

[0031] The performance differences between the module of the present invention and a conventional chromatographic column module were compared using the test methods and conditions specified in the aforementioned standard. The test standard gas used was a mixed standard gas of 52 volatile organic compounds specified in the standard, with each component at a concentration of 1 ppm and diluted to 50 ppb using a static diluter. The internal standard gas was a three-component mixture of 1,3,5-tris(trifluoromethyl)benzene, bromopentafluorobenzene, and p-bromofluorobenzene, with each component at a concentration of 1 ppm. With the exception of the chromatographic programmed temperature conditions, all other analytical test conditions remained consistent. Specific test condition requirements are as follows:

[0032] Sampling method: handheld probe gas sampling;

[0033] Sampling volume: 100 mL (52-component standard gas concentration 50 ppb);

[0034] Carrier gas: helium, constant flow 1.0 mL / min;

[0035] Adsorbent for adsorption tube: Tenax GR;

[0036] Adsorption temperature: 5℃;

[0037] Pre-desorption temperature: 220℃ for 0.4min;

[0038] Desorption temperature: 220℃ for 0.5min;

[0039] Chromatographic column: DB-5MS 30m×0.25mm×0.25um;

[0040] Split ratio: 15:1;

[0041] Detector: Ion trap mass spectrometer, scanning range m / z 40~300;

[0042] Traditional column module heating process: 50℃ (2min) → 20℃ / min → 120℃ → 50℃ / min → 200℃ (1.5min);

[0043] The heating process of the module of the utility model is: 20°C (2 min) → 20°C / min → 120°C → 50°C / min → 200°C (1.5 min).

[0044] As Figure 3 As shown, Figure 3 A represents the total ion current chromatogram obtained by testing 52-component standard gas with the traditional chromatographic column module. Figure 3 B shows the total ion current chromatogram obtained by testing 52-component standard gas using the module of the present invention. By comparing the spectra, it can be found that the spectra obtained using the module of the present invention have better separation, especially for the low boiling point part. Figure 4 As shown in the figure, the low-boiling point substances in the dotted frame that cannot be effectively separated on the traditional chromatographic column module are effectively separated after adopting the module of the present utility model. Figure 5 As shown in the figure, the dotted box part of the low-boiling point spectrum after partial magnification shows that only two chromatographic peaks can be observed on the traditional chromatographic column module. However, after using the module of the utility model, these two chromatographic peaks are split into three chromatographic peaks, thus significantly improving the resolution.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0046] In addition, in the present invention, unless otherwise expressly specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, the connection may be fixed, detachable, or integrated; it may be mechanical or electrical; it may be directly connected or indirectly connected through an intermediate medium; it may enable internal communication between two elements or interaction between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] The above are only preferred embodiments of the present invention, and the present invention may also have other embodiments. For those skilled in the art, it is still possible to modify the technical solutions described in the above embodiments, or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A low thermal mass chromatography column module capable of being cooled, characterized in that: The invention comprises a box body (8) and a refrigeration part connected thereto, wherein the refrigeration part is a sandwich structure consisting of a semiconductor refrigeration sheet (2), a heat dissipation fin (1) and a cold storage fin (3), wherein the hot end of the semiconductor refrigeration sheet (2) is connected to the heat dissipation fin (1), and the cold end of the semiconductor refrigeration sheet (2) is connected to the cold storage fin (3), one end of the box body (8) is connected and sealed via a box end cover (4), and a low heat capacity chromatographic column (6) is installed inside the box body (8), and the refrigeration part is connected to the box end cover (4) via the cold storage fin (3).

2. A low-heat-mass chromatographic column module capable of being cooled according to claim 1, characterized in that: A cooling fan (5) is connected below the box end cover (4) and cooperates with a plurality of ventilation openings provided on the box end cover (4).

3. The low thermal mass chromatography column module capable of being cooled according to claim 1, wherein: The inner side wall of the box body (8) is provided with a fixed bracket (7) for clamping the low heat capacity chromatographic column (6).

4. The low thermal mass chromatography column module capable of being cooled according to claim 1, wherein: A plurality of heat dissipation openings (9) are provided on the side of the box body (8).

5. The low thermal mass chromatography column module capable of being cooled according to claim 1, wherein: The volume of the cold storage fins (3) is smaller than that of the heat dissipation fins (1).

6. The low thermal mass chromatography column module capable of being cooled according to claim 5, characterized in that: Thermal conductive silicone grease is applied between the semiconductor refrigeration plate (2), the heat dissipation fins (1) and the cold storage fins (3).

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